Comparative analysis of soybean (glycine max) accessions using inter simple sequence repeat (ISSR) and random amplified polymorphic DNA (RAPD) markers

Abstract

Soybean (Glycine max) is an important crop in the world in terms of total production and usage. It is also among the least diverse species. The main objectives of the present study were 1) to determine differences between ISSR and RAPD marker systems in detecting genetic variation in soybeans and 2) to identify and characterize accession- diagnostic molecular markers in G. max accessions. Genomic DNAs from 108 G. max accessions from 11 different gene pools were analyzed using several ISSR and RAPD primers. The levels of polymorphic loci detected with the two marker systems were in general moderate and similar.. Overall, 82% of genetic distance values were above 0.40 based on ISSR analysis. However, RAPD data revealed that the accessions from different countries are closely related with 64% genetic distance values below 0.40. The dendrograms constructed with ISSR data revealed that the South Korean accessions formed an out-group while the RAPD analysis showed that accessions from Sweden were separate from the other 10 gene pools. One variety-diagnostic marker generated with ISSR 5 primer was identified in the accession Kao Chien Tao from China. This marker was cloned, and sequenced. Although RAPD and ISSR marker systems detected similar levels of genetic variability, they target different regions of the soybean genome, resulting in different clustering of the 11 gene pools indicating different genetic relatedness among them. This finding demonstrates the usefulness of both marker systems in assessing diversity and relatedness among Glycine max gene pools.