Author
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Jaradat, Abdullah |
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Submitted to: Communications in Biometry and Crop Science (CBCS)
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/15/2011 Publication Date: 4/5/2011 Citation: Jaradat, A.A. 2011. Polymorphism, population structure, and multivariate relationships among secondary traits in open-pollinated corn heterotic groups. Communications in Biometry and Crop Science. 6(1):4-20. Interpretive Summary: Heterotic groups of open-pollinated corn varieties (OPVs) and their hybrids (OPVhs) gained increased interest among organic and low-input farmers due to their stable yields, broad adaptation, low-input requirements, quality traits and tolerance to adverse conditions. Polymorphism, population structure, and multivariate relationships among 34 secondary traits and their impact on grain yield were quantified in 46 OPVhs within eight maternal heterotic groups. Large levels of polymorphism and population differentiation especially for reproductive traits, and above average values for diversity indices, frequency of desirable trait variants, and population differentiation were found for almost all secondary traits. Maternal heterotic groups were identified as potential sources of desirable variants of single or multiple traits appropriate for adaptation to short-growing seasons, low-input farming and adverse environmental condition. The information on the variability available in these OPVhs is of value in pursuing breeding and selection objectives for organic and low-input farming and to help stabilize yield through increased diversity on the farm. Technical Abstract: Plant, ear and kernel traits directly or indirectly associated with grain yield in corn (Zea mays) were suggested as "secondary" traits to select for larger grain yield, especially in open-pollinated corn varieties (OPVs) and their hybrids (OPVhs). Thirty-four secondary traits, besides grain yield, were measured or estimated on 46 OPVhs in eight maternal heterotic groups (HGs) grown under four environments. For each trait, components of total phenotypic variance, polymorphic diversity index, and population differentiation were estimated and used to identify HGs with combinations of desired variants of secondary traits. Maternal heterotic groups were identified as potential sources of desirable variants of single or multiple traits appropriate for adaptation to short-growing seasons, low-input farming, and adverse environmental condition. |
