GENETICS OF RESISTANCE TO STEM RUST IN ADULT PLANT OF ELITE GENOTYPES OF BREAD WHEAT

Abstract

Wheat (Triticum aestivum L.) rusts caused by fungi of the genus Puccinia are diseases of global importance. The most effective strategy to control these fungi is plant breeding. Currently, some genotypes have shown resistance levels against these diseases. This research determined the genetics of stem rust (Puccinia graminis f. sp. tritici) resistance in bread wheat genotypes Huites M95 and LC-150 through analysis of F3 progeny derived from crosses between Cacuke, Bonza 63, Romero 73, Apav-14 and Apav-92. Segregation of F₃ families indicated that Huites M95 has two resistance genes with additive effects: Sr58 and an unnamed gene; Apav-14, Cacuke, Romero and Bonza 63 carry a single gene. The LC-150 parent carries two additive genes, Sr58 as in Huites and an additional one. F3 progeny analysis confirmed the presence of three genes with additive effect in crosses LC-150 by Cacuke and Bonza 63. The slow rusting adult plant resistance gene Sr57 was detected in the Romero and Cacuke genotypes. Sr2 was detected in Cacuke and Apav-14, and Sr58 in Huites M95, Romero 73, Cacuke, LC-150, Apav -14 and Bonza 63. This is the first report in Mexico of Huites M95 and LC-150 as a source of adult plant resistance to wheat stem rust, which can be used as progenitors in breeding programs to achieve durable resistance.