Heritability and Combining Ability for Gossypol Content in Six Lines of Upland Cotton1

Abstract

Six lines of upland cotton (Gossypium hirsutum L.), selected for different levels of gossypol and other terpenoids in flower buds, were intercrossed in all combinations, including reciprocals. Parents and F1 hybrids were grown in a complete diallel set with three replications m one environment. Analysis of variance of gossypol level, using the methods of Grilling, revealed a large and highly significant component for general combining ability, and a small nonsignificant component for specific combining ability. There was also a very small, but significant, estimate for reciprocal effects. We concluded that gossypol in flower buds is inherited in an additive manner (94% narrow sense heritability) and should thus be readily selectable.Analysis of the same materials using Hayman's technique confirms the highly significant and predominant additivity of inheritance, but also suggests that dominance cannot be completely ruled out as a source of significant variation.