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Temperature, precipitation and runoff prediction in the Yangtze River basin based on CMIP 6 multi-model HE Xu, MIAO Zimei, TIAN Jiaxi, YANG Liu, ZHANG Zengxin, ZHU Bin JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 1-8.   DOI: 10.12302/j.issn.1000-2006.202203028 Abstract （6347）   HTML （428）    PDF（pc） （2585KB）（3709）       Knowledge map    Save 【Objective】 This research aims to explore the impact of future climate change on predicted runoff trends in the Yangtze River basin and provide a basis for early flood warning and prevention measures in the Yangtze River basin and other regions. 【Method】 Temperature, precipitation and runoff in the Yangtze River basin from 1961 to 2014 were evaluated by using the multi-mode set average (MME) of the international coupled model intercomparison project phase 6 (CMIP 6) and the SWAT hydrological model and predicted under SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5 emission scenarios from 2020 to 2099.【Result】 (1) Compared with the single model, MME showed better performance in simulating temperature and precipitation during historical periods, with a correlation coefficient with the observation value was >0.90. Further, MME simulated the spatial distribution of temperature and precipitation well. (2) The MME analysis showed that during 2020 and 2099, temperature and precipitation increases in the Yangtze River basin under all scenarios were <50% and <20%, respectively. Simulated temperature under the SSP5-8.5 scenario was 1.23 ℃ higher than that under the SSP1-1.9 scenario, and 0.99 ℃ higher than that under the SSP1-2.6 scenario. (3) Overall, future annual runoff of the entire Yangtze River basin increased significantly and reached 40 380 m3/s under the SSP5-5.8 scenario at the end of the 21st century.【Conclusion】 Temperature, precipitation and runoff in the Yangtze River basin are predicted to increase in the future, whereas flood disasters under low emission scenarios are relatively less likely. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Analysis of chemical components in Dendrocalamus brandisii leaves based on extensive widely targeted metabolomics WANG Fei, XIE Kan, YANG Yajin, LIU Lili, CHEN Fenfen, LI Enliang, GUO Aiwei JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 241-246.   DOI: 10.12302/j.issn.1000-2006.202204026 Abstract （5225）   HTML （197）    PDF（pc） （1574KB）（1296）       Knowledge map    Save 【Objective】 This research aims to reveal the chemical components of the leaves of Dendrocalamus brandisii and accurately identify the application value of these leaves, hoping to provide a scientific basis for the development and utilization of this species. 【Method】 The research employed a Waters ACQUITY UPLC HSS T3 C18 (2.1 mm × 100 mm, 1.8 μm) liquid chromatography column. Elution was conducted at a flow rate of 0.35 mL/min using a 0.04% (volume fraction, same as below)aqueous acetic acid solution as phase A and a 0.04% acetic acid acetonitrile solution as phase B. The electrospray ion source was selected in a triple quadrupole, where detection was scanned under optimized declustering voltage and collision energy. The self-built database of Wuhan Metware Biotechnology Co., Ltd. was used to qualitatively identify substances based on secondary spectrum information. Metabolites were quantified using a triple quadrupole mass spectrometer (MRM), with the relative content of each substance determined by integrating and correcting compound characteristic ion chromatographic peak areas. 【Result】 The 407 metabolites were detected in ten categories, including 79 flavonoids, accounting for 19.41% of the total compounds. There were 61 types of lipids and 55 phenolic acids, accounting for 14.99% and 13.51% of the total detected compounds, respectively. There were 55 types of amino acids and their derivatives and 35 organic acids, accounting for 13.51% and 8.60% of the total detected compounds, respectively. Thirty-one nucleotides and their derivatives accounted for 7.62% of the total detected compounds, and 28 alkaloids accounted for 6.88% of the total detected compounds. There were 17 lignans and coumarins, accounting for 4.18% of the total detected compounds. One terpene accounted for 0.24% of the total detected compounds. There were 45 other compounds, accounting for 11.06% of the total detected compounds. 【Conclusion】 Besides basic nutritional components, these leaves contain many medicinal compounds. Flavonoid compounds, in particular, serve as one of the primary active ingredients in these leaves. These compounds have significant development and application prospects in human health and animal care. This study provides a scientific basis for further development and utilization of medicinally active substances present in the leaves of Dendrocalamus brandisii. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Changing features and influencing factors of small and micro wetlands in Wuxi City ZHANG Jiamin, LIU Xiaoyan, DENG Yi, FENG Yao, ZHU Bin, CHU Lei, ZHANG Zengxin JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 27-36.   DOI: 10.12302/j.issn.1000-2006.202204038 Abstract （4863）   HTML （262）    PDF（pc） （3155KB）（1423）       Knowledge map    Save 【Objective】 Small and micro wetlands provide several important ecological functions, such as habitat support for key species, biological transfer, hydrological regulation and water purification, education and rest. Wuxi City in China contains numerous wetlands, of which most over 8 hm2 have been protected in recent years. However, not all small and micro wetlands have been protected in Wuxi City, and research regarding spatiotemporal changes in these habitats under various factors is lacking. Thus, analyzing the temporal and spatial characteristics and driving forces of small and micro wetlands can provide a theoretical basis for wetland ecological restoration and protection construction.【Method】 Based on Landsat satellite images in 2000, 2010 and 2020, patch information of small and micro wetlands in Wuxi City were extracted using support vector machine classification and other methods. Combined with meteorological and land use data, the spatiotemporal evolution of small and micro wetlands in Wuxi City and its influencing factors were analyzed.【Result】 (1) Within the past two decades, the total wetland area in Wuxi City has decreased from 178 000 hm2 in 2000 to 104 000 hm2 in 2020. Among them, the total area of small and micro wetlands has decreased from 19 000 hm2 in 2000 to 15 000 hm2 in 2020. (2) In terms of spatial distribution, small and micro wetlands in Wuxi were mainly distributed in the county-level city Yixing, which accounted for 40.0% of the area of Wuxi City. Small and micro wetlands in Wuxi City predominantly consisted of natural wetlands, accounting for up to 61.0% and displayed marked seasonal variation characteristics. In 2020, the proportion of seasonal small and micro wetlands in the total area of small and micro wetlands was as high as 73.8%. (3) The dynamic of small and micro wetlands in Wuxi City were positively correlated with temperature and precipitation due to natural factors and human activities. Specifically, human activities had a significant impact on the decline of small and micro wetland areas, and the transformation between wetland and other land types accelerated the decline of wetlands.【Conclusion】 Wuxi City is rich in small and micro wetland resources, which are in rapid decline due to seasonal and land use changes. Thus, the protection and restoration of small and micro wetlands must be enhanced to mitigate the negative impacts imposed by different factors. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Differences in resistance of Catalpa bungei cultivars to stem rot ZHU Yanyan, JIA Ruirui, FU Yu, CHANG Lin, YUE Yuanzheng, YANG Xiulian, WANG Lianggui JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 155-165.   DOI: 10.12302/j.issn.1000-2006.202203017 Abstract （4723）   HTML （165）    PDF（pc） （4090KB）（927）       Knowledge map    Save 【Objective】 To investigate the differences in resistance to Phytophthora nicotianae (strain QS.1) infestation by Catalpa bungei cultivars and breeding methods, providing basis for C. bungei introduction and cultivation and disease resistance breeding. 【Method】 The annual seedlings of ‘Jinsiqiu’ (JSQ),‘Qiuza 1 hao’ (QZ),‘Yuqiu 1 hao’ (YQ),‘Luoqiu 1 hao’ (LQ-Z)tissue cultured seedlings,and cutting seedling‘Luoqiu 1 hao’(LQ-Q),‘Qiu5-8’(Q5-8), ‘Qiu 8-1’(Q8-1),six C. bungei cultivars were used as experimental materials and infested with P. nicotianae strain QS.1 to determine relevant osmotic substance content,protective enzyme activity and photosynthetic gas parameters. 【Result】 After infection 2-4 d by strain QS.1,all C. bungei cultivars tested were susceptible to the disease and in the case of seedlings ‘Qiuza 1 hao’ and ‘Yuqiu 1 hao’ had the weakest resistance to the disease caused by the strain QS.1,while ‘Jinsiqiu’ had the strongest resistance to the disease; as far as the cuttings of C. bungei cultivars were concerned,Q5-8 and Q8-1 were more resistant to the infection of strain QS.1; ‘Luoqiu 1 hao’ cuttings were more resistant to the disease than the histoculture seedlings,and the cuttings of other species had stronger resistance to QS.1 infection than the histoculture seedlings,except for‘JSQ’.【Conclusion】 There were differences in infection pathogenesis among different C. bungei cultivars after inoculation. The pathogenic ability of different C. bungei cultivars against P. nicotianae strain QS.1 is related to the maintenance of photosynthetic performance and the regulation of defense-related enzyme activities. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Screening and analysis of differential secondary metabolites in Castanea mollissima with different levels of resistance to Oligonychus ununguis ZHANG Xinfang, WANG Guangpeng, ZHANG Shuhang, LI Ying, GUO Yan JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 234-240.   DOI: 10.12302/j.issn.1000-2006.202209053 Abstract （4588）   HTML （167）    PDF（pc） （1947KB）（1708）       Knowledge map    Save 【Objective】 The differential secondary metabolites in chestnut (Castanea mollissima) leaves with different mite resistance levels were screened to provide a reference for the analysis of the mite(Oligonychus ununguis) resistance mechanism and the breeding of highly mite-resistant chestnut varieties.【Method】 The chestnut varieties ‘Yanxing’ and ‘Likang’ were used to identify and determine the mite resistance levels to O. ununguis with the field investigation method. Metabolomics detection was performed using ultra-high-performance liquid chromatography and tandem mass spectrometry, and the differential metabolites were screened using a combination of fold change and the variable importance in projection value. The R software (ComplexHeatmap and MetaboAnalystR package) was used to draw the clustering heat map and orthogonal partial least squares-discriminant analysis score map. Identified metabolites were annotated using the Kyoto encyclopedia of genes and genomes (KEGG) database, and the annotation results were classified by pathway types.【Result】 The resistance levels of ‘Likang’ and ‘Yanxing’ to O. ununguis were high resistance and susceptible, respectively. A total of 704 secondary metabolites were detected, including 165 differential metabolites. The content of 73 metabolites in ‘Likang’ was significantly higher than in ‘Yanxing’, and the content of 92 metabolites was lower in ‘Likang’ than in ‘Yanxing’. The types of differential metabolites included 56 phenolic acids, 60 flavonoids, 19 lignins and coumarins, four tannins, five alkaloids, 16 terpenoids and five other types. Flavonoids and phenolic acids accounted for 36% and 34%, respectively. Metabolites present only in ‘Likang’ included caffeoylcholine-4-O-glucoside, 3-hydroxy-5-methylphenol-1-O-(6'-galloyl)glucoside, tricin-7-O-glucuronide, 6'-trans-cinnamoyl-8-epikingisidic acid, lariciresinol-4'-O-glucoside, albanol B and sanguiin H11. There were 15 metabolites present only in ‘Yanxing’, including 4-methyl-5-thiazoleethanol, 2,4-dihydroxybenzoic acid, isofraxidin, salicin and roxburic acid. Thirty-three differential metabolites in ‘Yanxing’ and ‘Likang’ were annotated to 12 metabolic pathways.【Conclusion】 The secondary metabolic profiles between the mite-susceptible variety ‘Yanxing’ and the highly resistant variety ‘Likang’ differed. Secondary metabolites that may be related to chestnut mite resistance were prunetin, epigallocatechin, caffeic acid, ferulic acid, several lignans and 4-methyl-5-thiazoleethanol. The differential secondary metabolites were mainly annotated and enriched in the flavonoid biosynthesis pathway and the flavone and flavonol biosynthesis pathway. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Systematic classification of gymnosperms: past, present and future YANG Yong JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (3): 14-26.   