Abstract:

A new long-culm mutant “D111” was discovered in breeding materials of rice (Oryza sativa L.). Polymorphic analysis of microsatellite markers demonstrated that D111 derived from a gene mutation in the crossing progenies of two semidwarf varieties 6442S-7 and Shuhui 881. Plant height and culm length of D111 increased by 63.0% and 87.0%, respectively, compared with those of its parent Shuhui 881. Genetic analysis suggested that the long-culm trait of D111 was controlled by a pair of dominant genes, and the long-culm gene of D111 was tightly linked or allelic to that of long-culm control variety Nanjing 6. Molecular marker analysis showed that the mutant gene of D111 located on the long arm of rice chromosome 1, 27.7 cM, 25.5 cM and 6.0 cM from microsatellite markers RM212, RM302 and RM472, respectively. This long-culm mutant gene was designated tentatively as LC (t). It was considered that D111 was the first rice example of dominant long-culm mutant derived from spontaneous mutation of semidwarf varieties and that LC(t) was the first mapped long-culm mutant gene of rice. In addition, the possible relationship between LC(t) gene and rice “green revolution gene” sd1 was discussed.

Key words: rice (Oryza sativa), dominant long-culm mutant, long-culm gene, genetic analysis, gene mapping, microsatellite marker