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Effects of substrates and rooting regulators on rooting of cuttings in Manglietia conifera Dandy ZHAO Xiang, LI Qingying, JIANG Qingbin, ZHONG Chonglu, ZHANG Jie JOURNAL OF NANJING FORESTRY UNIVERSITY    2019, 43 (02): 23-30.   DOI: 10.3969/j.issn.1000-2006.201805051 Abstract （1975）      PDF（pc） （2347615KB）（1295）       Knowledge map    Save 【Objective】In southern China, Manglietia conifera Dandy trees flower normally; however, seed production is extremely low. Even if a small number of seeds can be obtained, the seeds are deformed and the quality of seedlings is poor. These conditions limit the cultivation and utilization of this species. Cutting propagation is an effective method for rapid propagation of many tree species. However, this propagation technique has not previously been examined for M. conifera in China. This research aimed to determine suitable growing medium and appropriate root hormone type, concentration, and treatment time through the utilization of different substrates and hormones to treat softwood cuttings. 【Method】The middle and upper plant segments, approximately 8-10 cm in length, from one-year-old branches were used as cutting materials. Each cutting had the terminal bud removed and consisted of three upper leaves with a quarter area of each leaf being retained. In order to study the influence of different substrates, the cuttings were treated with ABT-1 of 1 000 mg/L rooting solution for 10 s and planted in ten different substrates including peat, vermiculite, perlite, yellow soil, river sand and mixtures by volume of 1:1 perlite and vermiculite, 1:1 perlite and peat, 3:1 perlite and peat, 1:1 peat and vermiculite, and 3:1 peat and vermiculite. For the purpose of studying the effect of different types and concentrations of hormones with treatment time, the experiment was conducted using an orthogonal design L9 (33), and the cuttings were treated with either ABT-1, IBA, or IAA solutions at three concentration gradients(500, 1 000 and 1 500 mg/L)for 10 s, 1 min or 30 min, and inserted into substrate of 3:1 peat and vermiculite by volume. Observations were made on the formation of callus tissue and emergence of roots. Four months after the treatments, cutting seedlings were transplanted into pots. Rooting rate, number of roots, mean root length, and the longest root length were counted and calculated. The effect of rooting was comprehensively evaluated by the root effect index. Data were analyzed using SPSS 20.0, and Duncan's Multiple Range Test was used to determine significant differences between treatment means.【Result】The rooting process of cuttings could be divided into four stages as follows: ① 0-15 d, cut wounds were healed and callus tissue formed; ② ≥15-40 d, callus tissue gradually increased; ③ ≥40-60 d, adventitious roots originated from the bark and also callus tissue; ④ following 60 d, a great deal of adventitious roots were generated. Roots were mainly induced from the bark but could also develop from callus tissues. A medium mixture of 3:1 peat and vermiculite by rolume was the optimal substrate with 47.92% rooting rate, average root length of 5.20 cm, mean number of roots 8.03, and the root effect index 1.310. The orthogonal test showed that the primary and secondary sequence of factors was treatment time, type of hormone, and concentration of hormone. The most effective hormone treatment for rooting was 1 000 mg/L IBA with treatment time of 10 s. The average length of roots was 5.53 cm, the number of roots was 5.6, the rooting rate of cuttings was 51.07% and the root effect index was 0.972.【Conclusion】This study demonstrated that M. conifera can be propagated by rooting of cuttings taken from one-year-old branches. Roots were mainly induced from the bark but also from callus tissues, and compound substrates were more effective than individual substrates. Further research should be carried out to better understand the technical aspects of cutting propagation for mass production of M. conifera seedlings. Reference | Related Articles | Metrics | Comments（0）

