Estimation of gene effects for powdery mildew resistance in garden pea (Pisum sativum)

Abstract

Generation means analysis was carried out to estimate the nature and magnitude of gene action for identifying the
segregants resistance to powdery mildew disease of garden pea (Pisum sativum L.). Six generations (P₁, P₂, F₁, F₂, B₁ and B₂) of three crosses, VRP 16 × VRP 22, VRP 16 × VRPMR 9 and VRP 343 × Arka Ajeet were grown for evaluation of disease incidence (DI), per cent disease index (PDI) and area under disease progress curve (AUDPC). AUDPC values revealed differential rate of disease development on various genotypes of pea. Highest rate of disease development was observed on VRP 16 (667.00) and lowest on VRP 22 (74.09). Both additive and dominance gene actions were found to be important in inheritance of powdery mildew resistance (all the three characters) including non-allelic interactions. In view of the parallel role of additive and non-additive gene effects, selection in the segregating generations should be delayed to diminish the dominance gene effects. Duplicate type of epistasis was detected for all the three pathological characters in all the crosses whose effect can be eliminated by following sophisticated selection procedure such as reciprocal recurrent selection and/or biparental mating in early segregating generations for the development of powdery mildew resistant varieties.