【Objective】 This study investigated the role of succession and regeneration for populations of Cyclocarya paliurus; in particular, seasonal dynamics of seed rain and soil seed bank characteristics were investigated.【Method】 Investigation of seasonal dynamics of seed rain was performed in plantations of C. paliurus with three densities (C1: 1 050 plant/hm2, C2: 720 plant/hm2, and C3: 525 plant/hm2), which were planted in Dashishan, Liyang, Jiangsu Province; the traits of seeds were also analyzed. In addition, we surveyed and dissected the soil seed banks dispersed in five natural populations located in Jiuling Mountain, Jiangxi Province. The soil seed banks in two layers, named as litter layer (Ⅰ) and soil layer (Ⅱ), were separately analyzed.【Result】 According to the density of seed rain, the duration of seed falling was divided into three stages: early stage (8.20-9.20), medium stage (9.20-12.10), and late stage (12.10-12.30); two peaks of seed rain were recorded at 9.10 and 12.20, respectively; the amount of seed rain during these two peaks in the early and late stage accounted for 42.4% and 43.5% of the whole annual production, respectively. The differences of seed rain and number of viable seeds at various stages were significant, but the other seed traits were insignificant. Moreover, the effects of plantation density on the number of full seeds and 1 000-seed weigh were significant, but no effect on the other seed traits was detected. In five natural populations of C. paliurus, the density of soil seed bank in the Ⅰ layer (37.4 grain/m2) was higher than that in the Ⅱ layer (17.9 grain/m2), and this parameter presented an obvious divergence among populations. Moreover, the seed diameter, thickness and volume from the Ⅱ layer were all smaller than those from the Ⅰ layer. More importantly, seed fullness and viability from the soil seed banks were lower by 13.0%-27.1% and 0%-10.4%, respectively. However, these indicators of seeds from the Ⅰ layer were generally higher those from the Ⅱ layer, indicating a descending tendency in seed quality as duration increases. 【Conclusion】 There were two peaks of seed rain in plantations of C. paliurus, and stand density affected the density of seed rain and 1 000-seed weigh more than seed fullness or viability. Both the quantity and quality of seeds in the soil banks from the Ⅰ layer were superior to those from the Ⅱ layer. The dormancy of seeds stored in soil is relieved in favor of regeneration and succession of C. paliurus populations.
【Objective】 To provide scientific references for germplasm conservation and development and utilization of Castanopsis carlesii, the geographical variations of seed morphological characteristics and nutrient content of C. carlesii from different provenances were analyzed. 【Method】 Seeds of C. carlesii were collected from 357 individuals growing in natural distribution areas of thirteen provenances. Six morphological characteristics (seed length, seed width, length width ratio, volume, surface area and 1 000-seed weight) and nutrients (soluble sugar and starch) of seeds were measured, and then variance, correlation and cluster analyses were conducted.【Result】 Seeds’ morphological characteristics were significantly different between and within provenances (P < 0.01); the mean values of seed length, width, length width ratio, volume, surface area and 1 000-seed weight ranged from 0.93-1.02 cm, 0.82-0.93 cm, 1.07-1.21, 0.32-0.46 cm3, 1.83-2.32 cm2 and 397.15-599.67 g, respectively. The nest analysis of variances showed that the maxima of seed length, width, volume, surface area, and 1 000-seed weight were observed in seeds from Jiangxi Dingnan (JXDN), and significantly differed from those from other provenances. The 1 000-seed weight of Anhui Qimen (AHQM) was 66.23% that of JXDN, and the seed length, width, volume and surface area were comparatively smaller. The percentages of starch and soluble sugar were 31.80% and 21.76%, respectively. The nutrient contents of C. carlesii were significantly different between provenances (P < 0.01); the coefficients of variation were 14.06% and 30.62%. The average coefficient of phenotypic differentiation was 28.15%, and genetic variation within provenances was the main source of the genetic variation of morphology characteristics. The correlation analysis showed that starch and 1 000-seed weight had the most positive correlations with seed width (P < 0.05), while sugar had an extremely significant correlation with seed length and length-width ratios (P < 0.01). Seed length showed a significant negative correlation with longitude (P < 0.05). The length-width ratio showed an extremely significant negative correlation to longitude (P < 0.01), and had significant negative correlation with precipitation during the coldest quarter (P < 0.05). The starch showed a significant correlation to annual mean temperature. The cluster analysis showed that the thirteen provenances could be divided into three groups. Group Ⅰ included JXDN, which possessed large sized seeds, high soluble sugar and high starch. Group Ⅱ included AHQM, Jiangxi Xinfeng (JXXF), Zhejiang Kaihua (ZJKH) and Guangdong Lianping (GDLP), which had small sized seeds, high soluble sugar and low starch groups; the other eight provenances fell into group Ⅲ, exhibiting medium sized seeds, and medium soluble sugar and starch contents. Adjacent provenances did not cluster together preferentially, indicating that there is no obvious geographical variation of C. carlesii.【Conclusion】 The phenotypic diversity of C. carlesii was the result of genetic and environmental factors. In addition, the variation in seeds was mainly influenced by longitude, annual mean temperature, and precipitation of the coldest quarter. The genetic variation within provenances was the main source of genetic variations of seed characteristics; therefore, the selection and utilization of superior individual plants should be strengthened in the genetic improvement of C. carlesii. JXDN has the characteristics of large seeds and high nutrition, and offers the potential for excellent provenances.
【Objective】 This study explored physiological and ecological mechanisms of seed vigor change in the canopy seed bank of Koelreuteria bipinnata in order to accurately understand the ecological significance of canopy seed banks.【Method】 A canopy seed bank of K. bipinnata was used as the object of study, and seeds were collected from the canopy seed bank at certain time intervals after fruits entered the ripening period. We then conducted a germination test and determined the seed dry mass, water content, malondialdehyde content, and activities of SOD, APX, CAT and DHAR. Finally, we performed an analysis between the germination percentage and physiological indices.【Result】 During the study duration, seeds in the canopy seed bank experienced four physiological periods, including physiological maturity, mature dehydration, dormancy induction and release. The seeds in each physiological period generally had the best germination under simulated autumn alternative temperatures, followed by spring alternative temperatures and summer alternative temperatures. The vigor of the seeds was maintained at a high level after mature dehydration was finished, and the four antioxidases played a significant positive role in the acquisition and maintenance of seed vigor, being significantly positive correlative with the germination percentages under simulated spring, summer and autumn alternative temperatures. Moreover, they all decreased with the induction of seed dormancy and increased with the release of dormancy, which also confirmed the “Embryo stress theory” of seed dormancy and germination.【Conclusion】 This study not only promotes further understanding of the canopy seed banks, but also finds that seeds in the canopy seed bank of K. bipinnata have a strong ability to maintain vigor. Full use of canopy seed banks in forest management and vegetation restoration should be encouraged.
【Objective】 In this study, experiments were carried out to explore the dynamic changes of nutrient contents, enzyme activities and endogenous hormones during the seed stratification of Phoebe sheareri. Additionally, this study was conducted to reveal the internal physiological mechanisms involved in seed dormancy and provide a theoretical basis for its dormancy release and germination. 【Method】 Fresh and full seeds of P. sheareri were treated with gibberellin and stratification was conducted; the physiological indicators during stratification were also determined. 【Result】 The seed dormancy of P. sheareri was relieved by stratification for 63 days. The germination rate of low temperature and variable temperature stratification was 85.83% and 72.75%, respectively. The initial starch content was 467.88 mg/g and decreased gradually during stratification. Soluble sugar, soluble protein and crude fat were decomposed to varying degrees. Under the two kinds of stratification treatments, the soluble sugar content in the seeds of P. sheareri changed greatly, from decreasing to increasing, and then decreasing again. The soluble protein content in P. sheareri seeds increased initially and then decreased under two stratification treatments. On the whole, the crude fat content in the seeds of P. sheareri showed a gradually decreasing trend under each stratification treatment. The activities of amylase, APA and POD were increased. This indicated that the two stratification treatments could promote the continuous activation of APA and POD activities. What’s more, endogenous hormones such as IAA, IPA, GA3 and ABA played an important role in the regulation of seed dormancy and germination. During the whole stratification process, the contents of IAA, IPA and GA3 increased, while the contents of ABA decreased, and the mass ratios of IAA/ABA, IPA/ABA and GA3/ABA increased. 【Conclusion】 There was medium dormancy in seeds of P. sheareri. Gibberellin and stratification could release dormancy, and cold stratification was better to accelerate seed germination. Starch was the main storage material in the seeds of P. sheareri. The transformation of nutrients and the coordination of endogenous hormones played an important role in the seeds dormancy release.
【Objective】 The microbial community in the rhizosphere is produced by the interactions of the soil environment and root metabolic activities, and plays an important role in plant growth and development. Analysis of characteristics of bacterial community in the rhizosphere soil of wild tree peony species possesses important theoretical significance for the effective use of microbial resources to protect wild plant germplasm resources and lays a foundation for improving the soil environment of wild tree peony species and realizing the broad-spectrum planting of high-quality germplasm resources. 【Method】 In the present study, MiSeq high-throughput sequencing technology with 16S rRNA genes was employed to investigate bacterial community characteristics in the rhizosphere soil of nine wild tree peony species (Paeonia ludlowii, P. potaninii, P. delavayi, P. lutea, P. rockii, P. ostii, P. decomposita, P. jishanensis and P. qiui) as well as their relevance with physicochemical properties. 【Result】A total of 606 536 sequences and 99 OTU clusters were obtained by high-throughput sequencing, which belonged to 24 phyla, 84 classes, 154 orders, 280 families and 603 genera. Alpha diversity analysis revealed that the rhizosphere microbial community of P. ostii contained the highest number of species. Beta analysis revealed that the bacterial community structures in the rhizosphere soils of P. decomposita, P. rockii, P. lutea, P. ostii, P. delavayi and P. ludlowii were similar. Analysis of bacterial community compositions showed that the core and dominant bacteria in the rhizosphere soil were Proteobacteria, Acidobacteria, Actinobacteria and Chloroflexi. Significant differences were found in beneficial bacteria among different wild tree species, such as Acidobacteria, Chloroflexi, Nitrospirae, Gemmatimonadetes, Nitrosospira and Pseudomonas. Predicted functions of the rhizosphere bacterial community have mostly focused on metabolism, genetic information processing, and environmental information processing. The bacterial community in the rhizosphere of wild peony trees is significantly affected by soil organic matter and available potassium. 【Conclusion】These results indicated that the bacterial community structure in the rhizosphere soil of different wild tree peony species was different, and the formation of a bacterial community was closely related to the varieties of tree peony. The enrichment in beneficial bacteria (genera) promoted plant growth. In the future, rhizospheric microbial resources could be effectively utilized to improve the soil environment of wild tree peonies, to realize the broad-spectrum planting of high-quality germplasm resources, and to lay the foundation for the protection of wild planting resources.
