G x E interaction studies in relation to heterosis and stability of grain yield in maize (Zea mays L.)

Interaction of homozygous inbreds and heterozygous single, three way and double crosses with environment had shown a differential response in achieving yield stability. Seven diverse maize inbreds, their 21 single crosses and 105 each of three way and double crosses obtained through diallel were evaluated for twelve characters across three diverse locations to estimate comparative stability of homozygous and heterozygous genotypes for grain yield. Contrasts in heterobeltiosis, combining ability and stability parameters in three environments and interaction effects were observed. Gain in heterobeltiosis (%) for grain yield o was observed with decreased environmental quality in different hybrid classes suggesting that heterozygous hybrids are more stable due to individual buffering in single crosses and both individual and population buffering in case of three way and double crosses. Significant increase in SCA effects was observed in moderate environment at Hyderabad rather than at high yielding environment Palem. Significant G x E and Environment (linear) in all the crosses was observed for grain yield suggesting the effect of environment and its pre dominant effect on grain yield. Stability of hybrids was attributed to their superior performance over the parents in low yielding environment. Thus the potential use of selected heterozygous hybrids would allow under diverse environments is suggested to mitigate losses arising out of climate change.