Genetic Analysis And Gene Mapping Of The Tig1Mutant In Rice(Oryza Sativa L.)

Rice is one of the most important food crops in the world, as the model crop of monocots, rice floral organ development and molecular mechanism are always at the focus researchers of plant molecular biology, while the yield and quality characteristics will be appreciable impacted by the rice flower development.The development of the floral organ is an important stage between the vegetative growth and reproductive growth, researchers are screening the rice’s genomic library by the conserved the sequence of monocot development genes, and have got a lots of MAD-box genes, however, compared with the research of floral organ development model of the dicot, the research of rice and other monocots still lags behind relatively. For example, the relevant research about the A gene which has the function to adjust calyx and their homologous organs isn’t in-depth. The main limitation is lacking of points junction for characters, the exact function of majority gene are not sure. So creation and screening the floral organ mutations in relatively research have a very important significance.In this study, we found a tip grain mutant tigl in a M2population of Ningdao1after EMS-mutagenized. Then, create location group, which derives from the hybrid crossing parents (the Spikelet-Mutant in Rice Ningdao1and Suwangwanger). Observation and fine mapping the control gene, and the main results are summarized as the follows:First, tigl mutant structure observation and analysis:the lemma shape changes significantly at the spikelet mutant, force the grain becomes sharp, and mutation also forbid its forming a closed structure like normal glume. These changes lead directly to the grain weight and appearance quality significantly decreased.Second, genetic analysis and fine mapping of tigl mutant:Genetic analysis of the F2segregation populations, and after x2testing (x?=0.34<x20.05=3.84), confirms this mutant trait is controlled by a single recessive gene. According to the preliminary mapping and a large F3populations, the tigl mutant was finally narrowed down to a49.2kb at the interval of RM5421and RM14154on chromosome2through molecular biology skills. Third, prediction of tigl candidate gene:retrieval the information of rice genome sequence, we determine that there have six open reading frames (ORF) in the target range, which have three predicted gene expression information. Among them, LOC_Os02g56610encoding a248amino acid protein chains, including DUF640domain, through sequencing, we found that the mutation resulted in a two base pairs encoding regions of the gene mutation, wherein, one is nonsense mutation, but another point mutations leading to its premature translation termination, causing heritable variation at glume shell, ultimately determine the LOC_Os02g56610as the candidate gene.