Identification and distinction of soybean commercial cultivars using morphological and microsatellite markers

To identify and discriminate 15 soybean commercial cultivars, 11 morphological characteristics viz. plant height, timing of beginning of flowering, timing of maturity, anthocyanin of hypocotyl, growth type, color of hairs on main stem, shape of lateral leaflets, flower color, intensity of brown color of pod, seed coat color due to peroxidase activity, and seed hilum color were assessed and measured. This experiment was conducted during 2007-08 growing seasons using randomized complete block design with three replications in Karaj. Distinctness of cultivars was determined using UPOV’s recommended method for two growing seasons (COYD). Considering seed hilum color, color of hairs on main stem, and flower color soybean cultivars were grouped in similar group. Pair-wise tables were used for discriminating within-group cultivars by other qualitative traits. Analysis of variance for quantitative traits showed very high significant differences (p<0.001) between cultivars. Molecular tests, 16 microsatellite markers were used in cultivars fingerprinting. These markers could distinguish between cultivars except two of them. To determine optimum combination of markers, all markers were used which led to selection of three SSR loci; Satt231, Satt005, and Satt274. These three microsatellite loci with the most discriminative power and effective number of alleles were used in cluster analysis and led to the same distinction results using 16 markers. Since these markers are not influenced by environmental conditions, therefore, could be utilized as complementary traits to morphological and physiological characteristics in identification of soybean cultivars.