Project Number: 6225-21220-002-00
Project Type: Appropriated

Start Date: Jun 10, 2004
End Date: Oct 31, 2008

Objective:
Characterize rice genome in order to develop useful molecular strategies to accelerate the production of improved rice germplasm. Molecular genetics, molecular cytogenetics and molecular plant pathology approaches will be used to address four integrated objectives: 1) mapping and genomic analysis of disease resistance and end-use quality genes in rice for use by US rice researchers, 2) introgressing novel disease resistance genes from the wild Oryza species into cultivated rice for use by US rice breeders and identifying genetic stocks for use by rice researchers, 3) determining allelic variation of Pi-ta for identification of new sources of resistance; identifying the interaction components in the Pi-ta gene-mediated signal recognition and transduction pathways for precisely engineering resistance, and analyzing structural and functional relationships of AVR-Pita for predicting the stability of blast resistance in current cultivars, and 4) identifying differentially expressed genes after rice is infected with either the rice blast fungus or sheath blight fungus in order to develop strategies that will improve resistance in enhanced rice germplasm.

Approach:
Develop molecular markers associated with the economically important traits of a) disease resistance, with emphasis on rice blast and rice sheath blight and b) end-use quality, with emphasis on starch biosynthesis, which will improve identification of these traits in rice germplasm and promote the usefulness of marker-asisted selection in developing improved rice germplasm. Molecular markers will allow more efficient incorporation of Oryza spp. DNA into cultivated rice and can be used to further identify Oryza spp., backcross progenies, RILs, and genetic stocks. Characterize the Pi-ta gene-mediated signal transduction pathways which will aid in the development of both conventional and novel strategies to improve blast resistance for US rice germplasm. Identify differentially expressed genes upon pathogen attack to enhance understanding of the molecular mechanisms of interactions of necrotrpohic fungal pathogen and host. This may lead to the development of molecular markers for marker-assisted selection.