DOI: 10.12302/j.issn.1000-2006.202301020 Abstract （4501）   HTML （323）    PDF（pc） （1706KB）（1715）       Knowledge map    Save The botanical history of gymnosperm classification was reviewed and dividied into six major phases since the initiation of modern taxonomy in 1753 according to landmark concepts or creative classifications. The first phase lasted from Linnaeus to Brown during which the concept of gymnosperm was not conceived, and gymnosperms were not treated as a taxon. This phase was represented by the sexual system of Linnaeus. The second phase was from Brown to Brongniart. In this phase, the concept of gymnosperms was proposed and gradually accepted by botanists at that time, and Brongniart treated gymnosperms as a group in his classification system though the linear sequence, family delineation and relationships among taxa were ambiguous. The third phase was from Brongniart to Braun. In this phase, the gymnosperms were treated as a group within dicotyledons, the classification of Bentham & Hooker was considered as the representative classification systems. The fourth phase was from Braun to Pilger. During this period, the gymnosperms were treated as a separate taxon from angiosperms, the spermatozoids of cycads and ginkgo were discovered, the main lineages of gymnosperms became established, but the family delineation remains ambiguous, representative systems include Eichler and Engler. The fifth phase was from Pilger to Christenhusz et al.. Numerous classifications of gymnosperms were proposed in this phase, various categories were applied to lineages of gymnosperms, different lines of evidence were obtained and utilized including morphology, anatomy, embryology, phytochemistry, palaeobotany, cladistics, the focuses of debates were mainly on the relationships and systematic positions of ginkgo, taxads, and gnetophytes, and the taxonomic delineation of Podocarpaceae, Taxodiaceae and Cupressaceae, the classification systems of Pilger and Wanchun Cheng were representative in this phase. The sixth phase was from Anderson et al. till now. In this phase, people accepted the principles of cladistics, and conducted phylogenetic studies using DNA sequences, and also integrated different lines of evidences in taxonomy. The new classification of gymnosperms proposed by Yang et al. was introduced and the features of this new classification was discussed. Future studies should focus on species delimitation based on Genomic barcoding, integrative taxonomy, and conservation biology. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Effects of the compound inoculation of two arbuscular mycorrhizal(AM) fungi on the resistance of Populus pseudo-cathayana × P. deltoides leaves to Hyphantria cunea FANG Jing, ZHANG Shuman, YAN Shanchun, WU Shuai, ZHAO Jiaqi, MENG Zhaojun JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 144-154.   DOI: 10.12302/j.issn.1000-2006.202209054 Abstract （4469）   HTML （189）    PDF（pc） （2724KB）（1097）       Knowledge map    Save 【Objective】 In order to study a new way of biological control of pests on Populus pseudo-cathayana × P. deltoides leaves, the effects of compound inoculation with arbuscular mycorrhizal (AM) fungi on the resistance of P. pseudo-cathayana×P. deltoides leaves to Hyphantria cunea were investigated. 【Method】 One-year-old P. pseudo-cathayana × P. deltoides cuttings were inoculated with Rhizophagus intraradices (RI) and Funneliformis mosseae (FM) by single and mixed inoculation (M) in a greenhouse, with no inoculation (CK) as the control. The chemical defense ability of secondary metabolites, defense enzymes and protease inhibitors in poplar leaves was determined, and the larva of H. cunea was used as a bioassay object to determine its anti-insect effect.【Result】 In 120 days, the mycorrhizal infection rate, arbuscular growth rate and number of vesicles in the root of the M group were higher than those of the FM and RI groups. Meanwhile, the M group could improve the chemical defense ability of the leaves of P. pseudo-cathayana × P. deltoides to a certain extent. The contents of total alkaloids and cellulose and the activities of peroxidase (POD), catalase (CAT), lipoxygenase (LOX), polyphenol oxidase (PPO), chymotrypsin inhibitor (CI) and trypsin inhibitor (TI) in leaves were significantly higher than those in the RI, FM and CK groups (P<0.05). The food intake, fecal output, cellulase activity, acetylcholinesterase (AchE) activity and multifunctional oxidase (MFO) activity of the third instar larvae in the M group were significantly lower than those in the FM, RI and CK groups (P<0.05). The body length, food availability, trypsin activity, carboxylesterase (CarE) activity, and glutathione S-transferase (GSTs) activity of the third instar larvae were significantly higher than those of the RI and FM groups (P<0.05). The food consumption rate and α-amylase activity of the third instar larvae did not significantly differ from those of the RI group, and the body weight of the third instar larvae did not significantly differ from those of the FM group. Body weight, food intake, food consumption rate, cellulase activity, GSTs activity, CarE activity, AchE activity and MFO activity of the fourth instar larvae were significantly lower than those of the FM, RI and CK groups (P<0.05), the fecal output of the fourth instar larvae was significantly lower than that of the RI and CK groups (P<0.05), and the trypsin activity of the fourth instar larvae was significantly higher than that of the other three groups (P<0.05). The body length and food availability of the fourth instar larvae did not significantly differ from those of the RI group, and the α-amylase activity of the fourth instar larvae did not significantly differ from those of the FM and RI groups. The body length, body weight, food intake, fecal output, food utilization, α-amylase activity, cellulase activity, GSTs activity, CarE activity, and MFO activity of the fifth instar larvae were significantly lower than those in the FM, RI and CK groups (P<0.05). The food consumption rate of the fifth instar larvae was significantly lower than that in the FM and RI groups, and the AchE activity of the fifth instar larvae was significantly lower than that in the FM group (P<0.05). The trypsin activity of the fifth instar larvae was significantly higher than that of the other three groups (P <0.05).【Conclusion】 The mixed inoculation of RI and FM could induce the chemical defense performance of P. pseudo-cathayana × P. deltoides leaves in the aspects of secondary metabolites, defense enzymes, and protease inhibitors. The anti-insect performance of combined RI and FM inoculation was better than that of single RI and FM inoculation and no AM fungi inoculation and had certain inhibitory effect on the larva of H. cunea. In practical application, combined RI and FM inoculation can be prioritized. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Research progress and prospects of biological basis in Magnolia biondii YIN Zengfang, OU Xiang, CHEN Yao, YANG Aixiang, SUN Liyong JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 256-262.   DOI: 10.12302/j.issn.1000-2006.202307006 Abstract （4394）   HTML （174）    PDF（pc） （2053KB）（1548）       Knowledge map    Save Magnolia biondii is an economically important tree in China, serving various medicinal, material and ornamental purposes. The species has extensive use in landscaping and practical applications. Despite numerous studies focusing on the growth and breeding characteristics of M. biondii, there remains a lack of a systematic summary of the results from basic biological research. This paper comprehensively reviews research advancements in various aspects of M. biondii, including individual growth and development characteristics, rapid propagative techniques, germplasm resource selection, genomics overview and other research areas. We present essential findings from basic biological research and discuss future research directions. Emphasis is given to furthering research efforts in breeding techniques, innovating germplasm resources, screening for quality and functional traits, and elucidating regulatory mechanisms. This will establish a scientific foundation for studying on development and application of M. biondii germplasm resource, and for understanding the growth regulation mechanisms within Magnoliaceae. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Optimization of the tissue culture technology system of Mytilaria laosensis trees SUN Xugao, TAO Jialu, XIE Wei, SHI Jie, ZHANG Baojin, DENG Xiaomei JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 69-78.   DOI: 10.12302/j.issn.1000-2006.202303008 Abstract （4366）   HTML （210）    PDF（pc） （2211KB）（1108）       Knowledge map    Save 【Objective】 Mytilaria laosensis is an evergreen, broad-leaved tree with a wide range of suitable habitats and good economic and ecological protection. The seedling is mostly used for cultivation. Grafting and cutting techniques are still experimental, and few reports on tissue culture techniques exist. Therefore, it is of great significance to establish an efficient tissue culture technology system for M. laosensis and to provide technical support for promoting its clone in the future. 【Method】 With the semi-lignified bud at the base of the superior tree as explants, through the processes of primary axillary bud induction, secondary proliferation culture, rooting culture, the optimal explant collection time, the basic breeding and rooting culture medium, and the type and concentration ratio of plant growth regulator were studied. 【Result】 There were significant differences in the effect of different sampling times on the induction of M. laosensis. The best induction of explants was collected in October 2022, with a survival rate of 32.38%. Treatment with different hormone concentrations significantly affected the time required for bud germination and the growth status of explants. The optimal formula for axillary bud induction was MS+6-BA 0.5 mg/L+NAA 0.02 mg/L, the induction rate was 100%, and the germination time was 4.07 d. The selection of different basic mediums significantly affected the proliferation of M. laosensis. MX medium had the highest average shoot length (4.47 cm) and the largest proliferation coefficient (4.41), respectively, which were significantly higher than those of other basic media (1/2 MS, MS, DKW, WPM), and the proliferation buds grew strongly, increased quickly and had a good effect. Different hormone types and treatment concentrations significantly affected the proliferation and rooting effects of M. laosensis. The optimal breeding medium was MX (modified WPM) + 6-BA 1.0 mg/L+NAA 0.05 mg/L, and the proliferation coefficient reached 4.94. The buds grow vigorously. The optimal rooting medium was MX+NAA 0.3 mg/L, the rooting rate was 100%, the average root number was 13.18, root growth was robust, and the transplanting survival rate reached 92.3%. 【Conclusion】 The induction survival rate of M. laosensis explants was related to the location and time of material collection. October was the best time to collect explant material in Guangdong. In the case of a low proliferation coefficient of the MS basic medium, switching to an MX (modified WPM) medium could significantly increase the proliferation succession factor. Then, the induction medium, breeding medium, and rooting medium were optimized, which helped establish the tissue culture system of the superior tree of M. laosensis and improved the quality and efficiency of the tissue culture. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Effects of different shedding time on aroma and nutrients of Torreya grandis ‘Merrillii’ seed kernel WEI Xixing, HU Yuanyuan, ZHU Guangxia, YU Weiwu, ZHANG Zuying, WU Jiasheng, SONG Lili JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 51-60.   DOI: 10.12302/j.issn.1000-2006.202308024 Abstract （4287）   HTML （241）    PDF（pc） （2554KB）（2327）       Knowledge map    Save 【Objective】 The objectives of this study were to elucidate the effect of aril on the quality of Torreya grandis kernel, and compare the aroma components and nutrients of kernels with different peeling times. 【Method】 Aroma components of kernels were determined with different peeling times (0d, kernel sample with aril removed from seed on harvest day; 10CK, kernel sample with aril removed from seed on harvest day and stored at 90% relative humidity and 25 ℃ for 10 days; 10BLACK, kernel sample with aril removed from seed 10 days after harvesting) by headspace solid-phase microextraction and gas chromatography-mass spectrometry (SPME/GC-MS). The characteristic aroma components of kernels at different peeling times were detected, and differences in their nutrient content were also compared. 