Studies On Population And Genetic Diversity Of Wild Chimonanthus Praecox In Baokang County

As there are large quantities of Chimonanthus praecox widely distributed in Baokang County of Hubei Province, the county is named "the kingdom of wintersweet". Population and genetic diversity of wild Chimonanthus praecox in Baokang County were studied in this paper.1. Through the study on 8 wild Chimonanthus praecox populations in Baokang County, this paper found out that the abundance(88), importance value(28.92) and frequency(100%) of Chimonanthus praecox were the highest among all species of basekage. Chimonanthus praecox held the superiority position in all populations. The species richness(28), Simpson's index(0.84) and Shannon-Winner's diversity index (1.06) of the Citangou wild Chimonanthus praecox population are higher than those of the other populations.2. Through the study on genetic diversity of wild Chimonanthus praecox in Baokang County, this paper found out that:When DNA was extracted using CTAB methods, after vibration in 65℃water bath and two extractions, concentration and OD₂₆₀/OD₂₈₀ value of flower total genome DNA were at similar standard to those of leaf total genome DNA.The optimum ISSR reaction system of Chimonanthus praecox was every 20μL reaction system containing 1×PCR buffer , 2.4mmol·L^-1MgCl₂,0.4μmol·L^-1 primer, 20 ng DNA template, 0.5U Taq DNA polymerase and dNTP0.5μmol·L^-1.The percentage of polymorphic bands was 64.56% when 8 pairs of primers were used to amplificate respectively the genomic DNA of 12 wild Chimonanthus praecox individuals. UPGMA cluster analysis indicated that the wild Chimonanthus praecox individuals with similar flower type and flower color were clustered first.When 10 pairs of primers were used to amplificate respectively the genomic DNA of 60 different wild Chimonanthus praecox individuals in 5 popolations, the percentage of polymorphic bands was 52.48%. The among-population component accounts for 21.72% of the totle variation, while the within-population component accounts for 78.28%. Shannon's information and index and Nei's gene diversity of Qilibian population were the highest of all populations, while the Moshan population in Donghu was the lowest. UPGMA cluster analysis indicated that the Ziweiyuan population and Qilibian population were clustered first and then clustered into the first group with Citangou population, while the Jiguling population and the Moshan population in Donghu were clustered into the second group.