Genetic analyses of adult-plant resistance in five cultivars of wheat (Triticum aestivum) to leaf rust (Puccinia triticina)

Comparison of infection types produced by seedling test on 5 cultivars ('HS 240', 'PBW 343', 'HD 2687', 'UP 2425' and 'Raj 3765') of wheat (Triti' im aestivum L. emend. Fiori & Paol.) with differentials (single gene lines) against 11 pathotypes of leaf rust (Puccinia triticina Erikss.) led to the postulation of presence of leaf-rust resistance gene Lr26 in cultivars 'HS 240', 'PBW 343', 'HD 2687', JP 2425' and Lrl3 in 'Raj 3765'. Genetic analysis for adult-plant resistance in these 5 cultivars was carried out with 3 pathotypes (77-2, 77-5 and 104-2) of Puccinia triticina during 2000-2003, indicating the presence of an adult-plant resistance gene in 'HS 240', 'PBW 343', 'HD 2687', 'UP 2425' and 2 adult-plant resistance genes in 'Raj 3765'. Test ofallelism with near-isogenic line Tc 6 + Lr34 showed the presence ofLr34 in cultivars 'HS 240', 'PBW 343' and 'Raj 3765'. Analysis of F 2 crosses among resistant cultivars indicated the presence of an unidentified gene tentatively named as APR' in 'HD 2687', 'UP 2425' and 'Raj 3765'.