Quantitative studies on heterosis and inbreeding depression in quality protein maize for terminal heat tolerance

Abstract

The present investigation was carried out for studying heterosis and inbreeding depression of twenty eight hybrids (F1ʼs) and their F2ʼs made by crossing of eight Quality Protein Maize inbreds in all possible cross combinations excluding reciprocals. Five cross combinations were found to be heat tolerant as they didn’t show any symptoms of leaf firing, tassel blast, root lodging and no severe loss of yield in the present investigation. Variable magnitude of heterosis was observed for different cross combinations for all the traits. Based on higher mean performance for grain yield per plant (30.53 to 40.47 g/plant) and higher heterotic response (0.74% to 18.24%), sixteen crosses were selected. Response of inbreeding depression was significant in positive direction for most of the traits. Among these sixteen crosses, eight crosses were selected having high heterotic value (3.46 to 18.24%) and lower inbreeding depression (< 15%) and may be further utilized for the development of superior hybrids after confirming their consistency in Allahabad agro-climatic conditions.