Heritablity of Resistance to Cowpea Aphd (Aphis craccivora Koch) in Yard Long Bean and Cowpea.

Abstract

An experiment was conducted to investigate mean population of aphids, damaged scores, heritability and generation mean analysis of aphid resistance in yard long bean and cowpea. Six generations including P₁ , P₂ , F₁, F₂ BC₁and BC₂  from 4 crosses were evaluated in RCB under a screenhouse condition at the Faculty of Natural Resources, Prince of Songkla University, Hat Yai, Songkla province during February and Max 2007. Five adult aphids (Aphis craccivora) were released on each plant at the 3^rd week after germination.  Genetic analysis using generation means revealed significant difference among generation. Significant additive and dominant gene effects on aphid damages were observed only in one cross (Selected-PSU x IT82E-16). The epistasis interaction of additive x additive also responsed for the interaction of this trait. The highest heritability of damaged score (55.941%) was found in Selected – PSU x IT82E – 16 cross.