Genetic Analysis and Gene Mapping of Multi-tiller and Dwarf Mutant d63 in Rice

A spontaneous mutation, tentatively named d63, was derived from the twin-seedling progenies of rice crossed by diploid SARIII and Minghui 63. Compared with wild-type plants, the d63 mutant showed multiple abnormal phenotypes, such as dwarfism, more tillers, smaller flag leaf and reduced seed-setting rate and 1000-grain weight. In this study, two F2 populations were developed by crossing between d63 and Nipponbare, d63 and 93-11. Genetic analysis indicated that d63 was controlled by a single recessive gene, which was located on the short arm of chromosome 8, within the genetic distance of 0.40 cM from RM22195. Hence, D63 might be a new gene as there are no dwarf genes reported on the short arm of chromosome 8.