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Plant regeneration of Salix suchowensis through tissue culture SUN Yonglian, DAI Xiaogang, LI Xiaoping, CHEN Yingnan JOURNAL OF NANJING FORESTRY UNIVERSITY    2019, 43 (02): 31-37.   DOI: 10.3969/j.issn.1000-2006.201801034 Abstract （1700）      PDF（pc） （1745525KB）（1227）       Knowledge map    Save 【Objective】In this study, we aimed to establish an efficient plant regeneration protocol for Salix suchowensis through tissue culture, which would serve as a foundation for developing a genetic transformation system for this woody shrub. 【Method】By using young stems with axillary buds and mature seeds as explants, the influences of different factors on plantlet regeneration were systematically studied, including sterilization methods, types of the basic medium, light conditions, and plant growth regulators. 【Result】The optimal basic medium for S. suchowensis was Murashige and Skoog(MS)medium + sucrose(30 g/L)+ Phytagel(4.4 g/L). When using young stem nodal segments as explants, the best sterilization method was 70% ethanol for 30 sec and then 20% sodium hypochlorite for 10 min, while the optimal medium for axillary buds induction and multiplication was the basic medium supplemented with 6-BA(1 mg/L)+ NAA(0.01 mg/L)and 6-BA(0.5 mg/L)+ NAA(0.05 mg/L), respectively, and the appropriate medium for rooting was the basic medium + IBA(0.2 mg/L)+ NAA(0.03 mg/L). While for mature seeds, the optimal sterilizing treatment was 70% ethanol for 10 sec and then 20% sodium hypochlorite for 2 min; the appropriate medium for callus indution, proliferation and subsequent shoot differentiation was the basic medium supplemented with 6-BA(0.5 mg/L)+NAA(0.3 mg/L), 6-BA(0.5 mg/L)+ NAA(0.5 or 0.8 mg/L), 6-BA(0.5 mg/L)+ TDZ(0.2 mg/L), respectively, and the best rooting medium was the basic medium containing NAA(0.01 mg/L). 【Conclusion】We established a regeneration protocol for S. suchowensis from the axillary buds or callus by using young stem nodal segments and mature seeds as explants respectively. Reference | Related Articles | Metrics | Comments（0）

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Environment-dependent phenotypic variation of Osmanthus fragrans ZHENG Sunyuan, ZHU Hong, JIN Siyu, WANG Mengjuan, SUN Jie, GU Chengcheng, PEI Yinwei, WANG Xianrong, DUAN Yifan JOURNAL OF NANJING FORESTRY UNIVERSITY    2019, 43 (02): 38-46.   DOI: 10.3969/j.issn.1000-2006.201808039 Abstract （1745）      PDF（pc） （1924663KB）（1169）       Knowledge map    Save 【Objective】Reveal the phenotypic diversity and geographical variation patterns of Osmanthus fragrans.【Method】Cluster analysis variance analysis and correlation analysis were used to study the leaf phenotypic traits of 26 O. fragrans populations, the flower phenotypic traits of 9 O. fragrans populations, and their variability and correlation with geographical-climatic factors. 【Result】The phenotypic traits of O. fragrans were variable and there were differences in the degree of variation of the eight leaf characteristics. According to the results of the analysis of variance, the phenotypic variation was 75.04% among populations and 13.28% within populations. The main source of variation was from among the populations. In terms of the regions, the average coefficient of variation was 19.08%, and the largest coefficient of variation occurred in the Guihua Town population(29.73%)from the Hubei Province, while the Fuziba population from the Guizhou Province was the smallest(13.68%). In terms of floral phenotypes, the number of inflorescences and pedicels showed the greatest degree of discrepancies. O. fragrans has significant or extremely significant correlations with seven environmental impact factors, such as the latitude, longitude, temperature seasonality, and max temperature of the warmest month. There was a significant or extremely significant correlation between all types of traits. The apex angle of the leaves showed a trend of decreasing from west to east, while the petal traits showed an increasing trend from south to north. The cluster analysis results showed that 26 populations could be clearly divided into 3 groups.【Conclusion】There is a high degree of variation and a rich diversity in the phenotypic traits of O. fragrans. Additionally, O. fragrans are closely related to geo-climatic factors. These results can lay the foundation for the protection and innovation of O. fragrans germplasm resources. Reference | Related Articles | Metrics | Comments（0）