【Objective】 Paeonia×suffruticosa (peony) is a traditional ornamental flower. Because its short flowering period greatly limits the ornamental value of peony, the PoERF4 gene of ostii ‘Feng Dan’ was cloned to study its sequence and expression characteristics in different flowering periods, tissues, varieties and hormone treatments. This study aimed to provide a theoretical reference for further research on the regulation of PoERF4 during the flowering, growth and development of tree peony. 【Method】 Using ‘Feng Dan’ as the material, based on the results of the three-generation full-length transcriptome sequencing of ‘Feng Dan’, the sequences with high homology were screened, the PoERF4 gene was cloned by RT-PCR technology, and bioinformatics and expression pattern analysis were performed. 【Result】The open read frame (ORF) of the PoERF4 gene was 747 bp, which encoded 248 amino acids. The molecular formula of PoERF4 was C2 217H3 689N747O933S174, which is a hydrophilic protein containing a conserved AP2 superfamily domain with no transmembrane structure. The secondary structure contained 28 amino acids in the α-helix, 48 amino acids in the extended chain, and six amino acids in the β-turn. Fluorescence quantitative analysis found that the PoERF4 gene was mainly expressed in the petals of the half-opening period of ‘Feng Dan’ and it was expressed in different tissues of ‘Feng Dan’ peony, but its expression was highest in the leaves, followed by in the petals and roots. The expression level was the highest in the late-flower cultivar ‘Lianhe’. Under auxin treatment, the PoERF4 gene could respond. 【Conclusion】The PoERF4 gene was successfully isolated from ‘Feng Dan’ and it was speculated that it plays an important regulatory role in the development of flowers and leaves and is involved in the auxin signal transduction process of ‘Feng Dan’.
【Objective】This study aimed to investigate and analyze the volatile components of three wild tree peony species and identify the key volatile components and aroma-releasing sites. This was done to provide a reference for future research, such as on the breeding and genetic regulation of the floral fragrance of tree peony, and for the development of related products. 【Method】The volatile components in different parts of flower organs (whole flower, petals and stamens) of Paeonia ludlowii, P. lutea and P. ostii were analyzed using headspace-gas chromatography-mass spectrometry, and based on the identified volatile components, three tree peony species were analyzed by principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). 【Result】 A total of 147 volatile compounds were detected in the flowers of three species of tree peony. The main volatile components in P. ludlowii were ketones, alcohols, olefins and aldehydes. The main compounds in the whole flower of P. ludlowii were acetophenone, 6,6-dimethyl-bicyclo[3.1.1]heptane-2-carboxaldehyde and linalool, while β-copaene, acetophenone and linalool were the main compounds of petals, and acetophenone and linalool were the main compounds of stamens. The main components of P. lutea were olefins, alkanes and alcohols. α-pinene, β-copaene and linalool were the main compounds of the whole flower and petals in P. lutea, while 1-octane, β-copaene, and α-pinene were the main compounds of stamens. The main components of P. ostii were olefins and alkanes. The main compounds in the whole flower of P. ostii were α-pinene, ocimene and pentadecane; ocimene was the main compound of petals and its relative content was as high as 81.58%; and ocimene and pentadecane were the main compounds of stamens. These three tree peony species were effectively classified by the PCA and PLS-DA models based on their volatile components, and 15 differential components of the three peony species were identified using the PLS-DA model (VVIP > 1, P < 0.05). 【Conclusion】 There were significant differences among the types and relative contents of compounds among the three tree peony species and among different parts of the same tree peony species. The main aromatic components of P. ludlowii were acetophenone and linalool. The main aroma components of P. lutea were α-pinene, β-copaene and linalool. The main aroma components of P. ostii were ocimene, α-pinene and pentadecane. The relative alkane contents in the stamens of the three tree peony species were much higher than those in whole flowers and petals, suggesting that the stamen may be an important alkane synthesis site. Different volatile components formed the unique aroma characteristics of the three tree peony species, P. ludlowii and P. lutea showed intense floral attributes, whereas P. ostii had herbal and waxy attributes.
【Objective】 This research aims to evaluate the quality of persimmon fruits using three comprehensive methods in order to provide a theoretical basis for the precise selection and efficient utilization of high quality persimmon germplasm. 【Method】 We selected 85 persimmon germplasm resources in Zhejiang Province as the object of evaluation, and examined 13 quality indicators (weight per fruits, diameter of horizontal cross section, diameter of vertical cross section, content of the crude protein, vitamin C, starch, calcium and β-carotene, water content, content of the soluble solids, soluble sugar, tannin and crude fiber) of persimmon fruit. We employed the principal component analysis, the entropy evaluation method and the entropy-weighting TOPSIS method to evaluate fruit comprehensive quality. 【Result】 Fruit quality of different persimmon germplasm resources varied significantly with variation coefficients of 3.82%-87.89%. High variations were found in content of the β-carotene, tannin, starch, crude protein, vitamin C, calcium, fruit weight and crude fiber, and low variations were showed in horizontal and vertical cross section diameters, soluble sugar, soluble solids and water content. The principal component analysis revealed that top scoring persimmon germplasm fruits were Changxing 1, Fuyang 2, Fenghua 1 and Liandu 2. The entropy evaluation method ranked the top scoring persimmon fruits as Wuyi 3, Yongjia 10, Wuyi 4 and Huangyan 2. The entropy-weighting TOPSIS method gave top scoring persimmon fruits to Wuyi 3, Yongjia 10, Wuyi 4, and Chun'an 14. The entropy method and the entropy-weighting TOPSIS method showed relatively similar ranking, while the principal component analysis deviated from the other two methods in scoring. These three methods differ in their theoretical bases, in data standardization methods, and in an index weight assignment. The entropy-weighting TOPSIS based scoring overcame the complexity of the large amount of data on fruit trait indicators and the problem of small dispersion degree of key indicators, and matched best with the production performances and overall quality of different germplasm. 【Conclusion】 The entropy-weight based TOPSIS model simplifies and improves comprehensive evaluation of persimmon germplasm fruit quality compared with scoring by the principal component analysis and the entropy evaluation method.
【Objective】The fruit samples of 21 wild pomegranate plants collected in the dry-hot valley area of Tibet were comprehensively analyzed and evaluated to provide information for phenotypic database of wild pomegranate germplasms and provide scientific basis for breeding excellent pomegranate varieties.【Method】The fruit external and internal qualities of 21 pomegranate samples were determined by vernier caliper, electronic balance, texture analyzer and anthrone colorimetry, and the correlation analysis was carried out. Based on the comprehensive evaluation methods including ‘reasonable satisfaction’ and multidimensional value theory, 12 indexes, such as single fruit weight, fruit shape index, peel thickness, seed hardness, 100-aril weight, seed yield, soluble sugar content, soluble solids content, titratable acid content, vitamin C content, sugar-acid ratio and solid-acid ratio were selected to analyze and evaluate comprehensively.【Result】The fruit shape index of Gebu 5 was the largest. Junyong 1 had the smallest single fruit weight, the thinnest peel, the smallest 100-aril weight, and the lowest sugar-acid ratio. The peel thickness of Zela 1 was the largest; Changxi 1 had the largest 100-aril weight; the seed yield of Yeba 1 was the highest while Gula 3 the lowest. The content of soluble solids and soluble sugar in Gula 1 was the highest. Changxi 3 had the highest vitamin C content; sugar-acid ratio and solid-acid ratio of Zhula 1 were the largest. Correlations between some indexes were significant (P<0.05) or extremely significant (P < 0.01) positive or negative. The highest synthetic ‘reasonable satisfaction’ was Zhula 1. 【Conclusion】The fruit qualities of 21 wild pomegranate samples were significantly different. Most of wild pomegranates were characterized by small fruit, hard seed and high content of acids, indicating a rich genetic variability of wild pomegranate resources at the phenotypic level. According to the results of final synthetic ‘reasonable-satisfaction’, the overall fruit external and internal quality traits of Zhula 1 are optimal, which can be used as resources for introduction and selective breeding.
【Objective】 To better understand how 24-epibrassinolide (EBR) affects the development and physiological characteristics of ginkgo, different concentrations were sprayed onto ginkgo leaves, laying a theoretical basis upon which the oriented cultivation of ginkgo can be applied. 【Method】 Ginkgo leaves were placed in a randomized block design and treated with different concentrations of EBR (0-2.0 mg/L). The growth index, photosynthetic characteristics, and hormone content of EBR-treated annual seedlings were measured. 【Result】 The growth of ginkgo seedlings differed significantly following EBR treatment (P <0.05), with 1.0 mg/L EBR leading to increases of 23.6%, 52.6%, 140.2%, 87.7% and 69.1% in the maximum leaf length, leaf area, plant height, leaf weight and total weight, respectively, as compared to the control. Treatment with 1.5 mg/L (BR3) and 2.0 mg/L (BR4) led to increases of 40.2% and 41.5%, respectively, in the net photosynthetic rate as compared to the control. The maximum content of the endogenous hormones dihydrozein, indolepropionic acid, gibberellin, and abscisic acid and the minimum auxin content was observed under 1.5 mg/L EBR. The content of endogenous brassinolide was significantly positively correlated with the contents of methyl jasmonic and indolepropionic acid and negatively correlated with zeatin (R > 0.5, P < 0.05). 【Conclusion】 The results indicate that the exogenous spraying of ginkgo with EBR is an effective agronomic measure that could improve the net photosynthetic rate of gingko, while also regulating the content of endogenous hormones in the plant, thus promoting stem elongation, leaf area expansion, and leaf dry weight accumulation.