【Result】 (1) A total of 57 aroma components were identified under different treatments, including terpenes (16 species), alcohols (14 species), benzenes (8 species), aldehydes (6 species), esters (1 species), ketones (7 species), acids (2 species), and ethers (3 species), among which the content of terpenes was the highest. Principal component analysis showed that the main aroma components of the 0d and 10CK samples were terpene and benzene, respectively, whereas those of 10BLACK were ether, ketone, aldehyde, ester, alcohol, and acid compounds. (2) Venn plot analysis showed that the number of characteristic substances of 0d, 10CK and 10BLACK was 14, 10 and 16, respectively, among which 4-methyl-1-(1-methylethyl)-, Bicyclo[3.1.1]hept-3-en-2-ol, 4,6,6-trimethyl-, and Bicyclo[3.1.1]hept-3-en-2-one, 4,6,6-trimethyl-, (1S)- had a peculiar odor. (3) Compared to 0d samples, the crude fat, soluble sugar, and soluble protein content of 10CK samples was significantly higher (P<0.05), whereas the starch content was significantly lower (P<0.05). There was no significant difference in crude fat, soluble sugar, starch, and soluble protein content between 10BLACK and 10CK samples. 【Conclusion】 Compared to kernels from seed peeled off on harvest day, those peeled at 10 days after harvesting formed more abnormal odors. Therefore, T. grandis ‘Merrillii’ should be promptly peeled after picking, otherwise it will produce odorous aromatic substances that affect the flavor of its kernel. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Advancements in the research of miRNAs associated with plant drought and salt stress responses SONG Zihe, ZHEN Yan JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (4): 1-11.   DOI: 10.12302/j.issn.1000-2006.202305016 Abstract （4287）   HTML （306）    PDF（pc） （1798KB）（1192）       Knowledge map    Save China is a maritime power with a long coastline and abundant coastal resources. However, this long costline brings vast areas of saline-alkali land. Additionally, global warming has led to more frequent seasonal drought. Under such extreme conditions, the survival rate of most plants is very low. Therefore, research on the molecular mechanisms of drought resistance and salt tolerance is particularly important. Improving the survival rate of plants in arid and saline-alkali areas can bring significant ecological benefits and economic value. Non-coding RNA (ncRNA) is a class of genetic information molecules transcribed from the genome that do not encode proteins. As a major focus of epigenetic research, ncRNAs were once considered the “dark matter” or “transcriptional noise” of the genome. The most well-known type of ncRNA is microRNA (miRNA), a highly conserved class of short non-coding small RNA molecules that are 20-24 nucleotides in length. They regulate the growth and development of organisms by cleaving and degrading target gene transcripts or inhibiting the translation of target genes through complementary base pairing with target sites. With the development of miRNA research methods such as small RNA sequencing and degradome sequencing, an increasing number of miRNAs and their target genes has been reported in animals and plants. Their biological synthesis, processing, maturation, and functional effects have been elucidated. Plant miRNAs complementarily pair with their target genes mostly in the open reading frame, with a full or nearly full complementarity to the target sequences. These characteristics stimulated the rapid development in plant miRNA research, and a large amount of research has revealed important regulatory roles of miRNAs in plant growth, development, and stress responses. This article provides a systematic review of the features, synthesis process, mode of action, and research progress of plant miRNAs in drought and salt resistance. We summarizes the main techniques and strategies for plant miRNA research in recent years, discuss the existing problems and prospects, and reveals the regulatory mechanisms of miRNA in plant drought and salt resistance, providing a basis for generating new varieties of drought and salt resistance. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Potentiality evaluation of Pleurotus citrinopileatus cultivation with Tetradium ruticarpum branch sawdust YE Jianqiang, ZHANG Fangfang, CHEN Lixin, HUANG Zhuozhong, LAN Taoju JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 166-174.   DOI: 10.12302/j.issn.1000-2006.202203016 Abstract （4223）   HTML （154）    PDF（pc） （1968KB）（1099）       Knowledge map    Save 【Objective】 This study assesses the potential of using Tetradium ruticarpum branch sawdust for cultivating edible mushrooms. The research is significant for extending the T. ruticarpum industry chain and expediting branch degradation. It also offers a reference for efficient utilization of T. ruticarpum branches. 【Method】 The Pleurotus citrinopileatus, known for its short cultivation cycle, was chosen as the experimental strain. The nutritional content of T. ruticarpum branch sawdust, mixed wood sawdust and cottonseed hulls was analyzed. Tests involved replacing 20% (treatment 1), 40% (treatment 2), 60% (treatment 3), 80% (treatment 4) and 100% (treatment 5) of the mixed wood sawdust with T. ruticarpum branch sawdust. The effects on agronomic traits, fungus bag substrate degradation, and economic benefits in cultivating P. citrinopileatus were examined, comparing with the mixed wood sawdust (CK1) and cottonseed hulls (CK2) formulations. 【Result】 The cellulose, hemicellulose and lignin contents of T. ruticarpum sawdust were comparable to those of mixed wood sawdust (P>0.05), but its hemicellulose and lignin contents were 39.64% and 16.55% lower than those of cottonseed hulls. Its crude protein content was 4.25 times and 1.91 times that of mixed wood and cottonseed hulls, respectively. Its carbon-nitrogen ratio was 0.24 and 0.55 times that of the two. Selenium was not detected in mixed wood. Selenium content in T. ruticarpum sawdust was 7.69 times that of cottonseed hulls. Using T. ruticarpum sawdust increased inputs but had minimal impact on mycelium germination, growth and harvest times. It accelerated post-harvest recovery, significantly boosted yield, substrate utilization and economic benefits. Higher mycelial growth rates and fungus bag survival rates of 100% were observed in treatments 3,4 and 5, with no significant differences compared to CK2 in treatments 4 and 5. Biological efficiency was higher in treatments 2, 3, 4 and 5 than that of CK2, with treatment 4 yielding the best results. However, the total fresh weight was significantly lower than that of CK2. Fruiting rate higher than CK1 and CK2 was observed in treatments 3 and 4. Substrate degradation was the highest in treatment 4, with substrate utilization at 71.88%, cellulose degradation at 78.08%, hemicellulose degradation at 86.38%, and lignin degradation at 71.18%. Treatment 4 also showed the best economic performance, significantly better than CK1, and nearly equivalent to CK2, with only 0.03 yuan lower in profit per bag. It significantly reduced inputs and improved input-output ratio. 【Conclusion】 The T. ruticarpum branch sawdust is a material richer in crude protein and selenium than mixed wood sawdust and cottonseed hulls, and can replace pure mixed wood sawdust and pure cottonseed hulls for cultivating P. citrinopileatus. Replacing 80% of the mixed wood sawdust can guarantee a good survival rate of fungal packages and also a relatively high mycelial growth rate, yield, fourth flush yield rate, high material degradation and economic performance. It is a excellent edible fungi raw material, with a specific formulation of 62.4% (mass fraction, the same below) T. ruticarpum branch sawdust, 15.6% mixed wood sawdust, 20.0% wheat bran, 1.0% lime, and 1.0% gypsum. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Modelling the potential distribution area of Populus davidiana in China based on the Biomod2 GAO Minglong, TIE Niu, ZHANG Chen, LI Fengzi, WU Yahan, LUO Qihui, WANG Zirui, LIU Lei, SA Rula JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 247-255.   DOI: 10.12302/j.issn.1000-2006.202205022 Abstract （4187）   HTML （181）    PDF（pc） （3857KB）（1255）       Knowledge map    Save 【Objective】 This study aims to investigate the effects of changes in environmental factors on the distribution of Populus davidiana, and to provide theoretical support for the conservation and development of P. davidiana resources. 【Method】 This study applied Biomod2 to simulate changes in the spatial distribution pattern of P. davidiana in China's potential distribution areas under three future climatic conditions based on 134 geographical distribution data points of P. davidiana in China, combined with 18 climatic, soil and topographic factors. Then a combinatorial model based on the Biomod2 package was consturcted and identified the main environmental variables affecting the distribution of P. davidiana were identified. 【Result】 The current potential distribution areas of P. davidiana in China were mainly located at higher latitudes or higher altitudes on both sides of the 400 mm precipitation line, with a total area of about 1 560 340.9 km2, of which the Greater Khingan Mountains, Changbai Mountains, Taihang Mountains, Qinling Mountains, southern foot of Qilian Mountains, Hengduan Mountains, Yunnan-Guizhou Plateau and other areas are the highest suitable areas for P. davidiana. Under future climatic conditions, the overall trend of suitable areas for P. davidiana will shrink to southwest China, and the overall trend of suitable areas was decreasing. The ensemble model constructed based on the five optimal single models had better prediction results for suitable areas for P. davidiana compared to the single model, and the area under the receiver operating characteristic curve and true skill statistics were distributed as 0.91 and 0.73, with higher prediction accuracy. 【Conclusion】 The spatial distribution pattern of P. davidiana in China was mainly influenced by water and heat conditions, while altitude was also an important factor affecting its distribution. Under future climatic conditions, the area of P. davidiana distribution will gradually decrease based on the degree of climate warming. When planting P. davidiana for timber forests and as an ecological public welfare forest species, planting sites should be selected in areas where habitat suitability will not change significantly in the future, to reduce future losses because of climate change. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Studies on the phenotypic traits and quality characteristics of seven superior tree nuts of Torreya grandis ‘Merrillii’ TAO Tao, LIU Yaohui, XUE Zhongjun, GAO Yue, YUAN Luhong, ZHENG Fen, WU Wei, HUANG Jieying JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 37-44.   DOI: 10.12302/j.issn.1000-2006.202211034 Abstract （4120）   HTML （251）    PDF（pc） （1523KB）（1670）       Knowledge map    Save 【Objective】 This study investigated seven nuts of Torreya grandis‘Merrillii’ to compare and analyze the primary physical properties and content of the main components, understand the quality of T. grandis in Yi County, and provide a theoretical basis for the selection, development, and utilization of improved varieties of T. grandis ‘Merrillii’【Method】 Seven T. grandis were selected ‘Merrillii’ germplasms from Yi County, southern Anhui Province; measured their phenotypic characteristics, mineral elements, nutrient composition, fatty acid composition, and 29 additional physical and chemical properties; and carried out correlation and cluster analyses on the measured data. 【Result】 The phenotypic characteristics and internal quality indices of T. grandis ‘Merrillii’ differed significantly (P < 0.05). The crude protein content ranged from 6.67% to 14.69%. The crude fat content varied from 36.20% to 55.51%, among which the highest average content of polyunsaturated fatty acids was linoleic acid at 47.81%, followed by chrysotile acid at 12.20%. The total potassium (TK) content varied from 0.77% to 1.39%, and there was a significant difference between different superior plants (P < 0.05). 【Conclusion】 According to the comprehensive analysis, the crude protein content of the oblong-shaped Zhujiyihao and Zhejiangxifei was higher than that of T. grandis ‘Merrillii’ types with a round appearance, while the oil acid value of the oblong T. grandis ‘Merrillii’ kernel was lower, and the oil quality was better. Acid value, nuclear shape index, and oleic acid content can be used as the optimum indexes for screening superior plants of T. grandis ‘Merrillii’. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Effects of vegetation distribution on the carbon neutrality performance of urban green spaces YANG Yunfeng, YU Chunhua JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 209-218.   DOI: 10.12302/j.issn.1000-2006.202206031 Abstract （4103）   HTML （166）    PDF（pc） （2291KB）（3137）       Knowledge map    Save 【Objective】 To provide a theoretical reference for urban green space construction under the “Dual Carbon” goal, we established a carbon neutrality performance evaluation system and analyzed the impacts of vegetation distribution on the carbon neutrality performance of green spaces. 