The Succession Of Population Structure And Mating Pattern Of Different Populations In Sinocalycanthus Chinensis

Sinocalycanthus chinensis (Cheng et S.Y. Chang) Cheng et S.Y. Chang belongs to Calycanthaceae and Sinocalycanthus, It’s the third century relict plant, mainly distributed in narrow area of Zhejiang province Chinese (Lin’an city and Tiantai County).Sinocalycanthus chinensis has high requirements to the habitat,it prefers moist environment and scattered light,either too much shades or direct light can lead to poor growth and serious degeneration;for the special requirements of habitat, Sinocalycanthus chinensis is sensitive to the changes of characteristics of community and conditions of habitat.Therefore, in order to analysis of mating patterns of different populations and their genetic effect then discuss about the contact of community characteristics, population structure, mating system and genetic diversity, which lays a theoretical foundation for the protection and utilization of Sinocalycanthus chinensins, this study starts from structure analysis of populations and communities, combined with artificial mating experiments and evaluation of genetic diversity.Survey of population and community structure:population and community characteristics of12populations in Tian Tai county, Ling An city and Ji Xi county in An Hui province were investigated with site-plot methods in this paper. The results show that due to the implementation of national forestry policies (reforestation, protection of natural forests and the establishment of nature reserves, etc.) as well as changes in the distributions of S. chinensis forest business model different communities with S. chinensis population development through its own evolution for the different stages which produce significantly different effects to the growth of S. chinensis. DMS, XK, BSW and DJK population are relatively stable by their community types and their communities stay in tree stage or top tree stage which means their habitat is relatively stable and all species achieve balance through competition in a long time. ZY and XGP population belong to serious recession populations,their communities experienced the evolution from shrub stage to shrub and tree stage,the original level of evergreen trees which is in the same shrub layer with S. chinensis gradually formed intensive tree layer that results in poor growth and even death of S. chinensis lacking seedlings or number then S. chinensis gradual degradation in this region because of difficulties in updating and will eventually disappear.The community which LTS population stays is in the early stage of community evolution, it’s in the recession and will gradually degrade without interventions of human. while although SSB and JGP population is now crowded and updating good,but it’s the most variable populations once the human interventions increase or eliminate their population structure will change rapidly and it’s going to extinction to a great chance.Artificial mating experiments:on the basis of population surveys, choose3different types of populations (JGP, XK and SSB) to do artificial pollination experiments. The results indicates that seed set rate, seed set number, single flower average seed number of different ways of pollination, are significantly different. Different ways of Pollination and interaction between different ways of Pollination and different ways of Pollination produce significant affect to seed set rate, seed set number and flower breeding flower breeding average seed number. There are significant difference between SSB and XK population. At the aggregate level, various types of single flower breeding average seed number ranking:outcrossing between isolated populations> outcrossing between neighboring populations> outcrossing within population> geitonogamy> natural pollination. The order of average seed number born by one flower of JGP population is:outcrossing among outbreeding populations> outcrossing within population> geitonogamy> natural pollination. The order of average seed number born by one flower of XK population is:geitonogamy> outcrossing within population> outcrossing among isolated populations>Natural pollination> outcrossing among neighboring populations. The order of average seed number born by one flower of SSB population is:outcrossing among isolated populations> Natural pollination> geitonogamy> outcrossing within population. The reproductive success rate of outcrossing among isolated populations is high in various populations.Evaluation of genetic diversity:genetic diversity of S. chinensis is analyzed by SRAP molecular marker, genetic analysis shows that high genetic diversity on the level of species and low genetic diversity on the level of population. AMOVA analysis shows that55.01%genetic variation of S.chinensis stay among populations and44.99%of the genetic variation within populations. Genetic differentiation coefficient of S. chinensis was0.5174that means genetic differentiation among populations, gene flow among populations is small by the number of0.4663.Genetic differentiation of S.chinensis is high in space but low in time scale.