【Objective】The effects of different concentrations of abscisic acid (ABA) on the synthesis of flavonoids in Ginkgo biloba leaves were examined to provide a theoretical basis upon which the internal mechanisms of flavonoid accumulation in G. biloba leaves and leaf forest cultivation could be revealed.【Method】Annual ginkgo seedlings were placed in an artificial climate culture room and treated with exogenous ABA via foliar spraying at five concentration gradients; 0 μmol/L (CK), 50 μmol/L(A1), 100 μmol/L(A2), 150 μmol/L(A3) and 200 μmol/L(A4). The total flavonoid contents, components of G. biloba leaves, and the activities of key enzymes in the flavonoid synthesis pathway were measured, and the expression changes of key enzyme genes involved in G. biloba flavonoid biosynthesis were analyzed using real-time fluorescence quantitative PCR. 【Result】 ABA treatment had a significant effect on both total flavonoid content and components such as quercetin, kaempferol and isorhamnetin. Increasing the ABA concentration led to an initial increase in the total flavonoid and component content, which was followed by a decrease. The highest total flavonoids, quercetin and isorhamnetin were observed under treatment A3, while the highest kaempferol was associated with A2. ABA treatment had a significant effect on the activities of key enzymes that are involved in flavonoid synthesis in G. biloba leaves (PAL, C4H and 4CL); however, differences were observed in the change trends of the different enzymes. PAL enzyme activity increased gradually as ABA concentrations increased; C4H activity increased and decreased alongside the total flavonoid content; 4CL activity was significantly higher under treatments A2 and A3 than the control; however, 4CL activity was lower under A1 and A4 than the control. The results of real-time fluorescence quantitative PCR showed that ABA treatment significantly improves the expression levels of GbPAL,GbC4H,Gb4CL,GbCHS and GbCHI. In general, exogenous ABA improves the flavonoid synthesis in G. biloba leaves, with the best effects observed under treatment A3.【Conclusion】The use of appropriate ABA concentrations can positively regulate the expression of multiple key enzyme genes that code for flavonoid synthesis, improve the activity of key enzymes involved in flavonoid synthesis, and thus promoting the synthesis and accumulation of flavonoids in G. biloba leaves.
【Objective】A common garden experiment was used to explore the adaptation mechanisms of leaf structure to geographical environment changes. 【Method】In this study, the anatomical structure and stomatal characteristics of the leaves of 46 Vernicia fordii provenances were observed and measured by the paraffin wax slices method and nail oil seal method. Redundancy analysis, traditional correlation analysis and systematic clustering were used to analyze the differences in leaf structural characteristics, as well as the relationship between leaf traits and environmental factors.【Result】The results showed that the leaf structure characteristics of V. fordii had significant variation (P<0.01), the coefficients of variation of P/S, stomatal area, stomatal density and spongy tissue thickness were more than 20%. There were significant correlations between the leaf anatomical structure and leaf stomatal structure. Latitude, longitude, mean annual temperature and mean annual precipitation contributed largely to the variations of leaf structure characteristics of V. fordii. Principal component analysis revealed that the first five principal components represented 91.02%. Ten indexes, including stomatal density, stomatal perimeter and stomatal area, were selected for hierarchical cluster analysis. Overall, 46 V. fordii germplasms were clustered into three groups with a Euclidean distance of 5.0. The clustering results reflected the characteristics of the leaf tissue structure of various groups, and the difference was mainly reflected in the stomatal characteristics. 【Conclusion】 The difference in the geographical environment was one of the major factors that affected the variations of the leaf structure of V. fordii.
The application of nitrogen fertilizer is the main driving force for biomass production in artificial systems of agriculture and forestry. However, problems such as the increased cost and substantial pollution of soil, water and atmosphere are resulted from nitrogen leaching. Improving plant nitrogen use efficiency (NUE) is the crucial way to resolve these problems. NUE is a complex trait associated with an interplay between the genetic background and environmental factors, and is the comprehensive reflection of respective efficiencies with uptake of soil nitrogen by plant roots, assimilation and utilization of absorbed nitrogen inside plants, and resorption of nitrogen from senescent tissues or organs. The physiological steps of nitrogen resorption include a protein degradation in senescing organs,amino acid interconversion, and phloem loading of amino acids for remobilization. Phloem loading is thought to be the rate-limiting step of nitrogen resorption from senescing leaves. Nitrogen resorption is always accompanied with either natural senescence of the whole plant or certain tissues/organs determined by a developmental age or precocious senescence induced by environmental stresses. Nitrogen resorption in senescing leaves is an important strategy for perennial woody plants to conserve intrinsic nitrogen and increase stress tolerance through the winter season. The efficiency of nitrogen resorption is not only associated with species, age and functional types (i.e. deciduous or evergreen, broad- or needle-leaved) of woody plants, but also influenced by environmental factors such as geographic habitat, status of soil nitrogen and water supply. Improving efficiency of nitrogen resorption from senescing leaves may alleviate the requirement of trees for nitrogen fertilizer in the next growth season. As studies about mechanisms of leaf senescence and nitrogen resorption in trees are rare at present, characterization of key factors (such as NAC and WRKY family members) regulating leaf senescence, certain transporters responsible for phloem loading of amino acids in senescing leaves and signaling components mediating functions of phytohormones (such as abscisic acid and ethylene) which may promote leaf senescence is desired in woody plants in coming years, thus providing putative technological supports for breeding tree cultivars with the improved NUE through the genetic modification.
【Objective】 Circular RNAs (circRNAs) are a class of endogenous non-coding RNA produced by reverse alternative splicing of transcripts, which play crucial roles in plant growth and development. This study aimed to identify circRNAs in germinated seeds of moso bamboo (Phyllostachys edulis), and investigate their expression under drought and salt stress conditions, providing a foundation for exploring the molecular regulation mechanism of bamboo seed germination under abiotic stress resistance. 【Method】 polyethylene glycol (PEG) 6000 and NaCl were used to simulate drought and salt stress, respectively. The strand specific libraries were constructed for moso bamboo seeds samples at the seed coat rupture stage under treatments of H2O, 10% (mass fraction) PEG, 15% PEG, 50 and 100 mol/L NaCl. High throughout sequencing and biological information analysis were used to identify and analysis the expressional pattern of circRNAs. 【Result】 A total of 1 446 circRNAs were identified in all samples, with 76.34% of circRNAs originating from exon region; The circRNAs with the highest expression levels in bamboo germinating seeds under different treatments were identified as plant_ circ_ 0001703, plant_ circ_ 0001728, plant_ circ_ 0000358, plant_ circ_ 0001236 and plant_ circ_ 0001728;Compared with control, 524, 505, 467 and 474 circRNAs were significantly differentially expressed in germinating seeds under the four stress treatments. The original genes of differentially expressed circRNAs were significantly enriched in various GO and KEGG pathways. 【Conclusion】 A total of 1 446 circRNAs were found to be expressed in moso bamboo germinating seeds, with 1 056 circRNAs responding to drought or salinity stresses during seed germination. Genes involved in acylhydrolase enzyme activity and sphingolipid metabolism pathways may play a crucial role in regulating bamboo seed germination under PEG or NaCl stress conditions.
【Objective】The study explored the changes of water content, storage substance content, and enzyme activity during the germination process of Pinus bungeana seeds, in order to reveal the physiological mechanism of temperature that affects the seed germination. 【Method】Seed germination was performed at various temperatures to study the effects of temperature on the extent of germination. Physiological indicators, such as the content of water, soluble sugar, starch, soluble protein, crude fat and the activities of amylase, protease and acid phosphatase were measured during the germination process. 【Result】A high germination percentage (approximately 90%) was obtained when the seeds were cultured at 15 and 20 ℃. As the culture temperature continued to rise to 25 and 30 ℃, the radicle protrusion and seed germination were seriously hindered, resulting in a sharp drop in germination percentage to <10%. At 20 ℃, the change of water content during germination could be characterized into three stages: rapid increase, period of retardation, and another rapid increase. During germination, the catabolism and anabolism of substances occurred vigorously in the seeds. The soluble sugar content initially decreased and then gradually increased. As starch began to hydrolyze with a decreased content after six days of cultivation, the crude fat and soluble protein were degraded into small molecules as catalyzed by the corresponding enzymes for embryo utilization after 10 days of cultivation. At 25 ℃, the water absorption process of seeds stayed in the retardation period throughout. At this incubation temperature, the activities of acid phosphatase, amylase, and protease in seeds was inhibited due to the excessive temperature, thus affecting the degradation of crude fat, soluble protein and soluble starch. In addition, the soluble sugar content was slightly decreased to keep the ‘still’ state of the seeds with low consumption. 【Conclusion】The suitable temperature range for seed germination of P. bungeana was 15-20 ℃. However, if the temperature continued to rise, seed germination was hindered and thermal inhibition occurred. At the favorable temperature of 20 ℃, seeds would preferentially use the nutrients stored in the embryo when germination occurred. Carbohydrates are first decomposed and utilized, followed by the mobilization of proteins and lipids. Degradation of a large amount of fat began after the radicle broke through the seed coat. At a high temperature of 25 ℃, the activity of enzymes in the seeds was inhibited, resulting in the catabolism of macromolecular substances was hindered. Ultimately, the embryo could not absorb and utilize enough nutrients to complete the germination process.
