Adult-plant leaf rust resistance in Thatcher and Marquis wheat: a genetic analysis of the host–parasite interaction

Abstract
Inheritance of adult-plant resistance to race 9 of leaf rust was investigated in the wheat varieties Thatcher and Marquis. Resistance was conferred by the same recessive gene in both varieties. The genetics of virulence on adult plants of Thatcher was studied in a F2 population of cultures from a cross between races 9 and 161. A single recessive gene conferred virulence on adult plants of Thatcher. This gene was inherited independently of the genes that condition virulence on host genes Lr1, Lr2, Lr3, and Lr11.