Triple testcross analysis of F2 and irradiated F2-derived lines of Pisum sativum L.

Abstract

The triple testcross breeding design was applied to a set of F7 and RF7 pure-breeding lines derived from normal and irradiated F2 seeds of the cross 'Bonneville' × T 163. Two phenotypically extreme lines and their F1 were used as testers in both control and irradiated materials. Epistasis was, in general, not an important component of variation. Additive component was the most important, while dominance was detected in 3 of 10 cases. The additive and dominance components in general decreased following irradiation as a result of additive and dominance effects of induced new alleles being smaller than those generated by the original alleles they replaced.Key words: triple testcross, irradiation, single seed descent, genetic anaylsis, pea.