Abstract only

The CIMMYT global wheat improvement program is committed to characterizing and utilizing slow-rusting, adult plant resistance (APR) to all three wheat rusts, including the Pgt race Ug99 group, to achieve durable resistance. The Kenyan cv. Kenya Kudu displays high levels of APR to the Ug99 race group. We developed and phenotyped a PBW343/Kenya Kudu RIL population of 174 F6 lines for response to stem rust, leaf rust and stripe rust in field trials at Njoro, Kenya, and Ciudad Obregon, and Toluca in Mexico, respectively. After genotyping the lines with 550 DArTand 35 SSR polymorphic markers we performed Inclusive Composite Interval Mapping to identify QTL associated with the resistances. QTL for stem rust resistance were located on chromosomes 1A, 1B, 3B, 7A and 7B and accounted for a total adjusted R2 of 75%. Four (1B, 2B, 4A, and 7D) and five (1B, 2B, 3A, 4A, and 7A) chromosomal regions were associated with stripe rust and leaf rust resistances, respectively. Parents of the populations were polymorphic for markers associated with APR genes Lr46/Yr29 and Sr2/Yr30. The RIL population was scored for these markers and lines were identified with the genes singly and in combinations. Disease severities for all three rusts were reduced in the presence of Lr46/Yr29 and Sr2/Yr30 supporting previous reports that the pleiotropic Lr46/Yr29/Pm39 locus confers APR to stem rust.

Genetic Resources Program|Global Wheat Program

English

Lucia Segura

INT3098|INT0610

CIMMYT Staff Publications Collection