Estimation of general combining ability effects on phenological, physiological and yield component under non-stress and stress conditions in maize

Abstract

Maize is one of the most important crops of world agricultural economy and ranks third next to rice and wheat in production. By origin, maize is native to South America and has adapted significantly to temperate condition with much higher productivity. Performance of inbred lines in top crosses with divergent half Diallyl crosses known origin can be used as a practical tool to determine the heterotic patterns among the lines under drought and non-stressed conditions. Ten corn inbred lines (DMIL 230, DMIL 438, DMIL 447, DMIL 516, DMIL 553, DMIL 607, DMIL 692, DMIL 715, CML 425 and NC 468) were used as female and male parents. GCA is the relative ability of an individual to transmit genetic superiority to its offspring when crossed with other individuals, although the GCA of a parent signifies the average performance of its progenies in various crosses, compared with progenies of other parents in the same test and the breeding value of a parent is twice its GCA, while SCA is the degree to which the average performance of a specific family (usually full sibs) departs from the average of its parental breeding values. DMIL 447 (-0.86), DMIL 516 (-0.62) under stress recorded significant negative gca effects indicating that they were good combiners for days to 50 per cent anthesis. The DMIL 553 (22.18) and NC 468 (26.65) parents were recorded significant positive gca effects under stress for good combining ability CML 425 (0.01) recorded non-significant positive gca effects proved to be a good combiner for DSI.