PHENOTYPIC DIVERSITY OF 188 RICE EMBRYO MUTANTS

We have identified 188 embryo mutants of rice and characterized them i nto six groups based on their phenotypes: (1) embryoless in mature see d, (2) deletion of embryonic organ(s), (3) abnormal position of embryo nic organs, (4) abnormal embryo size, (5) defect in organ morphology, and (6) variable abnormal phenotypes in spite of single mutations. Thr ee types of organless mutants are obtained: small globular embryo, clu b-shaped embryo, and large embryo. Although 12 shootless mutants deriv ed from at least three loci are identified, only three radicleless mut ants are recovered, which produce normal adventitious roots after germ ination. In reduced embryo mutants, every embryonic organ is reduced, in contrast to giant embryo mutants in which only scutellum is enlarge d. Considerable number of mutants are categorized into (5) and (6) in the above. These diverse embryo mutants would serve as promising mater ials for genetic study of embryogenesis. (C) 1995 Wiley-Liss, Inc.