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The population structure, dynamics features and protection strategy of Acer catalpifolium extremely small population XU Heng, LIU Yanhong JOURNAL OF NANJING FORESTRY UNIVERSITY    2019, 43 (02): 47-54.   DOI: 10.3969/j.issn.1000-2006.201803040 Abstract （2206）      PDF（pc） （1507749KB）（1177）       Knowledge map    Save 【Objective】We analyze the age structure and dynamic characteristics of Acer catalpifolium, a unique endangered species in China, reveal the relationship between A. catalpifolium populations and their environment, predict the patterns of population dynamics, explore its endangered mechanism, and propose protection and restoration strategies for wild populations.【Method】A. catalpifolium trees in Emeishan and Dujiangyan, Sichuan Province were studied by field investigation, the method of sample square survey was adopted. The sample area were divided into 1 to 4 samples square of 20 m × 20 m, and then each sample square was divided into 16 small squares of 5 m × 5 m. The A. catalpifolium in the sample square were investigated per wood, investigation content includes some growth factors such as the number of individuals, height of tree, DBH(diameter at breast height), and some habitat factors were recorded such as altitude, latitude, longitude, slope direction, slope, forest canopy density, soil type and vegetation community, the DBH of A. catalpifolium was used to represent age class to reflect the population structure, the DBH size of A. catalpifolium was divided into 11 diameter classes(Ⅰ—Ⅺ; DDBH>50 cm is grade Ⅺ, and the interval of each stage is 5cm), the age class corresponds to the DBH class. The diameter class structure chart was drawn, time-specific life table of the population and important parameters(survival curve and mortality curve)were built and analyzed, the population dynamics were predicted by time series model.【Result】The populations of A. catalpifolium in Emeishan and Dujiangyan were significantly different, there are 105 individuals in Emeishan population and 81 individuals in Dujiangyan population, the age class structure of the population was complete. The diameter class structure of A. catalpifolium showed a spindle-shaped structure with a large proportion of middle age grade and a smaller proportion of young age grade and old age grade. The dynamic change index of population age structure of A. catalpifolium showed that the population age structure dynamic index under random disturbance(Vpi')were 0.011 6 and 0.004 2, respectively, both of which were close to 0. It was showed that the populations were converting from decay-type to decline-type structure. According to the life table, the early death rate of A. catalpifolium was higher than other age, the survival rate were decreasing with age class increased, and the selection effect of the environment was strong. The survival curve were tend to Deevey-Ⅱ, and the mortality was similar in each age level. The survival function analysis showed that the survival rate function S(t) of the two populations presented a monotone decreasing trend with the increase age level, while the cumulative mortality rate F(t) presented a monotone increasing trend, and the changes of the two function curves were complementary. The time series predicted that the number of saplings decreased with old trees increasing gradually. It may difficult to remain the stability of the population for a long time after more trees grow in the 2, 4, 6, 8 age groups in the future. If the seedlings in the population are difficult to supplement, and saplings are not sufficient, the population of A. catalpifolium will become a declining population after 4 years of age.【Conclusion】The biological characteristics and human interference may be the key factors which had made A. catalpifolium endanger, the protection of the population and habitat of A. catalpifolium should be strengthened, the existing adult individuals of A. catalpifolium should be protected, promote the germination of seeds and the renewal of seedlings, and prevent the destruction of habitat and ecosystem. In order to improve germination rate and seedling formation rate of A. catalpifolium seeds, promote seedling conversion rate of A. catalpifolium seeds, the biological characteristics and breeding of A. catalpifolium should be further studied. In addition, artificial cultivation and other measures should be taken to strengthen the protection of individuals and habitats of middle and small diameter A. catalpifolium population in the regeneration of natural forest, so as to promote the natural regeneration and recovery of A. catalpifolium population. Reference | Related Articles | Metrics | Comments（0）