Assessment of Genetic Variation in Soybean (<i>Glycine max</i>) Accessions from International Gene Pools Using RAPD Markers: Comparison with the ISSR System

Soybean (Glycine max) is one of the most important crops 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 to 1) assess the level of genetic variation among soybean (G. max) accessions from different countries using Random Amplified Polymorphic DNA (RAPD) markers and 2) compare Inter Simple Sequence Repeats (ISSR) and RAPD marker systems in detecting polymorphic loci in soybeans (G. max). Genomic DNAs from 108 soybeans (G. max) accessions from 11 different gene pools were analyzed using several ISSR and RAPD primers. The average level of polymorphic loci detected with the RAPD primers was 35%. The soybean accessions from the China, Netherlands, and Canada gene pools were the least genetically variable with 25%, 26%, and 30% of polymorphic loci, respectively. Accessions from Hungary (43%) and France (48%) showed the highest level of polymorphism based on the RAPD analysis. Overall, RAPD data revealed that the accessions from different countries are closely related with 64% genetic distance values below 0.40. The levels of polymorphic loci detected with the RAPD and ISSR marker systems were in general moderate and similar even if they target different regions of the genome. A combination of different marker systems that include RAPD/ISSR, microsatellites (SSR), and SNPs should provide the most accurate information on genetic variation of soybean (G. max) accessions.