十个歪头菜居群遗传多样性分析

Genetic diversity of ten Vicia unijugapopulations by ISSR markers

采用ISSR分子标记对10个歪头菜自然居群的104个样本进行遗传多样性分析,筛选的10条ISSR引物共扩增出115个位点,其中多态性位点110个。在物种水平上多态性比率（PPB）为95.65%,在居群内多态位点比率为24.35%~49.70%。POPGENE分析结果显示,物种水平上Nei’s基因多样性（H）为0.2632,Shannon’s遗传多样性信息指数（I）为0.4046,基因流（Nm）为0.4553,基因分化度（Gst）为0.5283,AMOVA分析居群间遗传分化程度为50.51%。研究表明,10个采样点的歪头菜在物种水平上具有较高的遗传多样性,但在居群之间已经出现了一定程度的遗传分化,且居群间的遗传分化程度高于居群内的分化程度。同时,证明了环境压力大小对于遗传多样性的高低具有选择作用,环境压力小的烟台和环境压力大的合作地区具有较高的遗传多样性,但环境压力介于二者之间的地区遗传多样性水平相对较低。本研究结果不仅对于了解歪头菜遗传进化和其生长地的环境的关系具有重要的参考价值,对合理利用歪头菜遗传资源及育种还具有非常重要的作用。

Inter-simple sequence repeat （ISSR） markers were used to investigate the genetic diversity within and among ten natural populations of Vicia unijuga. Ten ISSR primers generated 115 discernible DNA bands, of which 110 （95. 65%） were polymorphic. On average each primer produced 11.5 bands, including 11 polymor- phic bands. At the species level, high genetic diversity was detected--PPB （percentage of polymorphic loci） ： 95.65%~ Nm （gene flow）： 0.4553; Gst （genetic differentiation coefficient）： 0.5283; Hs （gene diversity in subdivided populations）i 0. 2632. However, relatively low genetic diversity existed within populations; the percentage of polymorphic loci rate ranged from 24.35 % to 48.70 G. A relatively high level of genetic differen- tiation among populations was revealed by Shannon＇s information measure （0. 4046） and analysis of molecular variance （AMOVA, 0. 5051）.~ The results showed that the ten populations of V. unijuga had high genetic di- versity, but among the populations a certain degree of genetic differentiation had occurred： the genetic differen- tiation among populations was higher than within populations. The results suggest that environmental pressure has a selective relationship with genetic diversity. Low environmental pressure in Yantai and high environmen-tal pressure in Hezuo regions were associated with high levels of genetic diversity, but in the medium pressure regions there was low genetic diversity. This study suggests an important relationship between V. unijuga ge- netic evolution and the environment and can also be used as a reference for working with genetic resources and breeding.