Semidwarf gene sdk has pleiotropic effects on rice (Oryza sativa L.) plant architecture

摘要

Ideal plant architecture has become a significant objective in high-yield rice breeding. In this study, a new semidwarf gene in sdk, a spontaneous dwarf mutant of Kasalath', was characterized and genetically mapped. The mutant has smaller panicles and seeds, reduced awns, and is 6-8days earlier in heading than Kasalath'. There was no significant difference in number (No.) of seeds and fertile seeds per panicle. Genetic analysis indicated that the dwarf character of sdk is controlled by a recessive gene, semidwarf k (sdk). From a segregating population of about 65000 individuals, 4987 sdk-type individuals were sampled. Gene sdk was located in a genomic region of 2622kb flanked by markers R-12 and R-43 in the centromeric region of chromosome 2. The results provide an opportunity for gaining an understanding of the molecular mechanisms underlying sdk and opening possibilities for its use in rice breeding programmes.