Field Evaluation and Molecular Validation of Soybean Genotypes for Resistance to Yellow Mosaic Disease using SSR Markers

Background: Various biotic factors adversely affect the growth and productivity of soybeans. Viruses are one of them, as they cause significant loss to the yield of soybeans in India. The present study was conducted to identify yellow mosaic virus (YMV) resistant genotypes. Methods: Field screening was performed in disease hotspot conditions to identify YMV-resistant genotypes among 70 soybean genotypes. The field data of a selected set of 40 genotypes was compared with molecular data recorded using gene-specific SSR molecular markers. Result: In a field study involving seventy soybean genotypes, eighteen were highly resistant, twenty-seven were moderately resistant, eighteen were moderately susceptible and six were susceptible to yellow mosaic diseases. Only one genotype, JS 93-05, was highly susceptible to the disease. The genetic relationships among the soybean genotypes were examined using SSR markers and fifteen primers, effectively amplified soybean genomic DNA. The polymorphic information content (PIC) scores were used to assess genetic diversity for specific loci. The PIC values ranged from 0.00 (Sct_199) to 0.84 (Satt 267), with an average of 0.43. The alleles varied from 1 to 3, with an average value of 2.1 and the allele sizes ranged from 60 to 260 base pairs. A UPGMA cluster analysis based on genetic distance data resulted in a dendrogram that grouped the soybean genotypes into two main groups, A (20) and B (20). Group A was further divided into subgroups A1 (16) and A2 (04), while Group B was divided into subgroups B1(07) and B2(13). The highest similarity (0.94) was found between RVS 13-7 and JS 20-116, while the lowest similarity (0.41) was observed between NRC 192 and RVSM 2012-4.The resistant genotypes identified in this study may be used as donors of resistance genes against YMV to develop improved genotypes, which would stand as barriers against the spread of the disease to newer areas and thus boost the production and productivity of soybeans in the country.