【Objective】The study explored the effects of brassinolide (BR) on enzyme activities related to fatty acid synthesis and oil accumulation in seeds of Styrax tonkinensis. The aim was to provide theoretical and practical data for studies of the mechanism by which exogenous BR promotes fatty acid synthesis and oil accumulation in seeds of S. tonkinensis. 【Method】Ten-year-old seed trees of S. tonkinensis were sprayed with four different concentrations of brassinolide solution: 1(BR 1), 5(BR 5), 10(BR 10) and 20(BR 20) μmol/L, with distilled water sprayed as the control. The different BR concentrations were sprayed 45, 65, 95 and 125 d after flowering. Fruit samples were collected 50, 70, 100 and 130 d after flowering. The activities of fatty acid synthase (FAS), 1-aminocyclopropane-1-carboxylate (ACC) and diacylglycerol acyltransferase (DGAT) were measured during seed development. Fruit fresh weight and seed crude fat mass fraction were also determined. The effects of different concentrations of BR on enzyme activities related to fatty acid synthesis in S. tonkinensis seeds were analyzed. 【Result】BR treatment had significant effects on the activities of enzymes related to fatty acid synthesis during the seed development of S. tonkinensis. FAS activity was low at 50 d after flowering, increased, significantly and peaked at 100 d after flowering, and then decreased slowly. At 100 d after flowering, the activity of FAS in the BR5 and BR10 treatments reached the maximum value at the same time. The respective values of 329.104 and 326.744 nmol/(min·mg) exceeded the control value by 1.8 times. The ACC activity of S. tonkinensis seeds increased, then decreased, then increased again. At 70 d after flowering, the ACC activity in the BR5 treatment peaked 20.50 nmol/mg, which was 5.9 times that of the control group. The activity of DGAT in the different treatments first increased and then decreased, reaching a peak at 100 d after flowering. The activity of DGAT in each BR treatment group was significantly higher than that in the control group. DGAT activity in the BR5 treatment was highest at 6.03 nmol/mg, which was 1.2 times of that the control group. BR promoted the activities of FAS, ACC and DGAT in S. tonkinensis seeds, with the most significant effect with the BR5 treatment. During the four periods of time, the medium concentration of BR treatment improved the crude fat fraction of S. tonkinensis seeds. Seventy days after flowering, there were significant differences in the seed crude fat mass fraction under different treatments, and that of the BR5 treatment was significantly higher than that of the other treatments. The fresh weight of S. tonkinensis fruits increased after treatment with different concentrations of BR. The BR5 treatment had the greatest effect on fruit fresh weight, except at 100 d after flowering. There was a significant positive correlation between enzyme activities related to fatty acid synthesis and both seed crude fat mass fraction and fruit fresh weight. 【Conclusion】 The dynamic changes in FAS, ACC and DGAT activities showed that BR treatment increased the activities of enzymes related to fatty acid synthesis and promoted fatty acid synthesis during seed development. The BR5 treatment had the best effect. BR treatment also increased fruit fresh weight and seed crude fat fraction. Correlation analysis showed that the activities of enzymes related to fatty acid synthesis in the seeds of S. tonkinensis were positively correlated with fruit fresh weight and seed crude fat mass fraction.
【Objective】Using low-field nuclear magnetic resonance (NMR) technology, changes in the water phase during the imbibition and stratification of Cercis chinensis seeds were detected nondestructively. Combined with the nutrient content changes during stratification, the role of each water phase was analyzed to reveal the material base and physiological conditions during the germination of C. chinensis seeds. 【Method】After being treated with hot water at 80 ℃, the hardness of C. chinensis seeds was removed and its water absorption curve was calculated by the gravimetric method. Cold stratification was applied to break the physiological dormancy of C. chinensis seeds by random selection. The germination percentage and nutrient content of seeds were determined during different stratification periods. Low-field NMR was employed to investigate the dynamic transitions of the water phase and water content during imbibition and stratification. 【Result】(1)Hot water immersion at 80 ℃ for 5 min followed by 60 days of cold stratification effectively improved the germination rate of C. chinensis seeds. (2)The water absorption curve of C. chinensis seeds exhibited an “S” type variation and from 0 h to 9 h was the rapid water absorption stage. At from 9 h to 24 h, seed water absorption gradually slowed. Ultimately, the seeds entered a balanced water absorption stage after 24 h. (3)NMR spectra revealed that the water mass (x) of C. chinensis seeds and the peak areas of the NMR relaxation spectra (y) exhibited a significant linear relationship, according to the linear regression equation y = 164 604.7 x + 4 962.3, with a correlation coefficient R2 = 0.999 6. (4)NMR T2 relaxation spectra enabled division of the water phases during the imbibition process of C. chinensis seeds into three types: bound water T2a, free water T2b, and newly absorbed water T2c. (5)During the water absorption process from 0 to 3 h, the content of T2a decreased continuously, whereas T2b content increased dramatically. After 3 h, T2c appeared and T2a disappeared. Only T2b and T2c existed in the seeds; both showed an increasing trend, with the peak maximum moving to the right and water mobility being enhanced. Peaks T2b and T2c shifted to the right during stratification, with fluctuating changes in peak area and peak ratio, and in general showed a trend towards increased water mobility. (6)During the stratification process of C. chinensis seeds, the starch content continued to decrease, soluble sugar content increased, and soluble protein content showed an increasing trend, followed by a decreasing trend. 【Conclusion】Water mobility is enhanced during the absorption and the stratification of C. chinensis seeds. There are three types of water phases in the imbibition process of C. chinensis seeds: T2a, T2b and T2c. However, only T2b and T2c appear during stratification. The changes in the nutrient contents of starch, soluble sugars, and soluble proteins roughly follow the same trend as those in T2b content. The fluctuations in water in each phase provides a suitable water environment for C. chinensis seed germination, and the changes in T2b during the stratification process might be closely related to germination.
【Objective】This manuscript described the realized genetic gain and construction techniques of an open-pollinated seedling and seed orchard of Masson pine (Pinus massoniana). 【Method】The orchard was established in the 1990 to 1992 period and covers an area of 33.33 hm2 in Baisha State-Owned Forest Farm, Shanghang County, Fujian Province, China. The orchard comprises more than 198 families of trees that were intensively selected from the excellent provenance area of Fujian Province. The orchard design was classified into two types: (1) Combined design of seed production area with progeny test area. (2) Separated design of seed production area and progeny test area. Based on the results of open-pollinated forests progeny test, trees with the lower breeding values were removed from the seed orchard (genetic thinning) on three occasions in 2000, 2004 and 2008, respectively. In 2003, a progeny test forest with seedlings from 68 half-sib families of the seedling seed orchard including a commercial check was established.【Result】A realistic genetic gain of 8.5% was obtained based on a test of 6-year offspring of Masson pine open-pollinated seedling seed orchard, and the volume growth of improved seed plantation was increased by 30% more than that of the unimproved stand. The results of simple sequence repeat (SSR) molecular analysis showed that the seedling seed orchards had high genetic diversity and random mating degree. The establishment of the first generation free-pollinated seed garden of Masson pine was successful. The following are the two key findings: (1) Quality and quantity of superior tree selection is the basis for achieving high genetic gain and continuing genetic improvement. (2) Scientific genetic evaluation of the progeny population and genetic thinning in the production population are the key techniques. (3) The detection, regulation and daily management of the mating system in a seed orchard are important conditions to ensure the normal operation of the orchand. 【Conclusion】 (1) For some fast-growing tree species such as eucalyptus and Masson pine, the seed orchard crops are not appropriate for pruning and dwarfing culture. It is more advantageous to adopt the technique of “Integrating the measured population and the producing population” to build the orchard. (2) Information regarding juvenile-adult correlation of the main traits of the established tree species is not yet available. It is necessary to carry out pruning and dwarfing culture. It is valuable to use the separated design of seed production area and progeny test area and to use the genetic evaluation data obtained from the separated progeny test to guide the genetic thinning of production population in the seed orchard production. In a word, the multi-generation seed orchard should be established in a location with good isolation conditions and relatively gentle terrain, and the orchard crops should be maintained without pruning and dwarfing to retain the natural tree shape. After completion of the production task in the seed orchards, the seed orchard trees could be transformed into forest tourism forest, forest health forest or timber reserve forest, to give full play to the multiple functions of the forest and reduce the operating cost of the forest improved seed base. This is a new model of multi-generation low-cost construction of seed orchards worth exploring.
【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’.
【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.
【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.
【Objective】This study aimed to provide a theoretical basis for the strategic cultivation of plantations, and to increase the content of bioactive substances in leaves by investigating the effects of various nitrogen and phosphorus levels on the growth and bioactive substance content in Cyclocarya paliurus leaves.【Method】The research is conducted in the field and utilized a two-factor complete block design, incorporating three levels of nitrogen application (N0, N1, N2) and three levels of phosphorus application (P0, P1, P2), creating nine treatments with three replicates each. The growth indexes of seedlings and the contents of total flavonoids, total triterpenoids, total polyphenols and total polysaccharides in leaves were determined. A two-way ANOVA was used to compare the effects of nitrogen and phosphorus and their interaction on related indexes.【Result】The study found that different ratios of nitrogen and phosphorus significantly influenced both the growth and the bioactive substance content in C. paliurus leaves (P<0.05). The contents of total flavonoids, triterpenoids, and polyphenols in the leaves exhibited a parabolic seasonal variation, peaking in July, while the highest polysaccharides content was observed in September. Compared to the control treatment (N0P0), all nitrogen and phosphorus fertilizations enhanced tree growth, with the most substantial growth in tree height and ground diameter occurring in the N2P2 treatment. The effects of nitrogen and phosphorus ratios on the bioactive substances varied, displaying differences among the substances and the sampling months sampled. The variation in the contents of total flavonoid, total triterpenoids, total polyphenols and total polysaccharides in June ranged from 17.01 to 34.25 mg/g, from 39.11 to 55.77 mg/g, from 22.74 to 53.98 mg/g, and from 22.36 to 33.24 mg/g, respectively, while in October, the ranges were 16.95-35.26, 38.03-54.17, 19.78-33.98 and 23.33-32.46 mg/g, respectively. Correlation analysis revealed no significant relationship between the monthly growth in tree height and the content of bioactive substances (total flavonoid, total triterpenoids, total polyphenols and total polysaccharides) in the leaves (P>0.05). However, weakly negative correlations were observed between the ground diameter growth and the contents of total triterpenoids and total polyphenols in the leaves (P<0.05). Notably, there were significant positive correlations between the growth of tree height and ground diameter, as well as among the different bioactive substances (P<0.01).【 Conclusion】A high ratio of nitrogen and phosphorus addition benefit the growth of C. paliurus and enhances the content of total triterpenoids in the leaves. Sole nitrogen or phosphorus supplements boost the content of secondary metabolites, whereas a combined application tends to decrease the content of total polysaccharides. There is a noticeable trade-off between the growth of C. paliurus and the content of secondary metabolites in its leaves.
