Variability and covariability for plant height,heading date,and seed weight in wheat crosses

Summary Variability, covariability, heritability, and expected genetic gains from selection for heading date, plant height, and kernel weight were estimated in progenies derived from six wheat crosses. The crosses differed in the magnitude of the genetic variabilities of their progenies, but all crosses had significant variabilities for all traits. Heritability estimates were calculated by the variance components method. The estimates of heritability were relatively high for all three traits and averaged 86% for heading date, 77% for plant height, and 70% for kernel weight. The presence of significant genetic variabilities and high heritability estimates indicated that selection would be effective for the three traits.The segregates derived from crosses between medium tall parents showed transgressive segregation that would permit isolation of short-statured types. Transgressive segregation also occurred for heading date and kernel weight.Heading date and plant height were positively and highly significantly correlated in four crosses out of six. But both plant height and heading date had, in general, low negative correlations with kernel weight which would not preclude the development of short wheats with high kernel weight from these crosses. The association between characters was mostly genetic in cause.