Assessment of Diseases on Wheat Rusts Trap Nursery in Southern Ethiopia

Abstract

The rusts diseases caused by Puccinia, species are the major biotic constraints in many wheat producing areas of Ethiopia. The present study was conducted in 2015 and 2016 main growing season to observe commercial varieties and differential lines of bread and durum wheat for their resistance to the existing race composition. About 200 wheat varieties and lines were included in trap nursery for evaluation of triple rust was investigated under natural conditions. The presence of sufficient genetic variability among the wheat entries and varieties indicated different response ranges for the extent of resistance/susceptibility to triple rusts of wheat. The peak average severities of stripe stem and leaf rust diseases on wheat entries were 45%, 85% and 60%, respectively. The differential lines also showed divers range of reaction to rusts. The maximum diseases severities of 65% and 40% were recorded on stem and yellow rust differential, respectively. Whereas the highest diseases severity of 25% was recorded from leaf rust differentials line. The wheat genotypes to leaf rust give the best performance and overlap with yellow and stem rust in some wheat lines. The trap nursery provides an important source of resistance gene to wheat rust disease. However the resistance gene of these varieties will be break through time due the involvement of new race or prevailing environmental factor. Therefore, continues releases and exploitation of new resistant varieties is an important strategy through selecting promising wheat genotype in order to improves the grain yield and quality of produce.