【Method】 Based on life cycle assessments, green space construction was divided into three stages: material production and transportation, site construction and planting, and green space operation and maintenance, which were combined with open, semi-open, covered and closed vegetation types. Carbon emissions and sink simulations were performed to analyze the carbon neutrality performance.【Result】 When the vegetation type changed from openness to closedness, the total carbon emissions increased rapidly and the trend accelerated. The proportions of carbon sources in the three stages decreased, leveled out and increased, respectively. The total carbon sink and net carbon neutrality both increased gradually. The number of years of carbon neutrality decreased gradually, from 43.9 years for open vegetation to 24.6 years for closed vegetation. These trends implied that there was a limit to the degree of vegetation shading for improving the carbon neutrality performance.【Conclusion】 Vegetation type clearly has an impact on the carbon neutrality performance. In terms of carbon sources, strategies such as reducing machinery use, selecting environmentally friendly materials, controlling construction damage, and improving energy utilization efficiency are suggested. For carbon sinks, strategies such as selecting tree species that have dominant local carbon sinks, adjusting the structures of vegetation communities, and regulating and managing green spaces along with life cycles are suggested. Ultimately, we postulate that green space carbon neutrality performance can be achieved by adapting to local conditions. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Dynamic content changes of parthenolide from four Magnolia species LIU Jingsheng, TANG Xinwei, ZHOU Hu, CHEN Lei, DAI Xiaogang, YIN Tongming JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 227-233.   DOI: 10.12302/j.issn.1000-2006.202210036 Abstract （3880）   HTML （161）    PDF（pc） （1481KB）（1092）       Knowledge map    Save 【Objective】 The contents of parthenolide from different tissues were measured in four species of Magnolia, and contents of parthenolide were also measured at different growth periods, different tree ages and different production areas in tree species with high level of parthenolide, which will provide useful lessons for the breeding programs and for the planting of medicinal plant varieties from Magnoliaceae family.【Method】 Taking Magnolia denudata, M. biondii, M. grandiflora and M. delavayi as materials, the contents of parthenolide were measured by high performance liquid chromatography (HPLC) in leaves, buds and root barks. Root barks from M. biondii at different growth stages, different tree ages and different production areas are measuring for its parthenolide contents. 【Result】 Among different tissues from the four species, root barks of M. biondii has the highest contents of parthenolide with an average level of 5.10%, and the contents falls to 0.72% in M. denudata, but parthenolide was not detected in M. grandiflora and M. delavayi root barks. All leaves from the four species contented parthenolide with the trace level between 0.06% and 0.59%. Only the buds of M. biondii and M. grandiflora contains parthenolide with the average level of 0.88% and 0.08% separately. The contents of parthenolide in root barks with two-year, three-year and four-year old stage of M. biondii were 2.43%, 4.07% and 4.31% separately, and the contents of two-year old was significantly different from three-year and four-year old, but no significant difference was detected from three-year and four-year old tree. During the growth period of one year, parthenolide reached the highest level of 6.04% in February, which was significantly different from that in April and December of the previous year. The contents of parthenolide in root barks of M. biondii varied from 3.22% to 5.51% in five different production areas, and the analysis of variance showed that only the tree growing in Lin'an, Zhejiang Province were significantly different from the other four sites. 【Conclusion】 The contents of parthenolide were compared in different tissues from four Magnolia species, and found that the root barks of M. biondii contained the highest level of parthenolide among the four species with different tissues. The optimal tree age determined for havesting parthenolide was three and the best harvest time was mid-February based on the comparison of root barks parthenolide contents from different tree ages and different grown stages. When aiming at harvesting a single compound of parthenolide, Nanjing and Xinyi City in Jiangsu Province and Xiangyang in Hubei Province can introduce the tree of M. biondii for parhtenolide extraction from its root bark. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Establishment and application of a flow cytometry method for chromosome ploidy identification of Cyclocarya paliurus SONG Ziqi, BIAN Guoliang, LIN Feng, HU Fengrong, SHANG Xulan JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 61-68.   DOI: 10.12302/j.issn.1000-2006.202302014 Abstract （3858）   HTML （215）    PDF（pc） （2262KB）（1204）       Knowledge map    Save 【Objective】 To provide technical support and basic data for the germplasm identification and genetic breeding of Cyclocarya paliurus, this study determined the chromosome ploidy using flow cytometry. 【Method】 C. paliurus leaves were used as study materials to compare the ploidy detection effects of different nuclei isolation buffers, centrifugation treatments, and leaf preservation methods. The ploidy identification method for C. paliurus using flow cytometry was as follows: 0.50-1.00 cm2 leaves of the reference sample and the test sample were mixed and chopped with 1 mL of mGb buffer. After filtration, 20 μL PI was added for staining for 1 min. The ploidy of 1 395 C. paliurus germplasm resources was determined by the established method. 【Result】 The optimal choice for isolating nuclei and achieving a clear peak in the resulting nucleus suspension was the use of Modified Gitschier buffer (mGb). Nuclear suspensions could be directly stained after filtration without centrifugation treatment. The optimal detection effect was obtained for leaves preserved at 4 ℃, and the most suitable storage time was 7 d. Drying leaves with silica gel yielded superior test results compared to freezing them, and the most suitable storage time for silica gel drying was 150 d. The coefficients of variation of 100 test samples ranged from 2.13% to 5.04%. If the estimated value of ploidy was 1.80-2.40, the sample was identified as diploid. If the estimated value of ploidy was 3.60-4.20, the sample was identified as tetraploid. When the estimated value of ploidy was 3.00 ± 0.40, the reference sample with the same ploidy as the initial judgment was used for the second detection. Using this method for the ploidy identification of 1 395 germplasm resources 104 diploids and 1 291 tetraploids were detected. 【Conclusion】 Samples with an abnormal estimated value of ploidy could be identified quickly by the second detection with the same ploidy standard. The method is simple, efficient, and accurate, and provides an effective method for ploidy identification of C. paliurus germplasm. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Taxonomy and diversity of the genus Cupressus: current status and recommendations LI Jialiang, WU Dayu, MAO Kangshan JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (3): 36-45.   DOI: 10.12302/j.issn.1000-2006.202405017 Abstract （3677）   HTML （238）    PDF（pc） （2256KB）（2996）       Knowledge map    Save Cupressus L., the type of Cupressaceae family, is typified by Cupressus sempervirens L. Over the years, as many other species have been discovered and described, and with advances in phylogenetics and population genetics, the taxonomy and species diversity within the genus Cupressus have been subjects of continuous debate. Traditionally, the Cupressus sensu lato includes species from true Cypresses sensu stricto and New World cypresses (Hesperocyparis Bartel & R.A.Price), while the Cupressus s. s. comprises all Old World species except the Vietnamese golden cypress (Xanthocyparis vietnamensis Farjon & T.H.Nguyên) found in Vietnam. Christenhusz et al. defined the broadest interpretation of Cupressus (Cupressus sensu Christenhusz) which encompasses four groups: true cypresses (Cupressus s.s.), Vietnamese golden cypress, Nootka cypress (Callitropsis nootkatensis (D.Don) Oerst), and New World cypresses. These ideas have been challenged by recent phylogenomic studies. Recent studies have shown that Cupressus s.l. is non-monophyletic, Cupressus s.s. is monophyletic and forms a sister group with the genus Juniperus. The common ancestor of these two is a sister group of the common ancestors of the Xanthocyparis, Callitropsis and Hesperocyparis. Based on current research, the true cypresses should encompass 14 species, including one hybrid. This paper offers new perspectives on previous contentious taxonomic treatments, for instance, reclassifying Cupressus rushforthii Maerki & J.Hoch as a synonym of Cupressus austrotibetica Silba, and confirming that Cupressus × jiangeensis N. Zhao is a hybrid offspring of the Cupressus fallax Franco and Cupressus funebris Endlicher. Additionally, Cupressus ×wangii J.Hoch, Maerki & Rushforth has been reduced to a synonym of Cupressus × jiangeensis. To avoid confusion, it is recommended to rename the recently discovered tallest tree species in Bomi County, Cupressus austrotibetica, to “西藏高柏” (Xizang tall cypress) in Chinese, and the cypress predominantly found in Nepal, Cupressus torulosa D.Don ex Lamb., is referred to as “喜马拉雅柏” (Himalayan cypress) in Chinese, instead of “西藏柏木” (Xizang Cypress). To ensure accuracy and scientific validity in future studies on species delineation within the genus, we recommend integrating multidimensional data from morphology, genetics, ecology and biogeography. This approach will help the reducing of classification confusion and support biodiversity conservation efforts more effectively. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Effect of red and blue light quality on growth physiological and flavonoid content of Ginkgo biloba seedlings WANG Gaiping, ZHANG Lei, CAO Fuliang, DING Yanpeng, ZHAO Qun, ZHAO Huiqin, WANG Zheng JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 105-112.   DOI: 10.12302/j.issn.1000-2006.202303030 Abstract （3639）   HTML （200）    PDF（pc） （2032KB）（1205）       Knowledge map    Save 【Objective】 This research aims to explore the effects of red and blue light quality on growth characteristics, morphogenesis and accumulation of secondary metabolites of Ginkgo biloba seedlings, in order to provide theoretical basis for selecting suitable light environment and improving leaf quality of G. biloba seedlings.【Method】 Taking 1-year-old seedlings of G. biloba as materials, under LED conditions,three different light qualities were set, namely red light(R), multiple light (light intensity ratio of red to blue is 1∶1, M) and blue light(B),and white light(W) was used as control to explore the dynamic change rule of growth physiology, photosynthetic capacity and flavonoids accumulation.【Result】 B treatment significantly increased the seedling height(P<0.05), and which of the R and M treatment was lower than W(CK). The leaves biomass, total biomass and leaves mass ratio of G. biloba seedlings under different light quality were lower than W(CK). R and M treatment were beneficial to the distribution of the biomass to the root, while B treatment was beneficial to the distribution of biomass to the stem. The leaves morphogenesis was significantly affected by different light quality, and the leaves width and area were lower than W(CK). R treatment significantly extended the petiole (P<0.05). M and B treatment significantly increased the contents of total chlorophyll and carotenoid, while R treatment had the opposite effect, and chlorophyll content increased with the extension of light treatment time. Under different light quality, net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) of G.boloba seedling reached the maximum value at 84 days, and intercellular CO2 concentration(Ci) changed little under different treatments.In the same treatment group,Pn and Tr were significantly lower than W(P<0.05), Gs under M and B treatment is also lower than that under W treatment.The contents of total flavonoids in G. biloba leaves were B, M, W, R treatment from high to low,and contents of total flavonoids under B and M treatment were significantly higher than that under W treatment, while contents under R treatment were on the contrary(P<0.05). The flavonoid yield of G. biloba single plant was also determined, and it was found that the falvonoid yield under B treatment was increased 75.65% than that under W treatment.