Phenotypic and molecular diversity among soybean cultivars as a function of growing season

Abstract

The identification of divergence among cultivars adapted to specific soil and climatic conditions is of fundamental importance for the realization of promising hybridizations. This diversity can be accessed through phenotypic characteristics and molecular markers. In this sense, the objective of this study was to evaluate genetic diversity of soybean cultivars in the summer and winter from agromorphological traits and molecular markers. Two experiments were conducted, one in the summer (2011) and another in the winter (2012). The experiments were conducted in a randomized block design with four replications. Six widely grown cultivars were used and they showed striking differences in regards to morphological markers. The cultivars are: M 7211 RR, TMG 123 RR, TMG 1176 RR, M 7908 RR, TMG 127 RR and TMG 7188 RR. During the development of the plant, as well after harvesting were evaluated 18 traits. The DNA of six cultivars was amplified with 16 primers (microsatellite markers) flanking microsatellite regions in soybean located in sixteen of the twenty soybean linkage groups. Genetic dissimilarity between cultivars from agromorphological traits varies depending on the growing season. The molecular markers showed genetic variability between cultivars with different results for clusters formed from the agronomic characters. Thus, both phenotypic and the molecular data proved to beinformative tools to characterize the existing conflict between soybean cultivars.