【Objective】Genomic simple repeat sequence (SSR) loci were analyzed by screening the whole genome of Cyclocarya paliurus. DNA molecular ID cards of 19 excellent medicinal clones of C. paliurus were constructed based on the newly-developed SSR primers. These genomic SSR markers could support further research, such as the evaluation of the germplasm resource, analysis of genetic diversity, and identification of cultivars/clones.【Method】The SSR loci were screened along with the whole genome of C. paliurus and were enriched and analyzed using MISA software. Subsequently, SSR primers were designed using Primer 3.0. Furthermore, a system for identifying clones of C. paliurus was constructed based on selected SSR markers with high reproducibility and stability.【Result】(1) We detected 89 741 SSR loci from the whole genome, with an occurrence frequency of 62.07%. (2) Among all SSR loci, the proportion of SSRs with a mononucleotide motif was the highest (62.67%) and a hexa-nucleotide repeat was the lowest (0.15%). Most of the repeated motifs in the SSR loci were dominated by (A/T)n. (3) The repeat number of mono-nucleotide and di-nucleotide motifs ranged from 6 to 16. With the increase in the repeat number, the frequencies of various SSR repetition types displayed a downward trend. (4) The length of the SSR sequences varied from 10 to 476 bp, and this length variation existed in different repetitive motifs. Additionally, the frequency of SSR occurrence tended to decrease as the repeat number increased. (5) We successfully designed 78 285 pairs of SSR primers using Primer 3.0. A total of 377 primer pairs were randomly synthesized for amplifying polymorphic SSR fragments, among which 75 pairs primers were successful. Moreover, quick response code DNA molecular ID cards for 19 medical-use clones of C. paliurus were constructed by five pairs of polymorphic SSR primers with a mono-nucleotide motif.【Conclusion】The frequency of genomic SSR loci was high, and there was variability in the type of SSR loci. Simple repeat sequences developed from the whole genome of C. paliurus could be effective candidate molecular markers with further applications in germplasm resource evaluation and fingerprint construction for multi-use clones of C. paliurus.
【Objective】To compare the differences in leaf phenotypes characters, anatomical structures and stomatal characteristics between diploid and tetraploid Cyclocarya paliurus, we obtained data on the leaf characteristics of C. paliurus with different ploidy.【Method】Diploid and tetraploid seedlings of C. paliurus were used as study materials, and 32 leaf traits were measured. Independent samples t-tests, a correlation analysis, and principal component analysis (PCA) were conducted.【Result】There were no significant differences between diploid and tetraploid seedlings for sawtooth width and the position of the maximum leaf width of the middle leaflet. For the other 30 leaf traits, there were significant or extremely significant differences between diploid and tetraploid seedlings. Among them, the number of leaflets of tetraploids was significantly less than that of diploids, while the area and specific leaf weight of compound leaves of tetraploids were significantly greater than those of diploids. The length, width and area of the terminal and middle leaflets of tetraploids were significantly greater than those of diploids, while the leaf shape index was significantly smaller than that of diploids. The sawtooth density of tetraploids was significantly smaller than that of diploids. The leaflet thickness, the upper epidermis thickness, lower epidermis thickness, palisade tissue thickness, and sponge tissue thickness of tetraploids were all significantly higher than those of diploids, while the ratio of palisade tissue to sponge tissue and cell tense ratio were significantly smaller than those of diploids. The stomatal length and width of tetraploids were significantly greater than those of diploids, while the stomatal density was significantly smaller than that of diploids. The correlation analysis results indicated that there were broad and significant correlations between the phenotypic characteristics, anatomical structure, and stomatal characteristics of C. paliurus. The indicators reflecting the differences of leaf characteristics between diploid and tetraploid C. paliurus were extracted by a PCA, including leaflet width, leaflet area, leaf shape index, sponge tissue thickness, stomatal length, palisade tissue thickness and cell tense ratio.【Conclusion】There were significant differences in leaf traits between diploid and tetraploid C. paliurus, and leaf phenotypic characteristics, such as leaflet width, leaflet area, and leaf shape index, can be used for the preliminary screening of diploid and tetraploid C. paliurus.
【Objective】To provide a theoretical basis for the introduction, selective breeding, and cultivation of Cyclocarya paliurus, the cold resistance of different families of C. paliurus under natural low temperature stress was evaluated.【Method】Using the current branches of C. paliurus from 23 families as materials, the relative electric conductivity (REC), malondialdehyde (MDA) content, peroxidase (POD) activity, superoxide dismutase (SOD) activity, soluble sugar (SS), soluble protein (SP), starch (ST) and free proline (Pro) content were determined after natural low temperature stress. A preliminary evaluation of the cold resistance of C. paliurus families was conducted through a principal component analysis (PCA) and cluster analysis.【Result】After natural low temperature stress, there were significant differences in the REC, MDA, POD and SOD activity, SS, SP, ST and Pro content among the current branches of the 23 families. The PCA found that the four principal components represented 72.4% of the information regarding the various physiological indicators. A cluster analysis showed that the cold resistance of 23 families could be divided into three categories based on the comprehensive score of the PCA for each family. The first category included only two families (SCMC31 and ZJTTS2) with the good cold resistance, and the compositive score ranging from 1.208 to 1.284. The second category indude 17 families (including GZSQ12, GXBS12, ZJFYS6, AHQLF8 and HBWF10) that exhibited moderate cold resistance, with composite scores ranging from -0.343 to 0.631. The third category included four families (GZSQ9, ZJTTS3, SCMC22, and SCMC30) with poor cold tolerance, with composite scores ranging from -1.259 to -0.745.【Conclusion】After natural low temperature stress, significant differences in the measured physiological indices were observed between the current branches of C. paliurus from different families (P < 0.05). Based on the PCA and cluster analysis results, there were different cold resistances among the 23 Cyclocarya paliurus families, which could be divided into three categories. The results not only provide a basis for an in-depth study of the cold tolerate mechanism of C. paliurus, but also for future screening of the cold tolerate genotypes of C. paliurus.
【Objective】The present study aimed to investigate the characteristics of sap flow velocity of Sapindus saponaria and its response pattern to pruning and meteorological factors during the key phenological periods, and to provide a theoretical reference for scientific water management during key reproductive phenological periods of Sapindus.【Method】The present study was conducted in the experimental area of the Sapindus National Forest Germplasm Repository in Jianning County, Sanming City, Fujian Province. Using five-year-old S. saponaria ‘Yuanhua’. Thermal dissipation probes (TDPs) and automatic weather stations were utilized to monitor sap flow and meteorological data from April 20, 2021 to November 9, 2021. The probes were installed approximately 30 cm above the ground to ensure that all probes were installed under the first branch. Sample trees in the pruning group were pruned once after inflorescence growth at the inflorescence growth period to remove branches and leaves that shaded the inflorescence from sunlight. Trees in the control group were left unpruned for comparison.【Result】The average daily sap flow velocity of S. saponaria showed a decreasing-increasing-decreasing trend over time during the seven key reproductive phenological periods. The strongest transpiration activities were (1.13±0.05)×10-3 cm/s (pruning) and (1.48±0.05)×10-3 cm/s (CK) in the early ovary growing period, while the weakest transpiration activities were (0.15±0.02)×10-3 cm/s (pruning) and (0.26±0.03)×10-3 cm/s (CK) in the fruit maturity period. Pruning significantly reduced the sap flow velocity of S. saponaria in all phenological periods, except for the bud swelling period. This reduction effect was more pronounced on sunny days when the tree was actively growing and was strongest at the end of the fruit development period. In addition, solar radiation, air temperature, wind speed and vapor pressure deficit (VPD) were the main drivers of sap flow velocity, while precipitation and air humidity were the main limiting factors. Meteorological factors, such as persistent rainfall, were the main limitations of the transpiration activity of S. saponaria from the bud swelling period to the early flowering period and middle fruit development period. Leaf aging and gradual dormancy of the tree were the main reasons for low sap flow velocity during the fruit maturity period.【Conclusion】Pruning significantly reduced the transpiration, with the reduction effect becoming more pronounced as the phenological periods progressed. There were large fluctuations in sap flow velocity throughout the reproductive growth of S. saponaria. Thus, these findings suggested that the water demand for tree and fruit growth is closely related to the water consumption behavior of trees. Meteorological factors, such as persistent excessive rainfall, during inflorescence growth and development are not conducive to transpiration.
【Objective】The study aimed to explore the effects of the combined application of nitrogen (N), phosphorus (P), and potassium (K) fertilizers on the growth and photosynthetic characteristics of the ‘Yuanhua’ and ‘Yueshuo Bodhi’ of Sapindus saponaria, and to provide a theoretical basis for the scientific fertilization of disease-free clones.【Method】Using the S. saponaria ‘Yuanhua’ and ‘Yueshuo Bodhi’ as the experimental materials, the “3414” field experimental method was used to study the effects of different N, P, and K fertilization regimes on the growth and photosynthetic characteristics of the S. saponaria.【Result】The tree heights of the offspring of S. saponaria were greatest following treatment with N2P1K2 and N2P2K3, being 28.42% and 39.14% higher, respectively, than that of the control, and the differences were found to be significant (P < 0.05). The ground diameter was largest following treatment with N1P2K1 and N2P3K2, and increased by 16.11% and 32.93%, respectively, compared to that of the control (N0P0K0). The tree heights and ground diameters of the ‘Yuanhua’ were in the following order: P > N > K, under different fertilization treatments, while those of the ‘Yueshuo Bodhi’ were in the order: N > K > P. The net photosynthetic rate of the ‘Yuanhua’ and ‘Yueshuo Bodhi’ was highest following treatment with N2P2K2 under different fertilization regimes, and increased significantly by 42.19% and 53.01%, respectively, compared to that of the control. The net photosynthetic rate, intercellular CO2 concentration, rate of transpiration, and foliar water use efficiency of the treatment groups improved significantly; however, the stomatal conductance of the ‘Yuanhua’ did not alter significantly, and the stomatal conductance of the ‘Yueshuo Bodhi’ differed significantly, The quantity of N fertilizer applied exhibited a significant positive correlation with the tree heights and ground diameters of ‘Yuanhua’ and ‘Yueshuo Bodhi’ trees. The growth and photosynthetic indicators of the ‘Yuanhua’ and ‘Yueshuo Bodhi’ under different fertilization regimes were comprehensively evaluated using the entropy weighted TOPSIS method. The findings revealed that N2P1K2 and N1P2K2 were superior for the fertilization of ‘Yuanhua’ trees, while N1P1K2 and N2P2K2 were superior for the fertilization of the ‘Yueshuo Bodhi’.【Conclusion】The application of N, P and K at an appropriate ratio can effectively promote the growth and photosynthetic characteristics of ‘Yuanhua’ and ‘Yueshuo Bodhi’ trees. The optimal strategy for the application of N, P, and K fertilizers is that the quantities of N, P and K should be 115.26, 64.14 and 44.37 kg/hm2, respectively, for the ‘Yuanhua’, and 117.90, 87.65 and 36.11 kg/hm2, respectively, for ‘Yueshuo Bodhi’ trees.