【Conclusion】 Light quality treatment affects the growth and significant increase the accumulation of flavonoids of G. biloba, B and M treatment are ideal light quality. The results can provide theoretical basis for the application of light quality in the cultivation of G. biloba. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Phylogenetic analysis of Sorbus ser. Folgnerianae (Rosaceae) MA Jianhui, CHEN Xin, GENG Liyang, TANG Chenqian, WEI Xueyan JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (4): 25-36.   DOI: 10.12302/j.issn.1000-2006.202205003 Abstract （3575）   HTML （214）    PDF（pc） （11845KB）（732）       Knowledge map    Save 【Objective】To test whether Sorbus ser. Folgnerianae is a monophyletic group and to reconstruct the phylogenetic relationship among three species, S. dunnii, S. folgneri and S. hemsleyi.【Method】Morphological characteristics of leaves, flowers and fruits of Ser. Folgnerianae species were compared through specimen examination and field observation. Phylogenetic relationships within Ser. Folgnerianae were analyzed based on the comparison of the plastid genomes, repeat sequences, sequence variations of the five plastid genomes newly sequenced including three Ser. Folgnerianae species and S. megalocarpa from Sect. Aria, together with other plastid genomes available in this genus, using representatives of related genera in Rosaceae and Barbeya oleoides (Barbeyaceae) as the outgroups.【Result】Species of Ser. Folgnerianae can be easily distinguished from each other in the number of styles, color of anthers, fruit morphology and the persistence of calyx. Plastid genomes of five samples have a similar structure, gene content and organization. This sizes of plastid genomes range from 159 898 to 160 755 bp, with the GC contain range between 36.4% and 36.6%. All plastid genomes contain 113 unique genes (79 protein-coding genes, 30 tRNA genes and four ribosomal RNA genes). The IR region has two pseudogenes, rps19Ψand ycf1Ψ, with different extension lengths. 48-54 simple sequence repeats (SSRs), 36-49 long repeats sequences (LRSs) and 20 highly variable regions in the noncoding regions are identified as the most promising potentially variable makers for population genetics, species delimitation and phylogenetic studies. Phylogenetic analyses under ML/BI indicated that Sorbus is polyphyletic and the six sections within it are all monophyletic. Although, three sampled species of Ser. Folgnerianae are clustered in one group, S. Alnifolia of Ser. Alnifolia is more closely related to S. dunnii and S. folgneri than S. hemsleyi.【Conclusion】Sorbus ser. Folgnerianae is not monophyletic. Morphological characteristics and plastid genome analysis are effective in understanding the phylogenetic relationship in Ser. Folgnerianae. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Effects of rejuvenation and hormone treatment on the rooting of softwood cuttings of Quercus texana and anatomical observations of rooting BU Xiaoting, FU Wei, LI Shuxian, XU Zhibiao, PENG Daqing, XU Linqiao JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 129-136.   DOI: 10.12302/j.issn.1000-2006.202209004 Abstract （3516）   HTML （183）    PDF（pc） （2446KB）（1277）       Knowledge map    Save 【Objective】 This study was performed to investigate the effects of rejuvenation and hormone treatment on the rooting of Quercus texana cuttings and obverse the formation process of adventitious roots during the rooting process. This was done to explain the reasons behind the difficulty of rooting Q. texana cuttings to provide a theoretical basis and technical reference for the subsequent cutting propagation of Q. texana.【Method】 Using the rejuvenated (seedlings after the flat stubble of the six-year-old parent stocks) and the annual semi-woody branches cut from the six-year-old seedlings as materials to make cuttings, the bases of the cuttings were treated with the mixed solution of IBA, NAA, THB and soaked for 10 min. Furthermore, cuttings treated with water for the same duration were taken as the control (CK). After cutting for 75 days, we determined the callus rate, rooting rate, root index and root effect index of the cuttings of each treatment. Meanwhile, the formation process of the adventitious roots of cuttings from semi-woody branches of rejuvenated Q. texana was anatomically observed with the paraffin section technique.【Result】 Hormone treatments could significantly improve the rooting effect of Q. texana cuttings, and the results showed that the rooting rates of the treatment groups were higher than that of the control group in both the rejuvenated and six-year-old cuttings, with the highest rooting rate reaching 43.3%. The two-factor analysis indicated that the rejuvenation treatment was a crucial factor affecting the rooting of Q. texana cuttings. Additionally, through the comprehensive analysis and ranking of various indicators, we found that the rooting effect of the rejuvenated cuttings was better than that of the six-year-old cuttings. The anatomical structure of the stem during the rooting process of Q. texana was observed with the paraffin section method, and it was found that the stem of new cuttings did not contain latent primordia, which belonged to the induced root primordium rooting type. Callus and skin rooting existed, which were classified into the mixed rooting type. Moreover, anatomical observation found that the phloem of the stem contained continuous annular thick-walled tissue, which hindered adventitious root elongation.【Conclusion】 The best rooting effect of the cuttings was achieved when the cuttings were made from rejuvenated Q. texana seedlings, with the base part soaked in the IBA (500 mg/L),NAA (250 mg/L) and THB (50 mg/L) mixed solution for 10 min. Anatomical observation of the stem during the rooting process revealed that the stem did not contain latent root primordia, which belonged to the type of induced primordium rooting. The presence of annular continuous phloem fibers (thick-walled tissue) in the phloem is one of the reasons for rooting difficulty. There are two pathways in which adventitious root primordia can occur: one is through the emergence of adventitious root primordia from the callus, and the other is through cells that divide near the cambia to form root primordia. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Seasonal variations in photosynthetic efficiency and antioxidant characteristics of the current and one year-old leaves in Torreya grandis‘Merrillii’ ZHAO Xiaolong, SHEN Jiayi, LIU Tao, WU Jiasheng, HU Yuanyuan JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 45-50.   DOI: 10.12302/j.issn.1000-2006.202204017 Abstract （3512）   HTML （234）    PDF（pc） （1956KB）（1400）       Knowledge map    Save 【Objective】 Determination of seasonal changes in chlorophyll fluorescence parameters, antioxidant enzymes, malondialdehyde (MDA) and other parameters in current and 1 year-old leaves of Torreya grandis ‘Merrillii’ was to study the adaptive mechanism of the photosynthetic characteristics of T. grandis ‘Merrillii’ leaves to temperature changes during season. 【Method】 The chlorophyll fluorescence parameters, specific leaf weight (SLW), antioxidant enzyme activity and soluble protein changes of T. grandis ‘Merrillii’ leaves were measured in May, June, August, November and January of the second year. 【Result】 (1) Compared with mid-May, ΦPSⅡ of T. grandis ‘Merrillii’ leaves in mid-August was significantly up-regulated, while ΦNPQ was significantly down-regulated, and ΦNOwith little change. SOD and CAT activities in T. grandis ‘Merrilli’ current leaves were significantly increased, POD activity was significantly decreased, and MDA with little change.(2) Compared with mid-November, the average temperature in January of the second year decreased by nearly 10 ℃. ΦPSⅡ and ΦNPQ of T. grandis ‘Merrillii’ current leaves and one-year old leaves decreased significantly, while their ΦNOand MDA content increased significantly. 【Conclusion】 Compared with mid-May, T. grandis ‘Merrillii’ current leaves and one-year old leaves markedly improved ΦPSⅡ in mid-August is due to the high temperature and its leaves to absorb more light, and used for electron transfer, less dissipation of energy in the form of heat, the photosynthetic photoinhibition not occurring, its strong antioxidant enzyme system can coordinate to help them adapt to the high temperature specular environment. Compared with mid-November, T. grandis ‘Merrillii’ current leaves and one-year old leaves suffered cold damage during overwintering in mid-January of the second year, and the photosynthetic organs of leaves suffered light damage. Above all, T. grandis ‘Merrillii’ leaves are resistant to heat weather but not to cold weather, which may be the limiting factor of northern expansion. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Dynamic change of wetland landscape in Changsha based on JRC global surface water data ZENG Zheli, SHE Jiyun, TANG Zichao, LUO Chuying JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 9-18.   DOI: 10.12302/j.issn.1000-2006.202303019 Abstract （3510）   HTML （283）    PDF（pc） （3507KB）（1377）       Knowledge map    Save 【Objective】 The objectives of this study were to explore the temporal and spatial evolutions of wetland landscape in Changsha from 1999 to 2019, to comprehensively analyze the dynamic-change characteristics of wetland-landscape patterns in Changsha in the same period, and to explore the influence mechanism of natural and human factors on wetland-landscape patterns, so as to provide an important theoretical basis for the protection and rational utilization of wetlands in Changsha. 【Method】 Based on global surface water data (GSWD), combined with meteorological and hydrological data, this paper adopted the methods of wetland distribution information extraction, wetland type classification and landscape pattern index, aiming to achieve long-term and continuous monitoring of the dynamic evolution of annual wetland-landscape patterns in Changsha City from 1999 to 2019 based on the seasonal and fluctuating characteristics of wetlands. In addition, we analyzed the evolution trend of its long time scale, as well as the short-term fluctuation change characteristics. 【Result】 (1) Since 1999, the wetland area in Changsha has been overall increase, with permanent river being the main wetland type. From 2007 to 2009, there was a large fluctuation in wetland landscape, as represented by the transformation of permanent rivers and lakes to seasonal rivers and lakes, respectively, in the early stage, and by the reversal of fragmentation after 2008. The fragmentation degree of wetland-landscape pattern in Changsha continuously intensified until 2017 and later began to gradually recover. (2) The wetland-landscape pattern in Changsha was greatly affected by the natural factors such as precipitation and runoff from the Xiangjiang River and extreme freezing disasters that led to large fluctuations of the wetland-landscape pattern. The wetland landscape pattern in Changsha was also affected by human factors such as growing population and urban expansion that may lead to the intensification, but government policies and measures had a positive effect on wetland restoration. 【Conclusion】 It was feasible to use GSWD to extract wetland information. The wetland area in Changsha had continued to grow, among which permanent river was the main wetland type. The results from this study could provide important scientific references for the protection and rational utilization of wetlands in Changsha. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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The optimization of ecological spatial network in Jiuquan City based on the evaluation of ecological environment quality QIU Shi, YU Qiang, LIU Hongjun, WANG Huiyuan, LI Song, YUE Depeng JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 199-208.   DOI: 10.12302/j.issn.1000-2006.202204070 Abstract （3498）   HTML （162）    PDF（pc） （3686KB）（1214）       Knowledge map    Save 【Objective】 The objective of this study is to construct and optimize the ecological spatial network in Jiuquan City, aiming to enhance the quality of the ecological environment, harness regional ecological functions, and prevent desert expansion. 【Method】 By integrating remote sensing ecological index (RSEI) with the ecological spatial network, this study assessed the spatial pattern of landscape in Jiuquan City. By using complex network theory, the study identified weak ecological source areas and proposed optimization strategies. 【Result】 (1) The RSEI exhibited a spatial pattern in the Jiuquan City, with low values in the northern region and high values in the central and southern regions. (2) The potential ecological spatial network in Jiuquan City comprised 332 ecological nodes and 656 ecological corridors. Through the simulation of additional edges based on the region with the lowest RSEI, 242 edges were added, resulting in the inclusion of nine ecological stepping stones. (3) After the addition of edges, there was a noticeable improvement in the robustness of network nodes and connections, while the improvement in edge robustness was slight and not significant. 