RICE MUTANT LINES LACKING ALPHA-GLOBULIN

In the screening of rice mutants having altered seed protein compositi ons, two mutant lines lacking alpha-globulin were selected from the Ma seeds of a white panicle mutant of cv. Koshihikari irradiated with ga mma-rays. The mutant character, lack of alpha-globulin, was found to b e controlled by a single recessive gene. Northern blot analysis of end osperm RNA using the probe of alpha-globulin cDNA revealed that the al pha-globulin gene is not expressed in the alpha-globulin-less mutants. The mutated gene was considered to be alpha-globulin gene, and named glb-1(t). RFLP analysis of F-2 plants between the mutant and indica cu ltivar 'Kasalath' using land marker probes suggested that glb-1(t) is on chromosome 5 and that the distances of glb-1(t) from the markers, C 246 and X'Npb366, were 15.4cM and 30.8cM, respectively. The mutant lin e lacking alpha-globulin was expected to have a higher content of lysi ne in rice grains, but the lysine content of the mutant line was found not to be higher than the original cultiver. The possible use of the mutant as a breeding material is discussed.