EVALUATION AND UTILIZATION OF NOVEL GENETIC VARIATION IN RICE FOR THE ENHANCEMENT OF AGRONOMIC PERFORMANCE AND GRAIN QUALITY

Objective 1: Characterize the effects of novel mutations in known genes on their associated target traits (e.g., seed yield, seed morphology, grain quality, and arsenic accumulation). Subobjective 1A: Identify phenotypes resulting from mutations in starch biosynthesis- related genes, and determine their effect on grain quality and potential utility for developing new products. Subobjective 1B: Characterize the effect of mutations in silicon/arsenic transporters on the uptake and accumulation of these elements in rice. Objective 2: Identify the underlying mutations responsible for novel grain quality, agronomic performance, and stress tolerance-associated phenotypes (e.g., cold, drought, and/or heat) in induced rice mutants. Subobjective 2A: Identify the mutations responsible for opaque, non-waxy grain phenotypes and evaluate these mutants for alternative uses. Subobjective 2B: Identify mutations responsible for reduced cuticle wax phenotypes (wax crystal-sparse leaf mutants) and conduct a detailed characterization of the wsl mutants including an evaluation of their performance in the field and response to various biotic stresses. Objective 3: Screen established rice mutant populations, using forward and reverse genetic approaches, to identify new novel mutations that impact agronomic performance, grain quality, and reproductive cold tolerance in rice. Subobjective 3A: Identify mutants with altered uptake, transport and accumulation of nutrients, metabolites, and other compounds affecting agronomic performance and grain quality. Subobjective 3B: Evaluate agronomic and grain quality traits in fixed mutant lines grown under field conditions.