【Objective】This study aimed to systematically characterize the BZR1 transcription factor family in yellowhorn (Xanthoceras sorbifolium) and elucidate its functional roles in abiotic stress response, thereby providing insights for breeding stress-resistant cultivars.【Method】Genome-wide identification of XsBZR1 genes was performed using bioinformatics tools. Subcellular localization of XsBZR1 proteins was validated via 35S::XsBZR1-eYFP fusion constructs. Expression profiles under abiotic stresses (low temperature, salt, drought) and abscisic acid (ABA) treatment were analyzed by qRT-PCR. Functional validation was conducted by overexpressing XsBZR1- 9 in Arabidopsis thaliana and assessing salt tolerance phenotypes.【Result】Nine XsBZR1 genes (XsBZR1-1 to XsBZR1-9) were identified and distributed unevenly across six chromosomes. Phylogenetic and synteny analyses revealed close evolutionary relationships with dicotyledonous BZR1 orthologs. Promoter regions harbored abundant cis-regulatory elements associated with light responsiveness (48.9%), hormone signaling (35.0%) and stress adaptation (24.6%). The nuclear localization of all XsBZR1 proteins was experimentally confirmed. Differential expression patterns were observed under stress conditions: low temperature (4 ℃) rapidly induced eight XsBZR1 genes (1.3- to 6.0-fold upregulation at 3 h; P<0.05), except XsBZR1-7. Salt stress (150 mmol/L NaCl) suppressed XsBZR1-3/4/5/7 but strongly upregulated XsBZR1-1 (26.1-fold) and XsBZR1-9 (19.6-fold) at 9 h (P<0.001). Drought stress (mass fraction 25% PEG6000) elevated XsBZR1- 3/7/8/9 expression (>1.9-fold at 9 h), while others remained stable. ABA treatment (100 μmol/L) universally induced XsBZR1 genes, with XsBZR1-8 showing a 35.4-fold increase (P<0.001).Transgenic Arabidopsis overexpressing XsBZR1-9 exhibited enhanced salt tolerance, with taproot lengths twice that of the wild-type under 100 mmol/L NaCl (P<0.01).【Conclusion】The XsBZR1 gene family plays pivotal roles in yellowhorn’s abiotic stress response, with XsBZR1-9 demonstrating significant potential for improving salt tolerance. These findings advance the molecular understanding of stress adaptation mechanisms in woody plants and provide targets for precision breeding.
【Objective】This study aimed to characterize the sequence identity, transcriptional activation potential, and functional domains of the WRINKLED1 (WRI1) transcription factor in Xanthoceras sorbifolium (yellowhorn), providing insights into its regulatory role in seed oil biosynthesis. 【Method】The full-length cDNA of XsWRI1 was cloned from endosperm tissues of mature yellowhorn using rapid amplification of cDNA ends (RACE). Bioinformatics tools were employed to analyze protein sequence properties. A recombinant pGBKT7-XsWRI1 vector was constructed and transformed into Y2HGold yeast cells to assess transcriptional activation activity. Tissue-specific expression patterns were quantified via quantitative real-time PCR (qRT-PCR) across the root, stem, leaf, petal, stamen and developing embryo tissues. 【Result】The XsWRI1 gene (GenBank accession: OR500287) spans 1 688 bp, encoding a hydrophilic and unstable protein of 414 amino acids. Yeast activity testing confirmed strong transcriptional activation activity of XsWRI1. Tissue-specific expression analysis revealed predominant XsWRI1 expression in developing embryos, with negligible levels in vegetative organs (root, stem, leaf) and reproductive structures (petal, stamen). Structural prediction identified two conserved AP2/EREBP DNA-binding domains (residues 76-148 and 177-238) and a nuclear localization signal. 【Conclusion】This study elucidates the molecular characteristics and tissue-specific regulatory role of XsWRI1 in yellowhorn, highlighting its potential function in lipid biosynthesis pathways. These findings establish a foundation for targeted genetic manipulation to enhance seed oil accumulation in woody oil crops.
【Objective】 Xanthoceras sorbifolium is a unique woody oil-bearing tree species native to China. In addition to the value of its seed oil, the saponins in the fruit husk also have significant utilization values in production. This study aims to analyze the dynamic changes in fruit morphological traits, kernel oil content, saponin, soluble sugar, and starch content during the growth and development of fruits from superior clonal lines of X. sorbifolium, intending to provide a scientific basis for the efficient cultivation and fruit harvesting strategies. 【Method】 The study observed the dynamic changes in the growth and development of the fruits and their internal content and constructed a growth model accordingly. 【Result】 (1) The development processes of fruit transverse and longitudinal diameters followed sigmoid growth curves. Fruit development can be divided into four stages: the initial growth stage (1-16 days after flowering), the rapid growth stage (17-38 days after flowering), the late growth stage (39-45 days after flowering), and the fruit maturity stage (46-80 days after flowering). (2) The key periods for accumulating seed oil and fruit peel saponins were 45-80 days and 55-65 days after flowering, respectively. The peak values appeared at 80 days (62.75%) and 65 days (1.599%). Peak values for soluble sugars and starch occurred at 75 and 65 days after flowering. (3) The contents of saponin, soluble sugar, and starch in the fruit showed a highly significant positive correlation with the transverse and longitudinal diameters and the fruit’s fresh weight. 【Conclusion】 The optimal harvesting period for X. sorbifolium fruits for oil usage is 75-80 days after flowering, during which the transverse diameter of the fruit ranges from 64.82 to 66.47 mm, and the longitudinal diameter from 67.26 to 69.97 mm. For saponin usage, 60-65 days after flowering is suitable for fruit harvest, at which time the transverse diameter of fruits is 62.64 to 63.63 mm, and the longitudinal diameter is 65.57 to 65.94 mm.
【Objective】 This study aimed to evaluate the variation in phenotypic traits, leaf nutrient content, and enzyme activities among 23 clonal lines of Xanthoceras sorbifolium, and to examine their interrelations. The findings aim to provide a scientific foundation for the targeted cultivation, introduction and promotion of superior clonal lines of leaf-use X. sorbifolium. 【Method】 Twenty-three clonal lines of X. sorbifolia, introduced to Yancheng Forest Farm in Jiangsu Province, were used as research subjects. Variation was assessed by analyzing the coefficient of variation across 15 key indicators. Pearson correlation coefficients were calculated to determine the relationships between phenotypic traits, leaf nutrients and enzyme activities. Principal component analysis and hierarchical clustering were applied to comprehensively evaluate and classify the clonal lines. 【Result】 The 15 indicators exhibited varying degrees of variation, with coefficients ranging from 6.17% to 43.00%. Significant correlations were identified: nine pairs of indicators showed extremely significant correlations (P<0.01), while five pairs demonstrated significant correlations (P<0.05).【 Conclusion】 Leaf traits among the clonal lines of X. sorbifolium display substantial variation, indicating strong potential for selective improvement. The superior clonal lines identified were 50, Y8 and Y11, which are recommended for further cultivation and introduction in the Yancheng region.
【Objective】In this study, 24 hybrids were made using blueberries of three distinct cultivation cultivar including Vaccinium corymbosum ‘O’Neal’, V. ashei ‘Pink Lemonade’ and V. ashei ‘Bonita’ as the male parent and three ploidy types of blueberries as the female parent. We aimed to investigate the differences in fruit setting and fruit sensory quality after pollinating these crosses. The results may provide some clues for proportion of pollination trees for cultivation and selection of breeding parents in hybrid breeding of blueberry. 【Method】Using the fruits from open pollination of the female parents as the control (CK), sensory quality indices of hybrid fruits from different crosses including fruit appearance parameters, contents of carbohydrates, antioxidant substances, and volatile compounds were evaluated.【Result】Hybridization compatibility between the three male parents and the rabbiteye blueberry cultivars ‘Vernon’ and ‘Briteblue’ was relatively low. Higher fruit set rate was solely found in the hybrid crosses with highbush types using ‘O’Neal’ and ‘Bonita’ as the male parents. After crossing with ‘O’Neal’, the single fruit mass of ‘Primadonna’ was decreased with a significant increase in fruit firmness. In addition, the fruit shape index of ‘Primadonna’ fruits pollinated by ‘Bonita’ increased significantly. Seed observatioin indicated that the hybrid crosses between blueberry ‘Pink Lemonade’ and three southern highbush cultivars all showed the relatively high fruit set rate, and hybrid seeds were not found in the hybrid fruits in the other crosses. Notably, the hybrid crosses between three male parents ‘O’Neal’, ‘Pink Lemonade’ and ‘Bonita’, and the rabbiteye type cultivar ‘Climax’ all revealed no seeds in the fruits. In comparison with each naturally open-pollinated female parent, the contents of sugar substances in the hybrid fruits of highbush types cultivars were significantly increased after the pollination of ‘O’Neal’ and ‘Bonita’. Especially, the solidity-acid ratios of the hybrid fruits of ‘Winsor’ and ‘Primadonna’ were extremely high after the pollination of ‘Bonita’. Further detection of aromatic substances demonstrated that there was a total of 59 volatile compounds in the fruits of all hybrid combinations. Although the types and contents of the volatile substances varied among the combinations, three main common substances, including linalool, caryophyllene oxide, and trans-2-hexenal were detected across almost all hybrid combinations. The content of linalool in the hybrid fruits of ‘Sharpblue’ was both significantly increased after pollination of ‘Bonita’ and ‘O’Neal’, while that of ‘Primadonna’ was significantly increased only after pollination by ‘O’Neal’. Espcecially, the content of trans-2-hexenal in the hybrid fruits of ‘Primadonna’ and ‘Sharpblue’ pollinated by ‘O’Neal’ was significantly higher than those of the naturally open-pollinated fruits. The volatile substances of the rabbiteye blueberry cultivar ‘Climax’ increased significantly after pollination by ‘Pink Lemonade’, and the substances of alkene type covered a relatively higher proportion. The content of total phenols and anthocyanins showed a similar trend in pollination combinations of different ploidy, with the highest content of total phenols and VC in the hybrid fruits of ‘Climax’ pollinated by ‘O’Neal’, and the content of anthocyanins in the fruit of ‘Primadonna’ and ‘Climax’ was relatively higher under natural open-pollination. 【Conclusion】Blueberries of different ploidy levels have a certain cross-compatibility for inter-ploidy hybridization, and the seedless fruit can be obtained in the crosses of the rabbiteye derived cultivar ‘Pink Lemonade’ and three southern highbush varieties. The solidity-acid ratios of hybrid fruits of most of the highbush cultivars were significantly increased after crossing with the rabbiteye cultivar ‘Bonita’. Especially, after crossing with the male parent ‘O’Neal’, the hybrid fruits of rabbiteye cultivar ‘Climax’ bore no seeds with the increase in the accumulation of antioxidant substances.
