Genetic studies in wheat for leaf rust resistance (Puccinia recondita)

Leaf rust is a major disease of wheat crop in the world as a whole. This study was undertaken to find the genetic effects of adult plant leaf resistance in wheat (Triticum aestivum L.). Three wheat crosses were developed from three resistant and one susceptible parent. Six populations (P(1), P(2), F(1), F(2), BC(1) and BC(2)) of each cross were grown under field conditions and were artificially inoculated with isolates of mixture of leaf rust prevalent races. Leaf rust intensity and reaction type were observed and the coefficient of infection was computed. Generation means and variance analyses were performed for the estimation of additive, dominance and epistatic genetic effects. Additive and dominance, as well as epistatic genetic effects, are involved in the inheritance of leaf rust resistance. However, the narrow sense heritability estimates were low, which also exhibited the presence of epistatic genetic effects. Thus, selection of resistant adult plant in later segregating generations would be useful for the development of high yielding wheat genotypes.