76 Adjusting rice grain quality through induced mutation.

J. Neil Rutger. Dale Bumpers National Rice Research Center, USDA, ARS, Stuttgart, AR.

Induced mutation may be used to genetically improve rice quality by beneficially modifying grain quality characteristics of agronomically suitable varieties. Examples are: the induction of waxy grain mutants in the best agronomic varieties; selection of slender grain mutants in bold grain Green Revolution varieties; and induction of a low phytic acid mutant in the popular long grain variety Kaybonnet. On-going opportunities include induction of fatty acid variants in leading varieties, and other grain quality mutants that could be detected if efficient screening techniques are available. Another useful application of induced mutation is to beneficially modify agronomic characteristics of varieties with suitable grain quality. Examples are: induction of semidwarf Calrose 76 from tall Calrose; early flowering mutants from late Calrose; induction of semidwarf and early flowering mutants of tall, late basmati rice; and hybridization of semidwarf and early flowering mutants of a variety to produce recombinants with both improved agronomic characters, but without affecting the original grain qualities. On-going opportunities include induction of semidwarf and early flowering mutants in jasmine rice, followed by hybridization to obtain semidwarf, early flowering recombinants with jasmine quality.