Evaluation of Soybean [Glycine max (L.) Merrill] Germplasm for Field Weathering Resistance using Seed Quality and SCAR Markers

Abstract

Forty-eight soybean varieties/lines along with resistance and susceptibility checks were grown at the National Corn and Sorghum Research Center, Nakhon Ratchasima province, Thailand in a randomized complete block design with three replications. At physiological maturity, soybean pods were harvested and subjected to incubator weathering, controlled deterioration and electrical conductivity tests to evaluate the seed quality. Soybean seed physical characteristics, including seed coat percentage, seed weight and seed coat color were also investigated. Two sequence characterized amplified region (SCAR) primers, Eaag/Mcac-233 and Eact/Mctt-157, previously reported to link with a quantitative trait locus (QTL) that controlled field weathering resistance, were used to amplify the DNA of the 50 soybean varieties/lines. The results revealed that 48 soybean varieties/lines were significantly different in seed quality and seed physical characteristics. They were classified into four groups: resistant, moderately resistant, moderately susceptible and susceptible to field weathering, according to the average germination percentage after incubator weathering and controlled deterioration. The overall field weathering resistance was found to correlate with seed quality and seed physical characteristics. The two highest correlation coefficients were found between field weathering resistance and germination percentage after incubator weathering (r = 0.898**) and controlled deterioration (r = 0.888**). The two SCAR primers were able to differentiate between resistance and susceptibility checks but were unable to classify field weathering resistance in 48 soybean varieties/lines. It was concluded that the two markers were not appropriate for evaluating field weathering resistance in the soybean varieties/lines.