Detection and Manipulation of Resistance to Septoria nodorum in Wheat

Abstract

A method is described for obtaining resistance to S. nodorum in wheat [Triticum aestivum]. Seedling plants in each self-fertilized, but segregating, generation (F2, F3, F4, F5) were subjected to a heavy inoculation with a mixture of isolates of S. nodorum. The most resistant plants as measured by the degree of chlorosis and necrosis, and the number and size of lesions in seedling leaves from each generation, were grown to maturity and bulk-harvested to provide seed for the next generation. The F6 progeny of all crosses were more resistant than their parents. The F7 progeny were significantly better than the F2 generation and in most cases, significantly better than their parents on the basis of number of lesions and percentage necrosis per square centimeter. The method was effective for detecting and accumulating resistance to S. nodorum in wheat seedlings.