|Neves, Pericles C|
Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/1/2007
Publication Date: 10/15/2007
Citation: Eizenga, G.C., Agrama, H.A., Prasad, B., Bryant, R.J., Neves, P.F., Mackill, D.J. 2007. Developing mapping populations between U.S. rice cultivars and selected O. nivara accessions. 5th International Symposium of Rice Functional Genomics, Tsukuba, Japan, Oct. 15-17, 2007. PO-073.
Technical Abstract: Rice wild relatives (Oryza spp.) often contain novel traits, especially for tolerance to biotic and abiotic stresses, which would be valuable to incorporate into rice (O. sativa) cultivars adapted to the USA. Using the advanced backcross method, a BC2F2 population of 192 families was developed from a cross between the popular U.S. medium-grain, temperate japonica cultivar M-202 grown in California, and O. nivara (IRGC 100195). These families were evaluated for seedling vigor and agronomic traits at Davis, California. Subsequently, 175 BC2F4 families from this population were evaluated for agronomic and grain quality traits at Stuttgart, Arkansas and genotyped with 155 SSR markers distributed throughout the entire rice genome. Putative QTL for vegetative, agronomic and grain quality traits were identified. In a separate study supported by USDA/CSREES-RiceCAP, two different BC2F2 populations were developed from a cross between the popular southern U.S. medium-grain, tropical japonica cultivar Bengal and two O. nivara accessions (IRGC100898, IRGC104705) identified as having sheath blight resistance. Approximately 300 families were selected based on seed set and genetic diversity, for genotyping with a diverse set of 200 SSR markers and evaluating sheath blight resistance by rating the plant’s reaction to the fungus, Rhizoctonia solani, which causes rice sheath blight disease. These results will be used to identify sheath blight resistance QTL. When these projects are completed, the mapping populations will be available to the public through the USDA-ARS Genetic Stocks-Oryza (GSOR) collection (http://ars.usda.gov/spa/dbnrrc/gsor). Other mapping populations and mutants stocks available through GSOR will be described.