Genetic Properties of Inhibitor Genes in Flax Rust that Alter Avirulence to Virulence on Flax

Abstract

The properties of inhibitor genes in two strains of flax rust (Melampsora lini) that alter avirulence to virulence on flax (Linum usitatissimum) were investigated by testcross analysis. In rust CH5, and single gene or a tightly linked cluster of genes, designated 1-1, was shown to inhibit interactions involving the A-L1, A-L7, A-L8, A-L10, and A-M1 avirulence genes. In rust I, a second inhibitor gene, designated, 1-2, inhibited interactions invoving the A-M1 gene and was shown to be allelic or very tightly linked to I-1. It is suggested tat I-1 may have two components, one of which is L group specific and the other M group specific, while I-2 has only one of these.