珙桐遗传多样性的AFLP分析

Genetic Diversity of the Endangered Davidia involucrata by AFLPAnalysis

采用7对AFLP引物对中国珍稀濒危植物珙桐（Davidia involucrata Baill.）的6个天然居群和2个人工居群的229份材料进行扩增,共检测到100~500bp的位点506个,其中多态性位点488个,多态性位点百分率96.44%;各居群多态位点百分率为52.77%~79.25%,平均为67.00%。在物种水平上,珙桐的Nei’s基因多样性Hs=0.3429,Shannon’s遗传多样性信息指数I=0.5107。而居群水平上,各居群的Nei’s基因多样性介于0.2229~0.3389,各居群的平均Nei’s基因多样性Hs=0.2748,各居群Shannon’s遗传多样性信息指数（I）介于0.3219~0.4877,平均Shannon’s遗传多样性信息指数I=0.3995。居群间基因间分化度（Gst）为21.60%,基因流Nm为1.8。说明珙桐的遗传多样性较高,这8个居群间存在一定的遗传分化和基因流动,但遗传分化主要存在于居群内。在珙桐与其变种光叶珙桐之间未找到差异标记。

We analyzed the genetic diversity of six natural and two artificial populations of the endangered plant species,Davidia involucrata Baill. using the AFLP method. A total of 506 reproducible bands of 100–500 bp were obtained with seven AFLP primer combinations,of which 488 bands were polymorphic with a proportion of 96.44%. The percentage of polymorphic bands in different populations ranged between 52.77%–79.25% with an average of 67.00%. At the species level,the Nei’s genetic diversity（Hs）is 0.3429,and the Shannon’s information index（I）is 0.5107;At the population level, the Nei’s genetic diversity ranged from 0.2229 to 0.3389 with an average of 0.2748,and the Shannon’s information index from 0.3219 to 0.4877,averaging 0.3995. The differentiation coefficient（Gst）among the populations was 21.60% and the gene flow（Nm）1.8. The results showed that there was a high genetic diversity in D. involucrata,and genetic differentiation and gene flow were found between the eight populations,but the genetic differentiation occurred mainly within each population. No molecular markers were found between D. involucrata and D. involucrata var. vilmoriniana.