Rice Dwarfing Package Spike Mutations A Body Dsp1 Genetic Analysis And Gene Mapping

Creation of mutant pool in rice provides a great resource platform for molecular biology and breeding studies . Based on the construction of the mutant pool, it is the most important thing to identify/utilize mutants, to clone the related genes, to elucidate their molecular machenism and regulation pathway. In the middle of the 20th century, the use of sd1 gene in rice breeding makes the first breakthrough in yield. Morphogenesis of rice floral organs determines the level of rice yield, too. Thus, it is beneficial to further improving the rice yield through the dissection of formation machenism of dwarf and panicle morphogenesis in rice. In addition, as the most important food crops in China, rice holds the smallest genome and a wide range of collinearity with other cereal crops. Discovery and cloning of new genes have a universal significance for the growth and development of cereal crops .In this research, we found a novel dwarf mutant, named dwarf and sheathed panicle1(dsp1), from Japonica variety Nipponbare treated with Ethyl methanesulfonate (EMS). The main phenotype of the dwarf mutant was dwarf,and sheathed panicle.1. Genetic analysis of dsp1 mutant. During the heading stage, the individual plants in the F1 and F2 progenies from the crosses between dsp1 heterozygotes and each of TN1 and Minghui63 were investigated. In the two F1 plants between the wild type and dsp1, all plants exhibited wild-type phenotype, suggesting that the mutant trait is recessive. Second, in the two F2 populations, both the segregation rates of wild-type and dwarf plants are in accordance with a 3:1 ratio. Therefore, the dwarf trait is controlled by one recessive gene.2. Fine mapping of DSP1gene. To elucidate the molecular function of DSP1, the DSP1 gene was finemapped by a map-based approach. The DSP locus was located on chromosome12 by rough mapping. We further narrowed the DSP1 gene to a ~56 kb interval by using SSR, STS and CAPs markers. Eight open reading frames (ORFs) were predicted within this region.