Special Issue Article
Abiyot Lemma, Getaneh Woldeab
Abstract
Wheat stem rust caused by Puccinia graminis f.sp. tritici is amongst the biotic factors which causes up to 100% yield loss during epidemic years. Ethiopia is considered as a hot spot area for the development of stem rust complex; and hence, this study was carried out to investigate the distribution and intensity of wheat stem rust, and to detect the virulence spectrum of P. graminis f.sp. tritici. The survey result showed that 30 (38.9%) of the fields were affected with stem rust. The overall incidence of the disease was 5.2% and the mean severity of the disease was below 5%. The lowest incidences and severity were noted at Gimbichu while the highest were at Adeaa District. P. graminis f. sp. tritici variability study was resulted in the identification of 16 races of which race SRKSF was the most prevalent with a frequency of 14.3% followed by the races such as TTKSK and TTTTF with frequencies of 7.1% and 3.6%, respectively. Differential host carrying Sr24 was effective to all races considered, while gene Sr36 gene was resistant to 85.7% of the races. These two genes could be used in resistance breeding program of wheat.