【Conclusion】 The optimization strategies of adding edges and stepping stones to weak ecological areas can enhance the stability and ecological restoration capacity of the ecological spatial network in Jiuquan City. The construction of new ecological corridors to enhance connectivity between source areas would facilitate regional ecological benefits and provide strategies for future ecological engineering projects in Jiuquan City. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Landscape pattern evolution and driving factors of Songhua River wetland in Harbin ZHAO Zhiqiang, XU Xiaolong, YUAN Qing, WU Yan JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 219-226.   DOI: 10.12302/j.issn.1000-2006.202301009 Abstract （3477）   HTML （164）    PDF（pc） （1932KB）（1448）       Knowledge map    Save 【Objective】 The Songhua River wetland is the most important ecosystem barrier in Harbin. This paper quantitatively studied the evolution and main influencing factors of the landscape pattern of the Songhua River wetland ecosystem in Harbin over the past 20 years, and we aim to provide a reference for wetland planning. 【Method】 Choosing the Harbin basin and its surrounding ecological area as the research object, Landsat remote sensing images from 2000, 2005, 2010, 2015 and 2020 were processed with the help of the GIS platform. The Fragstats software was used to analyze the regional landscape pattern index and explore the spatio-temporal evolution characteristics of the landscape pattern. Finally, SPSS was used for the statistical analysis of the factors affecting landscape pattern. 【Result】 (1) From 2000 to 2020, the water area (including wetland) continuously increased, while the cultivated-land area continuously decreased, which was the primary change feature of landscape pattern in the study area. The decreasing cultivated land was the main contributing factor of increasing water area, grassland, construction land, forest land and other land areas at 343.142 1, 2.484 9, 94.041 9, 35.469 0 and 1.980 0 km2, respectively; among them, the growth rate of water area, grassland, forest area and other land area exceeded 100%, and the area expansion showed an upward trend. (2) From the perspective of plaque types, the degree of fragmentation of each plaque increased to varying degrees during the 20 years, and the wetland landscape type structure tended to be complicated. From the landscape-level perspective, the overall landscape richness has increased, but the connectivity was poor, and the degree of external interference was relatively significant. (3) Urban economic development, climate and industrial structure were the main driving factors to stimulate the change of landscape pattern of the Songhua River wetland in Harbin. With the establishment of the Songbei District and the rise of tourism, relevant infrastructure has crowded the space of some water areas (including wetlands) along the river; wetland marshes and cultivated land have been divided into numerous patches, the overall landscape pattern tends to be fragmented, and human drivers have gradually become the dominant factors. 【Conclusion】 The landscape type of the Songhua River wetland in Harbin is a complicated structure. As human influence factors become more profound, the fragmentation degree of water patches increases, there is a serious loss of cultivated-land area, and the contradiction between cultivated-land protection and ecological protection remains prominent. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Professor Cheng Wan-chun and Dendrology FANG Yanming JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (3): 2-13.   DOI: 10.12302/j.issn.1000-2006.202404034 Abstract （3389）   HTML （316）    PDF（pc） （3315KB）（5166）       Knowledge map    Save As a distinguished dendrologist, forester, and forestry educator, Professor Cheng Wan-chun (1904-1983) devoted his life to the pursuit of dendrology science and education. As a learner of dendrology, he was diligent and eager to learn, lucky to meet good tutors, and had a well-rounded approach to his studies. As a dendrologist, he specialized in tree classification, focusing on gymnosperms, and expanding his academic boundaries from dendrology to forest geography. As a teacher of dendrology, he advocated cultivating virtue and talent, emphasized the cultivation of practical abilities, and implemented the feedback of scientific research in teaching. Professor Cheng Wan-chun regarded forest areas as the best laboratory of dendrology and personally visited forest areas such as West Tianmu Mountain in Zhejiang, Western Sichuan, and Lichuan in Hubei, collecting a large number of plant specimens, including types. Professor Cheng Wan-chun made many contributions to dendrology, discovering and naming one new family, five new genera, and 139 new species (including varieties). The most important contribution was the discovery of Metasequoia and the proposal of a classification system for gymnosperms. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Extraction of aquatic vegetation in Hongze Lake National Wetland Park based on Sentinel-1 and Sentinel-2 images HAN Sen, RUAN Renzong, FU Qiaoni, XU Hanwei, HENG Xuebiao JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 19-26.   DOI: 10.12302/j.issn.1000-2006.202212016 Abstract （3387）   HTML （275）    PDF（pc） （3960KB）（1892）       Knowledge map    Save 【Objective】 The objective of this study was to explore the extraction of spatio-temporal distribution of aquatic vegetation in lake wetlands using Sentinel-1 and Sentinel-2 data. 【Method】 Hongze Lake National Wetland Park was chosen as the research area. Based on the combination of Sentinel-2 MSI images and Sentinel-1 SAR images, the object-oriented image analysis was used. The feature set was constructed by using EVSI, NDVI, SR feature index and contextual features between objects, as well as differences in the backscatter coefficients of the SAR images corresponding to differences in the height of the emergent vegetation types. A decision-tree model was established at the object level to classify the wetland, and the spatio-temporal distribution of the aquatic vegetation and the emergent vegetation in the Hongze Lake National Wetland Park was acquired. 【Result】 The classification accuracy and the Kappa coefficient of aquatic vegetation were observed to be 89% and 0.85, respectively, and that of the emergent vegetation was 85.2% and 0.76, respectively. The results showed that, compared with the results of the pixel-based analysis method, the accuracy of object-based image analysis was higher. The wetland aquatic vegetation was dominated by submerged and emergent vegetation; among the emergent vegetation, lotus leaves and reeds were dominant. 【Conclusion】 The methods proposed in this study were feasible, and the results could provide a scientific basis for managers and planners of wetlands. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Changes in pigment and coloration mechanism of leaves during the discoloration period of Pistacia chinensis XU Zhizhao, YANG Xiuyun, WANG Yichen, DU Shuhui JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 97-104.   DOI: 10.12302/j.issn.1000-2006.202210034 Abstract （3373）   HTML （197）    PDF（pc） （2215KB）（2582）       Knowledge map    Save 【Objective】 The changes of physiological substances related to the discoloration period of the leaves of Pistacia chinensis in autumn were studied to reveal the regularity between leaf color and content.【Method】 The experiment was conducted to quantify and analyze the changes in leaf color parameters, pigments, osmotic substances, total nitrogen and phosphorus contents and the key enzyme activities of P. chinensis.【Result】 During the discoloration period, the contents of chlorophyll and carotenoid in leaves continuously decreased, the content of anthocyanins increased, and the leaves turned red. Anthocyanins in the leaves of P. chinensis showed extremely significantly positive correlations with a* values, the ratio of carotenoid to chlorophyll and anthocyanin to chlorophyll, soluble sugar, free amino acid, phenylalanine ammonialyase(PAL) and anthocyanidin synthase(ANS) (P<0.01). Anthocyanins were positively correlated with dihydroflavonol-4-reductase(DFR) (P<0.05). Anthocyanins were negatively correlated with nitrogen(N) (P<0.05). Anthocyanins were extremely significantly negatively correlated with phosphorus(P) (P<0.01). 【Conclusion】 The anthocyanin/chlorophyll ratio and anthocyanin content in the leaves during the autumn discoloration period of P. chinensis are the material basis for leaf reddening in the middle stage of discoloration. Soluble sugar content and PAL enzyme activity are the key factors affecting color. Mineral elements (nitrogen and phosphorus) content in the discoloration period was significantly reduced, promoting anthocyanin synthesis and affecting leaf color. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Community classification, structures and species diversity characteristics of Pinus massoniana and P. hwangshanensis in the eastern China FAN Mingyang, HU Meng, YNAG Yuan, FANG Yanming JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (1): 47-58.   DOI: 10.12302/j.issn.1000-2006.202210029 Abstract （3313）   HTML （86）    PDF（pc） （2167KB）（3860）       Knowledge map    Save 【Objective】 Pinus massoniana is the main coniferous tree species in subtropical China and P. hwangshanensis is the main constructive species in subtropical mid-montane region of the eastern China. Both species coexist at horizontal level but exhibit distinct vertical distributions. The objective of this study is to investigate the distribution patterns of P. massoniana and P. hwangshanensis forests and provide a theoretical basis for the scientific management and conservation of these forest resources. 【Method】 The study was focused on eight typical distribution areas in the eastern subtropical region of China. Non-metric multidimensional scaling analysis (NMDS) and multivariate regression trees (MRT) were employed to explore the differences in community structure and the main influencing factors between the two pine forests. Additionally, a linear mixed-effects model was used to quantify the response of species diversity indices to abiotic factors. Based on the principles for compiling the Vegegraphy of China, a preliminary quantitative classification of P. massoniana and P. hwangshanensis forests was performed. 【Result】 Significant differences were observed in the community structures of P. massoniana and P. hwangshanensis forests, with elevation identified as the primary influencing factor. Mean annual temperature had a significant effect on species richness within both communities, while mean annual precipitation had the most pronounced impact on overall species richness. Elevation exerted a significant influence on the evenness of the two communities. The preliminary vegetation classification resulted in the identification of six associations for P. massoniana forest and five associations for P. hwangshanensis forest. 【Conclusion】 Altitude variations shape the differences in community structure between P. massoniana and P. hwangshanensis forests and directly or indirectly influence species diversity in these communities. The vegetation classification highlights the diversification of vegetation types in the two pine forests and provides a reference for future classification efforts. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Alkali stress tolerance analysis of four Rhododendron cultivars GONG Rui, XIA Xi, ZHANG Chunying JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 113-120.   DOI: 10.12302/j.issn.1000-2006.202207014 Abstract （3298）   HTML （177）    PDF（pc） （2942KB）（1487）       Knowledge map    Save 【Objective】 This study aims to analyze the tolerance differences of Rhododendron cultivars to alkali stress and effects on accumulation and distribution of mineral elements in different organs of rhododendron, and investigate the response mechanism of rhododendron to alkali stress. The results of this study provide a theoretical basis for breeding alkali-tolerant varieties. 【Method】 Alkaline salt solution Na2CO3-NaHCO3 (volumn fraction 1∶9) was used to adjust the pH value of deionized water to 7.52 and 9.14, respectively. Four Rhododendron cultivars (Rhododendron ‘Zihe’, R. ‘Kirin’, R. ‘Yanzhi Mi’ and R. ‘Fenxiu’) were treated with pot watering of alkaline solution for two months, and the growth of plants, as well as physiological and biochemical indexes such as chlorophyll content, root vigor, ferric reductase activity and mineral content were measured. 