Abstract:

Accessions from Hunan and Hubei provinces in the Chinese soybean pre-core collection were analyzed with SSR markers to determine an optimal strategy in genetic diversity evaluation. The results showed that when analyzed with the same sampling ratio, the number of alleles in accessions from Hubei province was higher than those from Hunan province, however the difference was not up to significant level in genetic diversity index. When analyzed with same sample size by random sampling, accessions from Hunan province were higher both in number of alleles and diversity index than those from Hubei, while there was no significant difference between them as sampled based on cluster. Accessions from Hubei were larger in number of alleles than those from Hunan when sampled by the same genetic diversity index. Genetic diversity index was influenced by sample size as we concluded, and we deduced that in genetic diversity analysis, a minimum of 50–60 accessions (9.0%–10.8% percent of total accessions) was required to represent most of genetic variation, so that it could explain the total genetic variation. An adjustment of the formula for Shannon index was also proposed after a set of analyses based on accessions from Hunan and Hubei. And with it, accessions from Hubei showed higher genetic diversity than those from Hunan province.

Key words: Soybean, Genetic diversity, SSR Markers, Shannon index, He, Number of alleles, Sample size