Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 8, 2007
Publication Date: November 1, 2007
Citation: Agrama, H.A., Yan, W., Chen, M.H., Mcclung, A.M. 2007. Descriptor associations in the USDA rice (Oryza sativa L.) germplasm collection and a core subset. [abstract] American Society of Agronomy, New Orleans, LA, November 4-8, 2007. p. 279-14. Technical Abstract: Trait association has long been used in plant breeding and production practices, however information about descriptor associations in the USDA rice germplasm collection is very limited. All accessions which have been evaluated for 14 important descriptors in the USDA rice whole collection and the core collection were used for the correlative analysis. The two collections collections were analyzed using Newman-Keuls test, Shannon-Weaver diversity index and Wilcoxon rank-sum non-parametric test. Late maturing rice cultivars had tall plant height, long, thin and light kernels, and high amylose content. Tall rice accessions lodged easily, had high chance for red kernels, and low alkali spreading value (ASV). Lodging was primarily associated with plant height, but also with plant type, kernel length, bran color, hull color, amylose and ASV. Cooking quality associated withy graint ype, which is shaped by breeding for market requirements, was verified, and also was related to maturity, plant height and plant type. Red bran rice cultivars were associated with tall plant height, awns, and lodging. These relationships are valuable for identification of germplasm with desirable traits for use in rice improvement programs by breeders and geneticists.