【Objective】This research aims to evaluate the fruit characteristics of 46 blueberry cultivars for selection and breeding purposes. 【Method】The fruit appearance, inner quality and sensory properties of 46 blueberry cultivars were investigated, then classified and evaluated by correlation, principal component and cluster analyses. 【Result】The northern highbush blueberry exhibited the largest fruit size, highest and acidity levels, and achieved the highest sensory score. The fruit of southern highbush blueberry was the smallest, with the lowest hardness and sensory score, the highest sweetness and total polyphenol content. The fruit of rabbit eye blueberry was larger than southern highbush blueberry, with the highest pericarp ratio and total anthocyanin content. Among appearance indices, the chromaticity a* of fruit with epicuticular powder removed exhibited the highest coefficient of variation (CV) at 2 926.91%, followed closely by the original fruit chromaticity a* at 370.96%. The CV of solid acid ratio (42.77%) was the highest among quality indices, followed by total anthocyanin content (39.78%), and the CV of sensory score was the lowest (<10%). Correlation analysis revealed that larger fruit size was associated with lower pericarp percentage and total polyphenol content. The acidity had the greatest effect on the solid acid ratio of blueberry fruits. Sensory evaluation indices, including appearance and comprehensive scores, showed significant positive correlations with fruit weight, transverse diameter, and longitudinal diameter, indicating that larger fruit size is a preferred characteristic in sensory evaluation. Cluster analysis showed that the 46 blueberry cultivars were divided into three types, among which the first type had the largest fruit with high hardness and acidity, the second type had the second-largest fruit with the highest sweetness, and the third type had the smallest fruit with high pericarp ratio, belonging to the processing type with high total anthocyanin and polyphenol content. Principal component analysis reduced the 11 appearance and quality indices to four principal components, explaining 75.217% of the total variance. Sensory evaluation revealed that, in addition to differences in size, sweet-sour balance and nutrient content, the 46 blueberry cultivars also varied in wax thickness, texture and fruity aroma, and seven large-fruit cultivars of ‘Primadonna’, ‘Millennia’, ‘Jewel’, ‘Chandler’, ‘Brigitta’, ‘Aurora’ and ‘Prolific’, 3 high sweetness cultivars of ‘Anna’ ‘Sweetheart’ and ‘Brightwell’, and four excellent taste cultivars of ‘Sunshine’, ‘Magnolia’, ‘Brigitta’ and ‘Beckyblue’ were selected. Comprehensive evaluation showed that sensory assessment results were largely consistent with principal component and cluster analyses. 【Conclusion】The 10 cultivars with large fruit size, high sweetness, crisp texture and rich aroma were ‘Prolific’, ‘Chandler’, ‘Sweetheart’, ‘Brigitta’, ‘Millennia’, ‘Beckyblue’, ‘Primadonna’, ‘Brigitta’, ‘Magnolia’ and ‘Pink Lemonade’, which were recommended for fresh consumption, and the 5 cultivars with high total anthocyanins and polyphenols content and high pericarp percent were ‘Gardenblue’, ‘Zhongzhi 4’, ‘Zhaixuan 4’, ‘Baldwin’ and ‘Centurion’, which can be used for processing blueberry products. These cultivars can also serve as parental materials for corresponding breeding objectives.
【Objective】Blueberries (Vaccinium spp.) have garnered significant attention in recent years due to their rich content of bioactive compounds, particularly anthocyanins, which exhibit a wide range of physiological functions, including antioxidant, anti-inflammatory, and lipid-lowering effects. These functional properties make blueberries a valuable fruit for both dietary consumption and potential therapeutic applications. However, significant variations exist in fruit quality and functional component profiles among different blueberry cultivars. Understanding these variations is crucial for the selection of breeding parents, the development of functional food products, and the optimization of post-harvest processing techniques. This study aims to systematically compare the fruit quality characteristics and functional component profiles of ten high-anthocyanin blueberry cultivars, providing a scientific basis for the selection of fresh-eating varieties, the development of functional products, and the identification of superior breeding materials. 【Method】Ten high-anthocyanin blueberry cultivars, including southern highbush, northern highbush, and rabbiteye cultivars, were selected for this study. The fruits were harvested from the experimental blueberry orchard at the Nanjing Lishui Research Base of the Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, during the period from May to July in 2024. The study focused on evaluating the external characteristics (color, fruit diameter, fruit weight and firmness), nutritional components (soluble solids content, total acid content and solid-acid ratio), and functional components (polyphenols, anthocyanins, flavonoids and ellagic acid) of both whole fruits and fruit peels. The content of these components was measured using standardized methods, and correlation and cluster analyses were conducted to comprehensively evaluate the fruit quality. The study aimed to identify the key factors influencing the functional and nutritional properties of blueberries and to determine the relationships between these factors.【Result】Among all the measured indicators, the coefficient of variation for anthocyanin content was the highest (27.16%), followed by total acid content (26.61%), while the variation in soluble solid content was the lowest (2.84%). In terms of functional components, cultivars such as ‘Centurion’, ‘Elliott’, ‘Gardenblue’, ‘Zhaixuan No.4’, and ‘Lanmei No.1’ exhibited higher anthocyanin content. Specifically, ‘Centurion’ had the highest anthocyanin content in the whole fruit (3.09 mg/g), while ‘Elliott’ showed the highest anthocyanin content in the peel (41.92 mg/g). Polyphenol, flavonoid, and ellagic acid contents were significantly positively correlated with anthocyanin content, indicating a close relationship among these functional components. Additionally, the peel mass fraction was positively correlated with the content of functional components, suggesting that thicker peels are associated with higher levels of bioactive compounds. In terms of external fruit characteristics, ‘Brigitta’ had the largest single fruit weight (2.42 g), followed by ‘Brightwell’ and ‘Centurion’. ‘Lanmei No.1’ exhibited the most rounded fruit shape, while ‘Elliott’ had the flattest shape. Cultivars with more abundant fruit wax, such as ‘Bluecrop’, ‘Brigitta’ and ‘Brightwell’, showed higher fruit firmness and better storage performance. The analysis of the soluble solids-to-acid ratio (SSR) revealed that cultivars like ‘Zhaixuan No.4’, ‘Brightwell’, ‘Bluecrop’ and ‘Gardenblue’ had SSR values above 20, indicating a sweeter taste and making them more suitable for fresh consumption.【Conclusion】Among the ten cultivars studied, ‘Centurion’, ‘Elliott’, ‘Gardenblue’, ‘Homebell’ and ‘Zhaixuan No.4’ exhibited high levels of functional components, particularly anthocyanins, making them ideal candidates for the extraction of bioactive compounds and as breeding parents for high-nutrition and health-promoting blueberry varieties. On the other hand, cultivars such as ‘Bluecrop’, ‘Brigitta’ and ‘Brightwell’, with their higher SSR values and superior external qualities, are more suitable for the fresh fruit market. The study also highlighted that thicker peels are associated with higher functional component content, suggesting that cultivars with thicker peels are more suitable for processing and the extraction of bioactive compounds. Furthermore, cultivars with more abundant fruit wax demonstrated better storage performance, providing new insights for post-harvest preservation technologies in blueberries. This study systematically compared the fruit quality of ten high-anthocyanin blueberry cultivars in the Nanjing region, revealing significant differences in functional component content and external characteristics among the cultivars. The findings provide a scientific basis for blueberry breeding and processing, particularly for the selection of high-anthocyanin cultivars and the development of functional products.
【Objective】The purpose of this study is to understand the changes in sugar and other quality indexes during fruit development, to explore the potential mechanism of carbohydrate accumulation during blueberry (Vaccinium spp.) fruit development, and to establish a theoretical foundation for blueberry quality enhancement.【Method】Fruits of six blueberry cultivars at different developmental stages were used as the test materials. The morphological traits (size and color), antioxidant system-related parameters, fruit quality indexes, the expression levels of VcSWEETs genes, and sugar composition and content were determined. The correlation analysis among these parameters was performed using the Pearson correlation model.【Result】With the development of the fruit, the fruits of each cultivar gradually increased in size and deepened in color, of which the ‘Legacy’ cultivar had the largest fruit weight and transverse diameter, and ‘Zhongzhi 2’ had the smallest during the purple fruit stage (S3). In the S3 period, ‘Legacy’ showed peak L value with minimal a* and b* values. The generation rate of O 2 · - and MDA content steadily increased, while H2O2 content (excluding ‘Zhongzhi 4’) and SOD activity decreased first and then increased, and POD activity gradually increased. Total soluble solids (TSS) and anthocyanin contents gradually increased, flavonoid content gradually decreased, and ellagic acid content initially decreased and then increased. Among them, ‘Zhongzhi 4’ had the highest TSS and anthocyanin content during the S3 period. The expression patterns of three VcSWEETs genes exhibited distinct cultivar specificity and developmental stage dependence. Sucrose, glucose, fructose, and total sugar accumulated continuously, though glucose maintained basal levels. In the S3 period, the total sugar contents of all cultivars were more than 200 mg/g, except for ‘Zhongzhi 1’.【Conclusion】Sugar content increased continually during fruit development, with sucrose and fructose concentrations predominating over glucose. ‘Legacy’ had the greatest total sugar content during the S3 period, followed by ‘Zhongzhi 2’ and ‘Zhongzhi 4’. The expansion of the fruit, the rise in anthocyanin content and POD activity, and the up-regulated expression of the VcSWEET1 gene were significantly correlated with sugar accumulation patterns.
