Tigray Agricultural Research Institute (TARI), Mekelle Agricultural Research Center P.O. Box 258, Mekelle, Ethiopia.
Wheat Leaf rust (Puccinia triticina Eriks and Henn.) is one of the most important foliar diseases of wheat in Tigray region. It cause up to 75% yield loss during epidemic years. Hence, this study was conducted to determine the distribution, intensity and to detect the virulence diversity of the pathogen in Eastern and Southeastern zones of Tigray. The findings of this paper were based on leaf rust surveys to compute the prevalence and intensity of the diseases; race analysis by inoculating isolates on to the 16 differential hosts. During the survey, 108 wheat fields were assessed in five districts, of which 88% of the fields were affected with leaf rust. The overall mean incidence and severity of the disease were 48.4 and 18.2%, respectively. A total of 22 races were identified from 40 isolates, of which PHTT, PHRT, THTT and FHRT were predominant races with frequencies of 20, 15, 10 and 10% respectively. The remaining 18 races were confined to specific locations and detected once with a frequency of 2.5% each. The broadest virulence spectrum was recorded from TKTT race, making 15 Lr gens ineffective. Most of the Lr genes were ineffective to one or more of the tested isolates except Lr9. High virulence was observed on Lr3, Lr10, LrB and Lr18 with frequencies of 90, 95, 97.5 and 100%, in that order. In contrast, Lr9, Lr24 and Lr2a were found effective to 100%, 95% and 82.5% of the tested isolates, respectively. Hence, the use of Lr9, Lr24 and Lr2a genes singly or in combination through gene pyramiding has paramount importance as the additive effects of several genes offer the variety a wider base for leaf rust resistance along with periodic race survey to track further virulence evolution.
Tesfay Gebrekirstos Gebremariam(2018) Prevalence and physiologic races of wheat leaf rust in Tigray, Ethiopia, Int. J. of. Life Sciences, Volume 6(2): 301-310.
All the authors are very thankful to Principal, Janata Mahavidyalaya, Chandrapur for providing the full research facilities to conduct the present work.
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