Genetic confirmation of 2 independent genes for resistance to soybean mosaic virus in J05 soybean using SSR markers.

J05 soybean was previously identified to carry 2 independent genes, Rsv1 and Rsv3, for "soybean mosaic virus" (SMV) resistance by inheritance and allelism studies. The objective of this research was to confirm the 2 genes in J05 using molecular markers so that a marker-assisted selection can be implemented. The segregation of F(2) plants from J05 x Essex exhibited a good fit to a 3:1 ratio when inoculated with SMV G1. Three simple sequence repeat (SSR) markers near Rsv1, Satt114, Satt510, and Sat_154, amplified polymorphic DNA fragments between J05 and Essex and were closely linked to the gene on soybean molecular linkage group (MLG) F, thus verifying the presence of Rsv1 in J05 for resistance to SMV G1. The presence of Rsv3 in J05 was confirmed by 2 closely linked SSR markers on MLG B2, Satt726 and Sat_424, in F(2:3) lines that were derived from the SMV G1-susceptible F(2) plants and segregated in a 1:2:1 ratio for reaction to SMV G7. Two closely linked markers for Rsv4, Satt296 and Satt542, segregated independently of SMV resistance, indicating the absence of Rsv4 in J05. These SSR markers for Rsv1 and Rsv3 can serve as a useful molecular tool for selection and pyramiding of genes in J05 for SMV resistance.