Research Article
Pallavi JK, Anupam Singh, U
Abstract
The goat grass (Aegilops speltoides) derived seedling leaf rust resistance gene Lr28 is effective in providing resistance against infection to leaf rust including its most virulent strain, 77-5 (121R63-1) of the pathogen. A polymorphic SSR marker specific to Lr28 was identified by employing bulk segregant analysis on an F2 population derived from the cross between PBW343-Lr28, a leaf rust resistant near isogenic line of the most cultivated variety PBW343 and CSP44-Lr48, the Australian cultivar Condor derived CSP44 line carrying the APR gene Lr48. The marker amplified a polymorphic fragment which was particular to the presence of the seedling resistance gene and it was mapped at a distance of 2.9 cM from the Lr28 resistance locus on chromosome 4AL. It was also validated on a set of 42 NILs which carried other potent leaf rust resistance genes of diverse origin. Such a polymorphic codominant SSR marker will be useful in wheat breeding programmes to differentiate plants homozygous at the Lr28 locus from those that are heterozygous.