Response of wheat cultivars to infection by Stagonospora nodorum isolates/mixture on detached and intact seedling leaves

Stagonospora nodorum blotch (SNB) of wheat caused by Stagonospora nodorum ( Berk.) Castellani & E.G. Germano is among the major foliar diseases of whea t worldwide. The response of four wheat cultivars for reaction to infection by isolates/mixture of S. nodorum was tested on detached and intact seedli ng leaves in the laboratory and glasshouse experiments, respectively. The f our wheat cultivars tested significantly differed from each other in respon se to infection by the isolates/mixture of S. nodorum. Similarly, the aggre ssiveness of the four isolates/mixture of the pathogen on the four wheat cu ltivars was significantly different as demonstrated by the parameters teste d in the two experiments. However, no significant (p less than or equal to 0.05) isolate x cultivar interaction was observed for all the parameters te sted in the two experiments. Highly significant positive or negative correl ations were observed between parameters, i.e., disease severity (DS), incub ation period (IP), and size of necrotic lesions (SNL), tested on detached a nd intact seedling leaves, respectively. This suggests that use of the deta ched leaf technique has considerable promise for quick screening of wheat c ultivars against SNB.