【Result】 The different varieties of Rhododendron were significantly different in terms of their tolerance to alkali stress. Those plants with weak resistance showed symptoms of alkali damage, such as the yellowing of leaves or leaves drying and falling off, root blackening and even death. With an increase in alkaline stress, the high increment and dry matter ratio of the different varieties decreased significantly. The analysis of plant dry matter quality showed that the dry matter quality of the underground part of R. ‘Kirin’ and R. ‘Yanzhi Mi’ decreased significantly with the increasing degree of alkali stress; R. ‘Zihe’ significantly decreased under high alkali stress, and R. ‘Fenxiu’ had no significant difference among different treatments. The chlorophyll content and root activity of rhododendron decreased significantly, and root iron reductase activity increased. The root activity of R. ‘Zihe’ and R. ‘Fenxiu’ showed no significantly difference under different alkali intensities, while the root activity of R. ‘Kirin’ and R. ‘Yanzhi Mi’ significantly decreased compared with the control. Only R. ‘Zihe’ showed significantly higher root iron reductase activity than the control under high alkali stress, whereas the other three cultivars showed no significantly difference among different treatments. An increase in alkali stress affected the accumulation and distribution of different mineral elements in the rhododendron. Na and Fe ions content significantly accumulated in the root system, whereas K+ and Ca2+ were concentrated in the leaves, and the content decreased significantly. The content of Na+ in the leaves varied among cultivars. After alkali stress treatment, the content of Na+ in leaves of R. ‘Yanzhi Mi’ and R. ‘Kirin’ increased significantly, but there was no significant change in R. ‘Zihe’ and R. ‘Fenxiu. ’ 【Conclusion】 Based on the above indexes, R. ‘Zihe’ and R. ‘Fenxiu’ had strong alkali resistance, followed by R. ‘Yanzhi Mi’, and the alkali resistance of R. ‘Kirin’ was weak. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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Effects of H2S donor NaHS on the adaptability and antioxidant properties of Agave americana plantlets under an in vitro culture of osmotic stress SHEN Yang, DI Jingjing, CHEN Ying, FENG Kai, LU Jinling, HU Yuchen JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 121-128.   DOI: 10.12302/j.issn.1000-2006.202305030 Abstract （3285）   HTML （183）    PDF（pc） （2127KB）（974）       Knowledge map    Save 【Objective】 Agave americana is an important crassulacean acid metabolism (CAM) plant with high economic value in tropical areas. Studying its drought adaptability could provide evidence of the drought tolerance mechanism, and support for resource development and engineering research regarding the utilization of CAM plants. 【Method】 In this study, A. americana plantlets were treated with 1.0 mmol/L NaHS (NS), 10% polyethylene glycol (PEG10), 20% PEG (PEG20), 1.0 mmol/L NaHS+10% PEG (NS+PEG10), and 1.0 mmol/L NaHS+20% PEG (NS+PEG20) under an in vitro culture. The responses to PEG osmotic stress were studied and the effects of H2S donor NaHS on osmotic regulation and antioxidant properties in A. americana were investigated. 【Result】 The results showed that the A. americana plantlets could survive under the 20% PEG (high concentration) treatment and had a degree of drought resistance. However, injury symptoms and oxidative stress reactions occurred, with the fresh mass decreasing by 16.6% in PEG20. The cell ultrastructure changed, and the malondialdehyde (MDA) and H2O2 contents increased in PEG20. Despite this, the plantlets regulated osmotic pressure and reduced the stress intensity by increasing the levels of proline and soluble sugars. In the presence of PEG, H2S donor NaHS could reduce the excessive accumulation of proline and H2O2. Furthermore, H2S could activate superoxide dismutase (SOD) and five antioxidases, and increased the glutathione (GSH) content to clear active oxygen species (ROS) and active carbonyl compounds, subsequently enhancing the antioxidant capacity. 【Conclusion】 The A. americana plantlets had a certain degree of drought tolerance. The H2S had an important role in osmotic regulation and regulating antioxidant levels, making the plantlets better adapted to drought conditions. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Effects of fertilization application on quantity and quality recovery of restoring strip-harvested moso (Phyllostachys edulis) bamboo forests LI Chengji, GUAN Fengying, ZHOU Xiao, ZHANG Xuan, ZHENG Yaxiong JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 79-85.   DOI: 10.12302/j.issn.1000-2006.202209048 Abstract （3266）   HTML （201）    PDF（pc） （1632KB）（1178）       Knowledge map    Save 【Objective】 Moso bamboo (Phyllostachys edulis) is an integral part of China's forest resources, and strip harvesting is an efficient and mechanizable novel bamboo forest management mode. This study aimed to investigate the promotion effect of proportional fertilization on the post-harvesting recovery of forest stands and select the most suitable fertilizer ratio, providing a reference for the efficient and sustainable management of moso bamboo forests.【Method】 In the state-owned Yixing Forest Farm, in selecting the area with favorable site conditions, we selected a pure stand of old-growth moso bamboo and set up a fertilization experiment with three fertilization mass ratios of N to P2O5 to K2O is 2.0∶1.0∶1.0, 3.5∶1.0∶2.0 and 5.0∶1.0∶2.5 (F1, F2 and F3, respectively) after strip harvesting with an 8-m bandwidth. The main productivity indicators of the forest land [such as the number of shoots, percentage of mature bamboo trees, diameter at breast height (DBH) characteristics of the new bamboo] were investigated and explored the response mechanism of the quality and quantity characteristics of standing bamboo to fertilization during the restoration process of strip-cutting moso bamboo forests through data comparison, variance analysis, linear relationship fitting, and other pertinent statistical methods.【Result】 (1)Fertilization could significantly induced new shoot emergence, but the phenomenon of shoot retreat within the stand was evident, the stand splitting rate was significantly reduced, and the stand density of the fertilization treatment did not significantly different from that of the control treatment, indicated that the quantitative characteristics of the stand returned to the pre-harvesting level;(2)The F2 and F3 treatments were able to significantly increase the average DBH of the new bamboo and the proportion of medium- and large-diameter bamboo trees. The diameter at breast height-height (DBH-H) scatter relationship of the new bamboo in the F2 treatment was close to that of the traditional management model, indicating that the qualitative characteristics of the stand were significantly improved. 【Conclusion】 The quantitative and qualitative characteristics of moso bamboo stands recovered by strip harvesting varied in response to different fertilizer ratios, but the quantitative characteristics could be restored to pre-harvesting levels, and the quality characteristics could be significantly improved by high N and K fertilizer ratios, with the most profound effect being induced by an mass ratio of N to P2O5 to K2O is 3.5∶1.0∶2.0. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Construction of molecular ID for Osmanthus fragrans cultivars based on phenotypic traits and single nucleotide polymorphisms (SNPs) WANG Yihan, LIU Jiaojiao, JIN Peiquan, LI Shuqing, WEI Jianfen, GUO Peng, SHANG Fude JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (4): 12-24.   DOI: 10.12302/j.issn.1000-2006.202405026 Abstract （3245）   HTML （225）    PDF（pc） （5559KB）（1221）       Knowledge map    Save 【Objective】This study selected core genomic single-nucleotide polymorphism (SNP) loci to establish a rapid SNP genotyping method on the KASP platform, and to construct molecular IDs for Osmanthus fragrans cultivars. This study provides a theoretical foundation for identifying, tracing and protecting the intellectual property of O. fragrans cultivars.【Method】Field surveys were conducted to investigate key phenotypic characteristics of O. fragrans cultivars. Following two rounds of rigorous screening, we identified a set of core SNP markers capable of completely distinguishing previously sequenced cultivars. Subsequently, we analyzed the polymorphic information content (PIC) and expected heterozygosity (He) of each SNP locus. Using the genome sequences of ‘Rixianggui’ as a reference, species-specific KASP primers were designed for PCR amplification. Based on the genotyping results, we constructed cultivar DNA fingerprints and assessed the efficiency of core SNP markers for cultivar identification. Molecular IDs for O. fragrans cultivars were established by integrating phenotypic information codes with molecular fingerprint codes.【Result】We retained a total of 14 core SNP loci from genomic SNPs that fully discriminated the sequenced cultivars. The PIC values of these loci ranged from 0.246 to 0.375, with an average of 0.335, and the He indices ranged from 0.288 to 0.500, averaging 0.431. The KASP primers designed for these core SNP loci produced accurate genotyping results, enabling us to construct DNA fingerprints capable of distinguishing all 90 tested cultivars, including those not previously sequenced. Each cultivar was assigned a molecular ID composed of 34 digits.【Conclusion】In conclusion, 14 core SNP loci (SNP1 to SNP14) were identified that effectively discriminate among at least 90 O. fragrans cultivars. Unique molecular ID codes were constructed using DNA fingerprint codes along with serial codes derived from cultivar group types and phenotypic characteristics. Finally, barcode and quick response (QR) codes were generated for each cultivar. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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The effects of intercropping of Carya illinoinensis and Camellia sinensis ‘Anjibaicha’ on photosynthetic characteristics of C. sinensis tree during rapid growth period TIAN Mengyang, ZHU Shulin, DOU Quanqin, JI Yanhong JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 86-96.   DOI: 10.12302/j.issn.1000-2006.202208022 Abstract （3234）   HTML （202）    PDF（pc） （3031KB）（1713）       Knowledge map    Save 【Objective】 This article explores the differences in photosynthetic and fluorescence characteristics of Camellia sinensis ‘Anjibaicha’ at different measuring points of Carya illinoinensis-Camellia sinensis intercropping to provide a theoretical basis for high-efficiency compound cultivation of Carya illinoinensis-Camellia sinensis ‘Anjibaicha’.【Method】 In this compound model, the daily change in photosynthetic rate, light-response curves, fluorescence parameters and chlorophyll content of 10-year-old Camellia sinensis ‘Anjibaicha’ trees were measured in the fast-growing period (July-September) at four measuring points, i.e., under-crown (T1), crown-margin (T2), outside-crown (T3), and single Camellia sinensis comparison (T0).【Result】 The net photosynthetic rate(Pn) of Camellia sinensis ‘Anjibaicha’ could be significantly altered in T2. The Pn values at T1, T2 and T3 were significantly higher than those at T0 in July under high temperatures. The leaves had a midday depression of photosynthesis at T0 in August, and the Pn at T2 was significantly higher than that at T0. The Pn at different measuring points (T1, T2 and T3) were significantly higher than those of T0 in September. Compared with the control (T0), the higher apparent quantum efficiency (ηAQY), maximum net photosynthetic rate ( {P_{\mathrm{n}}}_{,\mathrm{m}\mathrm{a}\mathrm{x}}), and light saturation point (PLSP) were high, and the light compensation point (PLCP) was low at T2. The dark respiration rate (Rd) gradually decreased with decreasing light intensity. From July to September, the chlorophyll content of Camellia sinensis leaves was significantly higher in intercropping than in single Camellia sinensis cropping. With the decrease in light intensity, chlorophyll a (Chla), chlorophyll b (Chlb), and total chlorophyll (Chl) gradually increased, and the chlorophyll a/b value showed a decreasing trend. Camellia sinensis leaves produce more chlorophyll, which helps Camellia sinensis trees capture more light energy for photosynthesis. The maximum photochemical efficiency (FV/Fm) and potential photochemical activity (FV/F0) of PSⅡ of Camellia sinensis trees in intercropping were significantly higher than those of single Camellia sinensis cropping in July and August. The light energy conversion efficiency and electron transfer ability of Camellia sinensis ‘Anjibaicha’ leaves in single cropping decreased because high temperature and high-intensity light could produce obvious photoinhibition. In September, the FV/Fm and FV/F0 of Camellia sinensis trees at T2 during intercropping were significantly higher than those of T1 and T0. The results showed that excessive shading inhibited the photochemical activity of PSⅡ, which blocked energy transfer and transformation in photosynthesis. 