Studies on the nature and mechanisms of resistance to rust diseases in peas

Abstract

The nature of rust resistance and its interrelationship with other economic characters were studied. Parental F1 and F2 and two back cross generations of thirteen crosses were used for the study. Chi-square method for testing the segregation ratio, generations mean method to study gene action, contingency Chi-square for association of characters were adopted. Phenols and sugars were estimated to ascertain the biochemical basis of resistance. Resistance to rust was found to be governed by a single pair of dominant genes. Plant height, pods per plant, pod weight, 100 seed weight were the important economic characters which had positive association with resistance. No linkage was found between resistance and qualitative characters like flower colour, stipule base colour, seed colour and seed shape. Dominant gene action and epistasis was observed majority of characters. However, addictiveness was also found for flowering, 100 seed weight, pod length and pods per plant. High phenols and low sugar content appeared to be responsible for resistance.