Project Number: 6225-21220-001-00
Project Type: Appropriated

Start Date: Apr 12, 2003
End Date: Aug 31, 2005

Objective:
Develop a regional distribution map of red rice biotypes, determine propensity of these plant types to intercross with rice, and develop phenotypic and marker classifications. Improve the long-term sustainability of weed control with reduced inputs by discovering, developing, or improving rice germplasm that suppresses barnyardgrass with minimal herbicide application. Identify aphid-resistant rice lines and correlate the heritable hypersensitive response with resistance. Develop a new technique to measure carotene non-destructively in single rice grains, provide evidence of induction of carotene synthesis in rice endosperm, and provide materals that improve our understanding of the pigment composition in rice grains.

Approach:
Red-rice-contaminated rice samples from Arkansas, Missouri, and, if feasible, Mississippi, Louisiana, and Texas will be collected from commercial rice mills to supplement existing red rice collection. Plants will be grown from single seeds and phenotyped in 'quarantined' field plots at Stuttgart which will then be genotyped by microsatellite marker analysis. Field experiments will be conducted with herbicide-resistant or non-resistant rice to detect reciprocal outcrossing between rice and red rice. Replicated field experiments will be established to quantify natural levels of barnyardgrass suppression using selected high yielding indicas or indica crosses, selected crosses between tropical japonica lines and weed suppressive lines, and appropriate commercial tropical japonica cultivar standards. Germplasm will be generated through traditional breeding or induced mutation. A variety of rice lines will be screened for resistance to three local aphid populations in order to identify susceptible and resistant rice lines. Fluorescence spectroscopy will be used to detect the presence of carotenes non-destructively in single grains of rice. This method has not been used previously to measure carotenes, and parameters and standard curves will be determined.

Project Team

Gealy, David Miller, Helen

Project Annual Reports

FY 2003