Interaction of Combining Ability Effects with Environments in Diallel Crosses of Upland Cotton (Gossypium hirsutum L.)1
- Joshua A. Lee,
- P. A. Miller and
- J. O. Rawlings2
Ten strains of Upland cotton, Gossypium hirsutum L., reperesenting a broad array of germ plasm, were crossedin all possible combinations, and the parents and F1 progenies were reared in replicated experiments at two locations in North Carolina for 2 years. Heterosis for lint yield, measured as departure from the average mid-parent value, was about 26% for the pooled experiments. Estimates of heterosis for boll size, lint percentage, and some fiber properties were small but significant. When summed over all environments, the estimate of general combining ability for lint yield was not significant. However, the interaction of general combining ability by locations for lint yield was significant. Significant estimates of general combining ability were obtained for boll size, lint percentage, and all fiber properties. None of the interactions of general combining ability by environments were significant for these characters. The estimate of specific combining ability for fiber yield, though fairly large, was not significant. Estimates of specific combining ability for lint percentage, boll size, and all fiber properties were not greater than zero. These results were interpreted to mean that no difficulties should be encountred in selecting for changes in fiber properties. Any gains realized should remain stable over the environments sampled. On the other hand, advances in fiber yield could be achieved only at individual locations and, even then, interactions with years and locations would reduce the effectiveness of selection. Some high-yielding combinations with desirable lint properties were detected.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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