Evaluation of Ethiopian Durum Wheat Varieties and Landrace Cultivars for the Adult Plant Resistance of Wheat Leaf Rust (Puccinia triticina)

Abstract

Wheat Leaf rust caused by the pathogen Puccinia triticina is a serious threat of wheat production in Ethiopia, yield loss due to
this disease reached up to 70%. A study was carried out to identify leaf rust adult plant resistance in commercial durum wheat
cultivars and landraces. 35 durum wheat Varieties and 200 durum wheat landraces with three susceptible checks arranged in
Augment design and evaluated against leaf rust at Debere Zeit Agricultural Research Center, Ethiopia during the 2017/18 main
season. Terminal Rust Severity (TRS), Coefficient of Infection (CI), Area under Disease Progress Curve (AUDPC) and Disease Progress Rate (DPR) were used to measure leaf rust adult plant resistance in the test materials. Analysis of all disease parameters was carried out using SPAD software. There were highly significant differences (P<0.01) for all disease parameters among the test cultivars. Above half of evaluated Varieties and landraces (57.9 %) showed better Adult plant resistance under high disease pressure. From the total of 235 tested Varieties and landraces, 136 had slow rusting resistance of which 14 were released varieties and the rest 122 were landraces. Four commercial Varieties (Selam, Mossobo, Bekelcha, and Utuba) and a landrace cultivar (Mcd4-32) had high levels of field resistance with very low AUDPC, ACI, and TRS with MR infection type; hence, they may carry major resistance gene (s). However, the rest 99 Varieties and landraces exhibited high to moderate level of slow rusting resistance with MS responses and may have adult plant resistance controlled by minor resistance genes. The slow rusting cultivars identified from the current study can be used for further manipulation in wheat improvement programs.