【Objective】With the increasing environmental awareness driven by the severe pollution caused by plastic products, this study aims to understand the current research status and advantages of “replacing plastic with bamboo”. It also seeks to clarify the challenges faced in the efficient cultivation of bamboo resources, guide research institutions and enterprises to focus on key technical issues, increase research investment, promote innovation in bamboo cultivation technologies, improve the utilization efficiency of bamboo resources, and enhance the competitiveness of the bamboo industry.【Method】Relevant literatures on “Bamboo as a substitute for plastic” and “Bamboo resources” from the past 15 years (2010-2024) were retrieved from the CNKI and Web of Science Core Collection databases. VOSviewer was used to conduct a visual analysis of the types of bamboo species and research topics currently studied. In addition, a combination of questionnaire surveys and on-site enterprise investigations was employed to identify current issues and challenges in the efficient cultivation and utilization of bamboo in major bamboo-producing areas, based on China’s bamboo resources and industrial advantages.【Result】Over the past 15 years, research on “Bamboo as a substitute for plastic” and “Bamboo resources” has shown a booming trend, with a significant increase in the number of published papers. Research hotspots mainly focus on the biological characteristics of bamboo, as well as the physical, chemical, and mechanical properties of bamboo materials. This article also summarized the advantages of using bamboo as a plastic substitute and highlighted the existing problems in the efficient cultivation of bamboo resources. Suggestions for the future development direction of bamboo resource cultivation were also proposed.【Conclusion】In the future, efforts should be made to build bamboo germplasm resource repositories and cultivate high-value bamboo species for “Bamboo as a substitute for plastic”. Focus should be placed on transforming low-yield and low-efficiency bamboo forests, and establishing high-standard bamboo forest demonstration areas based on local conditions. Scientific planning and improvement of infrastructure—such as roads, water storage, and irrigation systems—in bamboo forests are essential. Additionally, it is necessary to innovate high-quality raw material supply chains and adopt advanced management models for bamboo forests. These initiatives will play an important role in promoting ecological civilization, driving social and economic development, implementing the rural revitalization strategy, and achieving the goals of “Carbon Peaking and Carbon Neutrality”.
【Objective】Internode length is a crucial trait for bamboo industrial utilization. Pseudosasa japonica var. tsutsumiana is a stable dwarf mutant of P. japonica, characterized by shortened, flask-shaped internodes, making it an ideal material for studying internode growth in bamboos. Preliminary studies identified the GRAS transcription factor PjGRAS56 as a key candidate gene responsible for the shortened internode formation in P. japonica var. tsutsumianais. This study aims to elucidate the potential role of PjGRAS56 in bamboo internode development.【Method】We employed bioinformatics to analyze the sequence features of PjGRAS56, confocal laser scanning microscopy to observe its subcellular localization, a yeast transcription system to assess its transcriptional activation activity, transgenic techniques in rice and Arabidopsis to analyze phenotypes of PjGRAS56-overexpressing plants, transcriptome sequencing and qRT-PCR to examine gene expression changes, and hand-sectioning to measure internode cell length.【Result】PjGRAS56 localized to the nucleus and cytoplasm, and lacked transcriptional activation activity. It was significantly down-regulated in the division zone of P. japonica var. tsutsumianais internodes. Overexpression of PjGRAS56 in rice resulted in dwarfism, shortened internodes, reduced tillering, shorter panicles and awns, fewer grains, and reduced leaf angle; overexpression of it in Arabidopsis led to smaller leaves and shorter flower stalks. Although the cell length in internodes of PjGRAS56-overexpressing plants was similar to controls, the cell number was significantly reduced. Transcriptome sequencing and differential gene expression analysis revealed significant down-regulation of cell division-related genes in PjGRAS56-overexpressing plants.【Conclusion】PjGRAS56 is a putative negative regulator of internode growth in bamboo.
【Objective】This study aimed to examine the dynamic characteristics of moso bamboo (Phyllostachys edulis) stands subjected to strip-shaped clear-cutting and to provide insights into the development of appropriate scientific management strategies for moso bamboo forests.【Method】A strip-shaped clear-cutting experiment was conducted in pure moso bamboo stands within the Forest Farm of Yixing, Jiangsu Province. The size of strip-shaped clear-cutting plots (SC) is 20 m×8 m for each. In addition, three reserved plots (RB) of the same dimensions were positioned on both sides of the clear-cutting plots. For comparison, three 20 m ×20 m control plots (CK) were set up under traditional management practices. The study investigated the dynamics of moso bamboo shoot development, the growth of new bamboo, and changes in soil nutrient content across the different treatment plots over five years following the strip-shaped clear-cutting. Pearson correlation analysis was applied to assess the relationship between soil nutrient factors and stand characteristics.【Result】(1) In the first year following clear-cutting, the number of bamboo shoots in the SC plots increased by 71.17% compared with RB and by 62.21% compared to CK, while the number of new bamboo grew by 38.97% in SC relative to RB and 55.07% relative to CK. (2) In the first year, the mean diameter at breast height (DBH), mean height to crown base (CBH), and mean height (H) of new bamboo in SC were significantly lower than those in CK (P<0.05). By the fifth year after clear-cutting, the DBH, CBH, and H of new bamboo in SC surpassed those in CK, with a significant increase in CBH (P<0.05). (3) Strip-shaped clear-cutting significantly reduced the total soil nutrient content in SC plots (P<0.05), while enhancing the content of quick-acting nutrients in both SC and RB plots; however, these differences were not statistically significant. The soil organic carbon content in SC was lower than in CK and RB, although the difference was not significant. By the fifth year after clear-cutting, there was no significant difference in soil nutrient content between SC and RB when compared to CK. (4) Correlation analysis revealed a highly significant negative relationship between the number of shoots in SC and the soil’s alkaline nitrogen (AN) and quick-acting potassium (AP) content (P<0.01). Similary, the number of new bamboo exhibited significant negative correlations with both soil AN and AP content (P<0.05). Conversely, the quality characteristics of the new bamboo were significantly positively correlated with soil total potassium content (P<0.05).【Conclusion】Strip-shaped clear-cutting enhances bamboo shoot density and the formation of new bamboo in moso bamboo forests but negatively impacts the quality of new bamboo. It leads to a reduction in total soil nutrient levels and an increase in quick-acting nutrients. As the bamboo stands recover, the quality of the new bamboo gradually improves, and soil fertility is restored. By the fifth year after clear-cutting, the stand characteristics of the moso bamboo forest in the SC plots return to levels similar to those in the CK plots.
【Objective】Rapid industrialization and urbanization under climate change have intensified atmospheric pollution across many regions of China. Ozone(O3), a phytotoxic secondary pollutant with increasing concentrations, has become a major summer time air pollutant in urban areas, posing serious threats to ecological security. Leaves of different ages may exhibit varying sensitivity or responses to atmospheric ozone (O3) pollution, and the physiological mechanisms underlying age-related differences in photosynthetic responses remain to be fully elucidated. This is crucial for a comprehensive understanding of the response mechanisms of bamboo species to atmospheric O3 pollution. This study investigated the effects of elevated O3 concentration(eO3) on the urban landscaping bamboo species Indocalamus decorus to assess whether leaf age influences the O3 resistance of I. decorus, and to elucidate the mechanistic links between chlorophyll fluorescence parameters and photosynthetic impairment.【Method】Nine open-top chambers (OTCs) were established with three O3 treatments in a suburban area of Changping District, Beijing. The OTCs, constructed with aluminum alloy frames and covered with 10 mm thick transparent plastic film (90% light transmittance), were 2.5 m in height and 2 m in diameter, with a ground area of 3.14 m2 and spaced 2 m apart. I. decorus, a small evergreen ornamental bamboo with significant economic value in China and broad applications as a sustainable “bamboo-as-plastic” substitute, was selected as the study species. It is commonly used in food packaging, temporary shelters, boat canopies, hat weaving, and textile manufacturing. Rhizomes of uniform age (five years), color, and thickness were selected, and 10 cm segments with consistent length and bud number were propagated. After one year, uniform seedlings were transplanted for the experiment. During the growing season, chlorophyll content, gas exchange, and chlorophyll fluorescence parameters were measured in both mature and newly emerged leaves. In view of rising O3 levels in Beijing and the known O3 tolerance of I. decorus, the O3 treatments included ambient air (AA), AA + 70 ×10-9 O3 (AA+70), and AA + 140 ×10-9 O3 (AA+140). O3 fumigation was conducted daily from 8:30 to 17:30 (9 h), starting on June 1st and ending on October 12th.【Result】(1) SPAD values of old and new leaves exhibited contrasting responses to O3. Under AA+70 and AA+140 treatments, SPAD values of old leaves decreased by 10.5% and 7.8%, respectively (P<0.05), whereas SPAD values of new leaves increased by 6.3% under AA+140. A significant interaction between eO3 and leaf age was observed, with eO3 amplifying SPAD differences between leaf ages. (2) eO3 significantly reduced the maximum photosynthetic rate (Asat) and stomatal conductance (Gs) of older leaves under saturating light, but had no significant effects on younger leaves. The photosynthetic decline in older leaves was primarily attributed to non-stomatal limitations.(3) eO3 significantly decreased the actual quantum yield of PSⅡ (ΦPSⅡ), quantum efficiency of CO2 assimilation (PhiCO2), and electron transport rate (ETR) in both young and old leaves, with more pronounced reductions in older leaves. Additionally, eO3 reduced both photochemical quenching (qP) in young leaves. A significant interaction between eO3 and leaf age on PhiCO2 was observed, indicating that eO3 exacerbated the differences between young and old leaves.【Conclusion】Elevated O3 concentration induces chlorophyll degradation and PSⅡ photodamage in mature leaves, suppressing light reactions (reduced ΦPSⅡ) and electron transport (lowered ETR), thereby impairing photosynthesis. In contrast, new leaves exhibit compensatory mechanisms: preferential allocation of resources (e.g., photoassimilates and antioxidants) helps stabilize chlorophyll content and maintain Asat, sustaining overall photosynthetic performance. This leaf-age-dependent resource allocation strategy—prioritizing younger leaves—enhances population-level O3 tolerance in I. decorus, underscoring its ecological adaptability and reinforcing its potential as a sustainable “bamboo-based plastic alternative”. Future studies should investigate the long-term effects of O3 on chlorophyll fluorescence dynamics to better understand photosynthetic acclimation. This study provides precise data and theoretical support for understanding the impacts of air pollution on bamboo growth, offers a scientific foundation for the development of eco-friendly and sustainable bamboo industries, and contributes predictive insights into the effects of future climate change on urban green vegetation.
