EVALUATION OF ETHIOPIAN DURUM WHEATS FOR RESISTANCE TO LEAF RUST IN MEXICO

Abstract

Leaf rust, caused by the fungus Puccinia triticina E., continues to be one of the most important diseases of durum wheat in Mexico and the world. One of the most efficient ways to control the disease is through genetic resistance, which implies the need to identify sources of resistance, either in cultivated varieties, in species related to the genus Triticum, or in landrace genotypes from centers of origin or diversity. The objective of this study was to evaluate phenotypically in the field and greenhouse wheats native to Ethiopia. Of 194 genotypes evaluated against the races of P. triticina BBG/BPCG and BBG/BPCJ, 89 genotypes were identified as resistant against the BBG/BPCG race, equivalent to 45 %, and 91 against the BBG/BPCJ race, representing 46 %. Thirty-one percent of the genotypes remained resistant with the same degree of severity for both races, but 15 % of genotypes increased their level of resistance when evaluated with the BBG/BPCJ race in relation to BBG/BPCG, whereas for 50 % of genotypes the severity of the disease increased. It is important that future tests to identify sources of resistance, as well as the follow-up of the incorporation of those already identified are performed with the BBG/BPCJ race, which is the most prevalent since its appearance in Mexico in 2017. The study allowed to identify resistant genotypes at all stages of development, as well as genotypes with effective resistance only in the adult plant. Of the genotypes evaluated, 98 landraces and five improved varieties were selected as resistant. These individuals could be used as sources of resistance in breeding programs to incorporate resistance to leaf rust.