Abstract
During fine structure analyses of artificially induced waxy mutants in maize by use of Nelson's pollen analysis methods, it was noticed that some mutants showed a phenotype intermediate between waxy and normal nonwaxy. Such intermediate or leaky waxy mutants were frequent among mutants induced by a chemical mutagen, EMS. They seemed to be located evenly within the waxy locus. This would suggest that they might have been missense mutations, which would produce full-sized but partially inactivated enzymes, rather than deletions or frameshift mutations. To confirm the intermediate phenotype, a rapid measuring system was developed to measure waxiness of endosperm quantitatively. It was based on the blue value method and is applicable to a single grain of rice. Among the 27 waxy mutant lines of maize, including 11 EMS-induced, two of the EMS-induced mutants were clearly intermediate. Eighteen EMS induced wx mutants of rice were also examined, and nine were intermediate.