Start Date: Jun 23, 2008
End Date: Sep 30, 2011
Additional germplasm and data will be added to the NSGC rice collection for distribution to the public via GRIN. The Core collection will be characterized for sheath blight disease resistance, grain mineral accumulation, straighthead tolerance, protein content, and cold tolerance, and genetic markers will be identified that are associated with these traits. The Genetics Stocks Oryza (GSOR) collection will be expanded to 15,000 accessions that are curated and distributed to the research community through a searchable on-line database. Selected accessions from the NSGC collection will be evaluated for health- beneficial compounds like polyphenols, flavonoids, and carotenoids, and the influence of the environment and processing methods on levels of these compounds will be evaluated. Germplasm will be evaluated under flooded and aerobic conditions to understand the genetic mechanisms controlling nutrient uptake. Mapping populations will be developed,and rice gene microarray chips will be used to identify chromosomal regions associated with nutrient uptake. The genotype x environment interaction on key enzymes in the starch pathway will be studied to determine how they impact starch structure and processing quality. In an effort to understand how rice quality will be impacted by crop rotation systems, 5 to 10 rice cultivars will be grown using conventional tillage/no-till, permanent flood/intermittent-flushing, different fertilization rates, and different crop rotations, and agronomic and cooking quality traits will be evaluated to provide insight as to how changing cropping systems will impact rice milling and cooking quality. Novel genes for blast and straighthead disease resistance will be identified using mapping populations. Markers and germplasm will be released to breeders for developing improved cultivars. Sequence variation around a SNP in exon 10 of the rice Waxy gene will be evaluated to determine what impact it has on RVA paste viscosity characteristics. Genetic markers will be developed that can be used in breeding for elevated pasting profiles, which is desired for rice used in canning, instantizing, and other food preparation processes. We will fine map several QTL previously identified to be associated with grain chalk. Progeny from the selected recombinant lines will be grown in two environments and chalk amounts quantified with a Winseedle Image analysis system. Segregation of tightly linked SSR and SNP markers will be analyzed to pinpoint recombination points and candidate genes in the finely mapped region. Genetic markers developed from this research will be used by breeders to develop new cultivars that have greater translucency, higher milling yield, and consistent cooking quality.