【Conclusion】 In the Carya illinoinensis-Camellia sinensis ‘Anjibaicha’ forest compound model, many photosynthetic physiological indexes of Camellia sinensis ‘Anjibaicha’ were improved, among which the crown-margin (T2) environment was favorable for the photosynthesis of Camellia sinensis ‘Anjibaicha’ leaves, followed by the outside-crown (T3), and the under-crown (T1) and monoculture (T0) were poor. High temperature and high-intensity light have obvious photoinhibition in single-cropped Camellia sinensis ‘Anjibaicha’, which reduced photosynthetic efficiency. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Effect of stand density on radial growth-climate relationship of Larix gmelinii HAN Xinyu, GAO Lushuang, QIN Li, PANG Rongrong, LIU Mingqian, ZHU Yihong, TIAN Yiyu, ZHANG Jin JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 182-190.   DOI: 10.12302/j.issn.1000-2006.202209007 Abstract （3203）   HTML （169）    PDF（pc） （2250KB）（2166）       Knowledge map    Save 【Objective】 To develop a sustainable management plan for Larix gmelinii, which is influenced by climate change, it is crucial to understand the dynamic relationship between radial growth and climate in forests with different tree densities.【Method】 Based on the stand density index, nine plots with three density levels (low, middle, high) were established in the central and northern Greater Khingan Mountains. Tree cores of L. gmelinii were collected during a field investigation. The Mann-Kendall test method was used to determine the turning point of temperature in the study area. To examine the radial growth trend of L. gmelinii, negative exponential function detrending and a linear function fitting were applied. Then, a Pearson correlation and sliding correlation were used to analyze whether the relationship between the radial growth and climate factors under each stand density remained stable after the temperature turning point.【Result】 The radial growth of L. gmelinii displayed trends of both enhancement and decline after the temperature turning point. The proportion of declining trees increased with increasing stand density. The growth of L. gmelinii was strongly inhibited when the stand density was high. Its average growth change rate reached -25% during 1988-1990, indicating a serious growth decline. Instead, the L. gmelinii trees in low density plots maintained a 54% growth enhancement ratio. Stand density may also influence the response of L. gmelinii growth to climate. Under a high stand density, the L. gmelinii growth of the decline group was positively correlated with the standardized precipitation evapotranspiration index in August (P<0.05) and negatively correlated with summer temperature (P<0.05), but under a low stand density, the growth of L. gmelinii was positively correlated with temperature. With the warming and drying trend in the study area, the relationship between tree growth and temperature shifted from positive to negative with increasing stand density.【Conclusion】 The proportion of declining trees increased with increasing stand density after the significant change of temperature. The impact of water limitation on growth was alleviated at a low stand density, while the trees in high density plots were more sensitive to climate factors. Reducing the stand density could mitigate the negative impacts of climate warming on the growth of L. gmelinii. Therefore, adjusting stand density is a necessary management operation to slow the declining trend of L. gmelinii. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Response of physiological indexes of three Olea europaea cultivars to PEG stress DU Jincheng, LI Xinxin, WANG Zeliang, LIU Si, ZHONG Yi, WANG Lihua JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 137-143.   DOI: 10.12302/j.issn.1000-2006.202208063 Abstract （3165）   HTML （182）    PDF（pc） （5216KB）（1086）       Knowledge map    Save 【Objective】 The physiological and biochemical response characteristics of leaves under continuous drought stress in three main cultivars of Olea europaea (‘Arbeqina’‘Koroneiki’ and ‘Arbosana’) in the Sichuan Province were compared to provide a basis for the cultivation and introduction of excellent varieties of olive according to local conditions. 【Method】 Taking ‘Arbeqina’‘Koroneiki'and ‘Arbosana’ as the research objects, polyethylene glycol 6000 (PEG-6000) solutions with mass ratio of 5%, 10%, 15%, 20%, and 30% were used to simulate continuous drought stress for 35 days. The corresponding physiological indicators of the leaves were analyzed, measured, and evaluated.【Result】 Over time with the deepening of osmotic stress, the functional traits of leaves among the three oleifera cultivars displayed certain interspecific differences. At the same time, the peroxidase (POD) and superoxide dismutase (SOD) activities in the leaves of the three cultivars of olive oil displayed an increasing trend. Compared with the cultivars, over time with the deepening of osmotic stress, the chlorophyll content of ‘Koroneiki’ decreased slightly, the proline content increased significantly, and the POD and SOD activities in leaves increased significantly. 【Conclusion】 The leaf function traits of the three olive varieties under different levels of continuous drought stress varied greatly, displaying different adaptive characteristics. Among the three varieties, the leaf function traits followed the order of ‘Koroneiki’>‘Arbosana’>‘Arbeqina’. Among the tested olive varieties, ‘Koroneiki’ had a strong osmotic adjustment ability and antioxidant capacity, and a strong adaptability to drought stress, being superior to ‘Arbosana’ and ‘Arbeqina’. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Dehaze algorithm for woodland UAV images based on Resnet NIU Hongjian, LIU Wenping, CHEN Riqiang, ZONG Shixiang, LUO Youqing JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 175-181.   DOI: 10.12302/j.issn.1000-2006.202203011 Abstract （3144）   HTML （167）    PDF（pc） （3334KB）（1144）       Knowledge map    Save 【Objective】 Aiming to address the phenomena of low contrast, low saturation, and hue shift in unmanned aerial vehicle (UAV) photography images of forestland under hazy conditions, this study proposes a de-fogging method for UAV images adapted to forestland aerial photography scenes based on Resnet. 【Method】 The UAV images in woodland scenes were characterized by texture features and rich high-and low-frequency information. GFF information transfer modules were attached to each layer of the backbone network to transform feature maps into weight maps for filtering and sending to other layers, and thresholds were set at the receiving end to avoid the adverse effects of redundant information. Then, the global defogging effect was enhanced by dense links to improve the defogging quality in high- and low-frequency image regions. Finally, defogging experiments were conducted on a test set of woodland UAV images with fog. 【Result】 The average structural similarity of DHnet on the test set of woodland images was 0.83, and the average peak signal-to-noise ratio was 22.3 dB, which represented improvements of 4.8% and 39.3%, respectively, compared with the Resnet method. 【Conclusion】 The algorithm can effectively reduce tonal shift and remove residual fog, improving the color fidelity and detailed information retention of aerial woodland fog images obtained by UAV photography. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited:

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Prunus discoidea‘Yuanchun’:a new cultivar of cherry blossom YANG Hong, YI Xiangui, WANG Xianrong, WU Tong, ZHOU Huajin, CHEN Jie, LI Meng, ZHU Zhaoqing JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (2): 275-276.   DOI: 10.12302/j.issn.1000-2006.202209044 Abstract （3087）   HTML （159）    PDF（pc） （1685KB）（809）       Knowledge map    Save Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0）

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A review on the taxonomy study of Prunus subgen. Cerasus (Mill) A. Gray YI Xiangui, LI Meng, WANG Xianrong JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (3): 46-57.   DOI: 10.12302/j.issn.1000-2006.202405008 Abstract （3044）   HTML （224）    PDF（pc） （1729KB）（4481）       Knowledge map    Save Reviewed and summarized the research history of the taxonomy of the subgenus Prunus subgen. Cerasus, provided an overview of major classification systems of the subgen. Cerasus. Summarized the advances in experimental taxonomy studies on the subgen. Cerasus, It is found that morphological markers play an important role in the classification of subgen. Cerasus. SSR marker studies can provide evidence for discussions on interspecific and intraspecific relationships within the subgen. Cerasus, DNA sequence markers have made important achievements in the study of subgen. Cerasus classification, essentially clarifying the phylogenetic relationships within the subgen. Cerasus. Integrated the latest data on phylogeny and geographic distribution of the subgen. Cerasus, outlined the main framework of the phylogeny of the subgen. Cerasus, speculation that the origin of this subgenus is from the Himalayan region to southwestern China or the Mediterranean region, summarized the main migration routes of the subgen. Cerasus. By combining literature and specimen data, field surveys and recent research conclusions, a total of 76 species of the subgen. Cerasus (including 11 varieties) were listed in the world species catalog, and statistical analysis was conducted on the main distribution areas and groups of the subgen. Cerasus; proposed classification viewpoints for the P. serrulata complex, P. subhirtella complex, and other controversial groups. A comprehensive analysis of the status of the taxonomy of the subgen. Cerasus, suggesting that more in depth research is needed on the complex and controversial groups within the subgen. Cerasus, as well as resource surveys and classification in the central and western regions; exploring combinations of multiple species, populations, and omics at a large scale is an important direction for the taxonomy research of the subgen. Cerasus. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments（0） Cited:

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Soil quality assessment for Carya illinoensis-Paeonia ostii under various patterns CHEN Hui, WANG Gaiping, PENG Fangren, ZHU Yunfen, ZHANG Yu, WANG Han JOURNAL OF NANJING FORESTRY UNIVERSITY    2024, 48 (4): 177-183.   DOI: 10.12302/j.issn.1000-2006.202210021 Abstract （2940）   HTML （104）    PDF（pc） （1822KB）（792）       Knowledge map    Save 【Objective】The aim of the present study was to investigate the soil physical properties, chemical properties, and enzyme activities under different Carya illinoensis ‘Pawnee’ and Paeonia ostii ‘Feng Dan’ planting modes, as well as analyze the effects of different modes and seasons on soil characteristics.【Method】The treatments included single cultivation of C. illinoensis (mode Ⅰ), compound cultivation of C. illinoensis ‘Pawnee’-P. ostii ‘Feng Dan’ (mode Ⅱ), and single cultivation of P. ostii (mode Ⅲ). Seasonal variation of soil physical properties, chemical properties, and enzyme activities were measured under different modes, and the minimum date set method and soil integrated fertility index (IFI) were utilized to evaluate the changes of soil fertility.【Result】The nutrient and enzyme activity in the surface soil were higher than those in the deep soil. The soil moisture content and bulk density gradually varied with the seasons of spring, summer and autumn. There was no significant difference on soil pH between the spring and summer seasons, and the lowest soil pH was observed in autumn. The soil catalase activity in summer was higher than that in spring and autumn. The soil organic matter content, total nitrogen content, available potassium content, sucrase activity, and urease activity increased during the seasonal variation of spring, summer, and autumn. In mode Ⅲ, the soil available phosphorus content in autumn was higher than that in spring and summer. The seasonal variation of the soil IFI was the lowest in summer and highest in mode Ⅱ.【Conclusion】There is a correlation among soil physical properties, chemical properties and enzyme activities. The soil fertility of the compound cultivation of C. illinoensis ‘Pawnee’-P. ostii ‘Feng Dan’ (mode Ⅱ) is significantly higher than single cultivation of either species, and the soil fertility quality is lower in summer than in spring and autumn. The soil fertility quality is directly affected by bulk density, total nitrogen content, available potassium content, available phosphorus content, sucrase activity, and urease activity. Further, sucrase activity is more sensitive in evaluating the soil IFI in all seasons. Table and Figures | Reference | Related Articles | Metrics | Comments（0） Cited: