Diallel Analysis of Duration and Rate of Grain Filling of Seven Inbred Lines of Corn1

Abstract

A diallel cross of seven inbred lines of corn (Zea mays L.) was examined for duration of the grain‐filling period, rate of fill, and associated agronomi characters to determine the practicability of selection for these traits. The length of the grain‐filling period and the rate of grain filling differed among hybrids and between years, but interactions between years and hybrids were not detected. Hybrids did not differ for duration of the lag phase of the grain‐filling period.The general combining ability effects for duration and rate of grain filling were larger than specific combining ability effects which snggested that simple selection techniques should be effective in changing these characters within the material studied. A phenotypic correlation of 0.81 was found between duration of the grain‐filling period and grain yield, while the correlation between rate of fill and grain yield was nonsignificant.Although the association between duration of the filling period and ear moisture content at harvest was high (r = 0.82), there was some evidence that it might be possible to shorten the vegetative period without sacrificing yield.