A Simple method for determining barley reaction to spot blotch disease

Abstract

A simple method was used to determine the reaction of 14 barley genotypes to Cochliobolus sativus, the causal agent of barley spot blotch disease. In this assay, fivetransparent centered circles ranged from resistant to very susceptible, was used to screenbarley genotypes for resistance to the major virulent pathotype Pt4 in barley populationsin Syria. The center of circles placed on the started point of lesion and its extendedthrough the circle could give numerical values for each genotype. The method allows low,intermediate and absolute levels of resistance to spot blotch to be determined. Thetransparent circles method was repeatable and the disease scores obtained were correlated(r = 0.97, P < 0.001) with those obtained by the seedling assay. The established method isboth simple and precisely, it could make a significant contribution in many types ofstudies in plant pathology breeding programs.