Estimation of genetic variance in reciprocal recurrent selection corn composites

Abstract

This study was undertaken to evaluate the genetic variance and the genetic behavior of each of twelve corn composites developed in a reciprocal recurrent selection program. The seed sources used for this study were obtained from the reciprocal recurrent selection program conducted by the Texas Agricultural Experiment Station. Corn composites were available from six cycles of testing of the reciprocal recurrent selection study and were derived from two open-pollinated varieties: Ferguson's Yellow Dent (FYD) and Yellow Surcropper (YS). Eight single cross hybrids, with the most divergent genetic background, were used as checks of the environmental variances and were selected for their wide range of agronomic characteristics. Variation was measured by determining, first, the phenotypic values for eight plant and ear characters: silking date, plant height, ear height, ear length, ear diameter, number of rows, shelled grain and prolificacy. Then, by further partitioning of the variances associated with the composite populations, estimates of the genetic variance were computed. ...