GENETIC DIVERSITY AND MATING SYSTEM OF CAMELLIA TUNGHINENSIS CHANG EXTREMELY SMALL POPULATION

摘要

Camellia tunghinensis chang is an evergreen shrub or small tree of Sect. Chrysantha of Theaceae is endemic to Guangxi and has been listed as a national second-class protected plant. Genetic diversity and mating system of 4 Camellia tunghinensis chang w ild mother and offspring populations (214 individuals in total) were analyzed by SSR m olecular marker. The results show that the genetic diversity of the mother generation and the offspring of the w ild population of Camellia tunghinensis chang is relatively high (the mother population 1=5.250,=0.830,e=0.681，=1.351; the offspring population A/a=6.125，0= 0 .0 .8 4 5 =0.698，/=1.433). M LTR was used to analyze the mating system of parent and offspring of 4 populations (M ZT, MJG, SHL, DLG ) of Camellia tunghinensis chang, and to analyze the parameters of m ultiple sites heterocrossing rate, unit heterocrossing rate and inbreeding number of each population. The results showed that the heterozygosity at m ultiple points and heterozygosity at unit point of 4 populations were relatively high (tm=0.965, t s=0.885). There is a great difference between rt and rpm, which indicates that sub-population structure exists in populations. The outcrossing of the populations is m ainly carried out between in dividuals in the sub-populations, and it is d iffic u lt for the subpopulations to undergo gene flow and d iffe rentiation. The results reveal the mating pattern of Camellia tunghinensis chang, analyze its genetic diversity and genetic differentiation, and provide a prediction for the protection measures and breeding.