VIRULENCE CHARACTERIZATION OF LEAF RUST ISOLATES FROM 2017-18 WHEAT CROP OF SINDH PAKISTAN

Abstract

Wheat leaf rust disease, caused by Puccinia triticina poses severe threat to the 80% of the wheat cultivated across Pakistan. One hundred and twenty-nine leaf rust samples collected from Sindh during 2017-18 wheat cropping season were processed and eleven single uredinial isolates were revived and analyzed using North American set of differentials. Seven virulent profiles were found amongst these isolates. LKTSS was most common, found in four isolates; LKFJS was identified in two isolates. MKPSS, LKFKS, PKKSS and LKHSS were identified in single isolate only. Virulence was absent for Lr2a, Lr9, Lr19, Lr27+31 and Lr28. Whereas only a single isolate PKKSS was virulent to Lr2c and isolate LKFKS to Lr18. Virulence for the leaf rust genes Lr1, Lr16, Lr24, Lr28, Lr17, Lr30, Lr10, Lr14a, Lr3bg, Lr14b, Lr20, Lr13, Lr23, Lr22b were found along with Morocco under controlled condition. Overall high frequency of leaf rust phenotypes were identified in limited number of samples. The avirulence/virulence information of Lr genes should be utilized in gene deployment and breeding programs, particularly for Sindh province.