Interrelationships Among Yield Stability and Yield Components in Early Maize1
- H. Z. Cross2
A very early and an early set of made (Zea mays L.) hybrids were grown in nine and 11 environments, respectively, to evaluate the relationships between yield stability, as estimated by regression analysis, and various agronomic traits. Results indicated that general stability, as estimated by the regression coefficient, was associated with yield, kernel depth, and number of kernel rows per ear. Specific stability, estimated by the mean squares of deviations from regression, was associated with ears per plant. Within the later maturing diallel set, hybrids with more ears per plant had lower deviation mean squares, while the opposite was found within the earlier diallel set.
Correlations among general combining ability (GCA) effects for various traits were computed to evaluate their associations within each of the two populations. Correlations among GCA effects were in general agreement with the phenotypic correlations. Generally, inbreds with high GCA effects for kernel depth and kernel rows per ear had high GCA effects for yield. Correlations between GCA effects for kernel depth and kernel rows per ear were 0.62 and 0.64 for the late and early maturing diallels, respectively.
The absence of environmental interactions with GCA or specific combining ability (SCA) effects for kernel depth indicated selection for this trait may be important for development of high yielding hybrids from these inbreds or populations derived from these inbreds. The failure to detect SCA effects or interaction with environment for ears per plant indicates a selection scheme such as mass selection should be effective in changing this trait within derived populations, but the results indicate prolificacy may be undesirable within the earlier hybrids.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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