| Cyclocarya paliurus,native to China,is a multi-function tree species with medicinal,timber and ornamental values,and has a great development potential.However,natural forest resources are scarce,mostly scattered in deep forests and nature reserves,and the destruction of the environment and over-harvesting have severely affected the sustainable development of C.paliurus industry.The full exploitation and use of the germplasm resources of C.paliurus and the creation of plantation forests can effectively solve this problem.Therefore,in this study,the 19 grafted clones selected from superior individual trees of C.paliurus were used as test materials to analyze and explore the genotypic differences in growth traits,leaf traits,light use efficiency,content and yield of major bioactive compounds among the different clones.The aims of this study are to screen out the good asexual lines suitable for use in Nanjing and surrounding areas with similar climate,accelerate the process of exploitation,utilization and industrialization,and to provide a theoretical basis for breeding and popularization of C.paliurus.The main results are as follows:(1)There existed significant variations in the annual growth of young tree height and leaf biomass(p < 0.05),indicating a high degree of variation and genetic diversity.Of them,clone Q4 showed the best growth performance.Significant differences in leaf morphology characteristics(leaf shape and leaf color)and leaf anatomical structure of different clones were also observed between June and September(p < 0.05).The LC1 had larger leaf area,smaller total leaf thickness and specific leaf weight,and its leaf color was reddish.However,clones Q4 and Y1 showed relatively larger total leaf thickness and palisade tissue thickness.(2)Significant variations were observed in photosynthtical traits among the C.paliurus clones(p < 0.05).Combining the performances of different clones in fluorescence yield,energy conversion efficiency and photosynthetic performance index,energy distribution ratio and PSII reaction center specific activity,LS2,Q4 and Y1 had higher light energy use efficiency and modulation ability.(3)There were significant variations in the leaf contents of bioactive compounds between June and September among different clones(p < 0.05),as well as in the yield of bioactive compounds(p < 0.05).Based on the content of bioactive compounds in different growing seasons,clone L1 had higher contents of total polyphenol and phenolic acid in both growing seasons,LC1 had the highest contents of total flavonoid,and BA1 and CR6 had the highest contents of total triterpenoid,but the CR5 showed a higher content of water-soluble polysaccharide both in June and September.Meanwhile,the highest yield of all bioactive compounds was observed in clone CP3.(4)Pearson correlation analysis showed that growth,leaf morphology and contents of bioactive compounds were correlated to a certain extent.Therefore,the phenotypic traits,such as growth traits and leaf morphology characteristics,could be used as important references for the selection of superior germplasm of C.paliurus during the selection process.(5)A total of 2 superior clones with high polyphenol contents and accumulation,5 superior clones with high and stable flavonoid contents and accumulation,3 superior clones with high and stable total triterpenoid contents and accumulation and 2 superior clones with high and stable polysaccharide contents and accumulation were preliminary selected according to the targeted breeding objectives,(6)By principal component analysis and membership function method,4 clones(LC1,LF1,L1 and CP3)with superior and stable comprehensive performance were selected as leaf production for further experimental research.In addition,clones CP3,CR6,Q4,LC1 and LC4 were selected as superior clones for the production of bioactive compound accumulations.Therefore,LC1 and CP3 were recommended as the best clones for leaf use. |
PDF Full Text Request