Genetic variability in the segregating generations and the breeding strategies for selection to improve yield and resistance to rust in pea

A rust susceptible genotype of pea HUVP 1 was crossed with a rust resistant genotype FC 1. One hundred F₄ and F₅ single plant progenies were grown along with parents and the infector rows. In both the generations, a wide range of variation was observed for plant height, pods per plant, 100-seed weight, yield per plant and AUDPC, indicating considerable scope for selection. Narrow sense heritability was estimated by regression of F, progenies on the F₄ parents, both F₄ and F₅ were evaluated in the same season to avoid environmental and season x generation interaction effects. High heritability accompanied with high estimates for genetic advance were observed for AUDPC, yield per plant and pods per plant. The estimated number of gene(s) in the segregating generations varied from 1.3 for 100-seed weight to 7.3 for seed yield per plant in the F₅. Positive and highly significant correlation was obtained between pods per plant and yield per plant and between AUDPC and pustule size in both the generations. Path-coefficients analysis showed that pods per plant and seeds per pod had high direct positive effect, whereas 100- seed weight had moderate positive direct effect on yield in both the F₄ and F₅ generations.