Wednesday, November 7, 2007
279-14
Descriptor Associations in the USDA Rice (Oryza sativa L.) Germplasm Collection and a Core Subset.
Hesham Agrama1, Wengui Yan1, Ming-Hsuan Chen2, and Anna Mcclung1. (1) USDA-ARS, 2890 Hwy 130 East, Stuttgart, AR 72160, (2) USDA-ARS Rice Research Unit, 1509 Aggie Drive, Beaumont, TX 77713
Trait association has long been used in plant breeding and production practices, and information about descriptor association in the USDA rice germplasm collection is very limited. All the accessions which have been evaluated for the 14 important descriptors in the USDA rice whole collection and core collection were used for the correlative analysis. The two collections were analyzed with Newman–Keuls test, Shannon–Weaver diversity index and Wilcoxon rank-sum non-parametric test for data understanding. Late maturing rice had tall plant height, long, thin and light kernels, and high amylose content. Tall rice matured late, lodged easily and had long and thin kernels, high chance for red kernels, and high amylose, but low alkali spreading value (ASV). Lodging was primarily associated with plant height, and also with plant type, kernel length, bran color, hull color, amylose and ASV. Cooking quality associated with grain type, which is shaped by breeding for market requirements, was verified, and also was related to maturity, plant height and plant type. Red bran rice was verified to be related to tall plant, hull color, awn and lodging, and also associated with panicle type, kernel length and weight, amylose and ASV. These relationships should be valuable in facilitating identification of useful traits economically and expeditiously for use in rice improvement by breeders and geneticists.