Genetic diversity and differentiation of two ecotypes of Leymus chi-nensis populations in microhabitat--Allozyme analysis
微生境下羊草两种生态型种群的遗传多样性及遗传分化——等位酶分析

Leymus chinensis (Trin.) Tzvel.is a rhizome grass species,which has two ecotypes,a gray green type and a yellow green type,in the south of the Songnen Plain of China.Levels of allozyme diversity and genetic differentiation were assessed for 14 allozyme loci in 7 populations of the gray green type and 2 populations of the yellow green type (a total of 271 individuals). Leymus chinensis maintained relatively high genetic variation at the ecotype,population and species levels as compared with the average plant species.Significant differences of genetic diversity and genetic differentiation were found between the gray green and yellow green ecotypes.Percentage of polymorphic loci,mean number of alleles per locus and expected heterozygosities between the gray green type and the yellow green type were 67.3% and 57.1%,2.2 and 1.9,0.348 and 0 298 respectively.The means of genetic distance were 0.18 between the ecotypes,0 045 and 0 099 within the gray green type and the yellow green type respectively.While the means of genetic identity were 0 836 between the types,those within the gray green type and the yellow green type were 0 956 and 0 914 respectively.