Adult plant resistance to leaf rust in 37 Indian wheats.

摘要

Analysis of 37 bread wheats for seedling and adult plant resistance with 3 pathotypes of leaf rust 77-1 (109R64), 77-2 (109R31-1) and 104B (29R23), conducted during crop year 1992-1995, enabled categorisation of wheat genotypes into 5 groups. Isogenicwheat lines showed two kinds f responses to leaf rust at 20-28 deg C in single pathotype isolated nurseries. Genes Lr13, Lr22a, Lr23 and Lr30 when present alone, restricted AUDPC between 256-413, while wheat lines carrying Lr14a and Lr34 reduced AUDPC to 733-743. In isolated nurseries with above pathotypes, Lr13, Lr23 and Lr34 when present alone or in combination with other genes in different genotypes, exhibited large variations in disease expression (AUDPC 10-953). Low to very low disease expression(AUDPC > 50) could be obtained by the interaction of 3 or more APR factors. Studies also revealed the operation of many APR factors in Indian wheat cultivars.