Mapping of leaf rust and stripe rust resistance QTLs in bread wheat x synthetic RIL population under Indian field conditions

Leaf rust caused by Puccinia triticina and stripe rust caused by Puccinia striiformis are the major wheat diseases affecting wheat production worldwide. Breakdown of race specific or major rust resistance genes by the ever evolving pathogens has emphasized the importance of race non specific or adult plant resistance genes evident from wide spread use of durable rust resistance gene complexes such as Lr34-Yr18 and Lr46-Yr29. A RIL population from Wheat X synthetic cross has been found to segregate for a number of such leaf rust and stripe rust resistance genes. The present investigation was undertaken to detect novel putative leaf rust and stripe rust QTLs effective against Indian isolates. A total six leaf rust and five stripe rust QTLs could be detected using composite interval mapping based on screening of wheat X synthetic RIL population for three crop seasons.Two major gene complexes were detected, one each on chromosome 7DS and 3BS, corresponding to Lr34-Yr18-Yr18’ and Lr27-QYrr-3B were found to be effective against Indian leaf and stripe rust isolates. All the other stripe rust QTLs mapped in previous studies were also found to be effective under Indian field conditions as well. Four minor putative novel leaf rust QTLs were detected, two of which were contributed by the synthetic parent. All the QTLs found to be effective during the present investigation can be exploited for wheat germplasm enhancement using marker assisted selection.