Record Details
The evaluation of heterosis for grain yield, total leaf area and malting quality in 21 spring barley crosses
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The evaluation of heterosis for grain yield, total leaf area and malting quality in 21 spring barley crosses |
| Names |
Carleton, A. E. (Albert Eugene), 1940-
(creator) Foote, Wilson H. (advisor) |
| Date Issued | 1966-03-03 (iso8601) |
| Note | Graduation date: 1966 |
| Abstract | The purpose of this study was to determine the amount of heterosis in three complex traits in barley and to investigate the concept of component interaction as a means of producing heterosis. The complex traits were grain yield, total leaf area, and malting quality. Seven varieties of spring barley were crossed in all possible combinations in the spring of 1963, The following year, the 21 F₁'s and seven parental varieties were space planted in a replicated, randomized block design in a greenhouse groundbed on the campus of Oregon State University. Since three of the seven parents were six-rowed barleys (Hordeum vulgare L., emend. Lam) and four were two-rowed barleys (Hordeum vulgare L., emend. Lam) , crosses within and between six-rowed and two-rowed barleys were included in this study. The 21 crosses were separated according to their respective parental row numbers throughout this study. The evaluation of heterosis for the complex traits was made by the component approach. The amounts of heterosis for the complex traits were related to the expression of heterosis of their components. The association between components and the complex traits and between the different components, were determined by computing simple correlation coefficients. The direct and indirect relationships of the components to the complex traits were further analyzed by path coefficient analyses. Estimates of the type of gene action present for the complex traits, as well as for their respective components, were made by computing general and specific combining ability estimates and narrow-sense heritability estimates. Heterosis may occur in a complex trait even though none of the components of the complex trait exhibit heterosis. This situation has been called component interaction. When parental varieties do not differ in the complex trait but possess large differences in the components of the complex trait, component interaction may occur in the hybrid to produce heterosis in the complex trait. Additive expressions for the components in the hybrids of such parental varieties may result in the hybrids exceeding both parents in the complex trait. Large differences in the components of the three complex traits were found to exist among the parental varieties in this study while the parental varieties were not greatly different in the complex traits. These findings would suggest that component interactions were likely to occur in the hybrids produced by crossing the parental varieties. However, in this study, the expression of heterosis for the three complex traits was limited, with only a few crosses expressing a substantial amount of heterosis. The lack of heterosis, particularly in those crosses where the largest differences in the components existed between the parental varieties, could be ascribed to the failure to obtain an additive expression in the hybrid for the most important components. The relationships between the components of the complex traits also indicated that the components were not completely independent. The lack of independence of the components could also prevent component interactions. There were several crosses which did exhibit component interaction in the expression of heterosis for the complex trait but these were relatively few in comparison to those which did not exhibit component interaction. Estimates of gene action, in general, were in agreement with the observations of heterosis. Those traits which exhibited the most heterosis were found to be controlled mainly by non-additive gene action white those traits exhibiting a slight amount of heterosis were found to have large additive gene action estimates associated with them. |
| Genre | Thesis/Dissertation |
| Topic | Barley -- Breeding |
| Identifier | http://hdl.handle.net/1957/48360 |
