Inheritance and Allelism of Resistance to Soybean Mosaic Virus In Corsica.

Soybean mosaic virus (SMV) is an important soybean disease and causes a drastic reduction of soybean seed yield and quality. The soybean cultivar Corsica (PI559931), developed in Maryland, has exhibited a different pattern of response to SMV strains than other reported resistant varieties. The hypothesis of this study is that Corsica may contain a new gene or allele for SMV resistance. The objectives of this research are to understand the inheritance of SMV resistance in Corsica and to evaluate the genetic relationship between the gene(s) in Corsica and other named genes.  To study the inheritance of the resistance gene(s), Corsica was crossed with Essex, a susceptible cultivar, and the progeny were inoculated with SMV strain G7.  Corsica was also crossed with PI96983 (Rsv1), L29 (Rsv3), and V94-5152 (Rsv4), and were inoculated with SMV strain G7 to study the allelic relationships of genes present in these populations.  The results confirmed the monogenic SMV resistance in Corsica, and the resistance gene is located at the Rsv1 locus. Molecular research is on-going to verify this new allele.