Genetic relatedness of soybean genotypes based on agromorphological traits and RAPD markers

Abstract

Modern agriculture, breeding procedures, as well as competition among breeding institutions contribute to further reduction of already narrowed diversity of soybean commercial varieties. The objective of the study was to characterize eighteen soybean cultivars from three different breeding programs for agro-morphological traits and to reveal genetic diversity using molecular markers. Morphological description was performed with 13 qualitative and 9 quantitative traits. The genetic relationships were estimated using 21 RAPD markers. PIC was calculated for RAPD data, while the diversity of qualitative traits was described by Shannon genetic diversity index. Cluster analysis based on qualitative morphological characters showed clear separation of genotypes on the basis of their plant growth type. PC analysis performed for quantitative traits divided genotypes according to their maturity group. Grouping pattern based on molecular marker data was in agreement with pedigree of cultivars. A great similarity was found, primarily between the varieties under the same institution, and then among all examined varieties. Comparison of three methods in the assessment of diversity indicated that morphological markers might provide useful information in breeding process and allow classification by pedigree to some extent, but RAPD markers were found to be superior in assessing differences among genetically very similar genotypes.