Identification And Analysis Of Two Plant-type Related Genes In Rice

Rice (Oryza Sativa L.) plant architecture is an important basis to determine the potential yield, which is consisted of plant height, tillering, panicle type, leaf and other factors. The mutant of plant type is a significant material in rice functional genomics research. This article described the morphological identification, genetic analysis, and other related physiological traits of about two rice mutants, which related to plant architecture. The gene was mapped by positional cloning. These results enriched the study of plant type theory. The main results are as follows:1. The dwarf mutant for this research has derived from SN9816 by spontaneous mutation, named SN9816d. The mutant showed lower plant height, higher number of tillers, thinner and longer flag leaf, and poor fertility compare to wild type. In addition, number of spikelets per panicle, number of unfilled grains per panicle, grain length, grain weight, grain thickness and 1000-grain weight decreased obviously. The number of secondary branches was significantly higher than the wild type, but the number of primary branches has no significance difference. Genetic analysis showed that the dwarf phenotype was controlled by a single recessive gene. The SN9816d was eventually mapped to a 139.186kb region between MM4428 and MM 13672 on the chromosome 2 by Map-Based Cloning.2. Tillers and effective panicles are important factors for yield of rice which control by quantitative trait locus. The high-tillering mutant for this research was derived from SN205 by spontaneous mutation, named SN205ht. In this research, we constructed F2 mapping population by a cross between Japonica SN205ht and LTH. There was an extreme difference in the number of tillers between SN205ht and LTH. The QTL of tillers were mapped by constructing genetic maps. For now we constructed 190 F2 mapping population, and then constructed a genetic map which contain 88 SSR markers and covers 12 chromosomes. The statistic QTL ICI Mapping v3.0 software was applied to detect QTLs,5 QTLs were found which related to tiller, covering chromosomes 1,2,6,7,11. One major QTL was detected and located on qTNl of chromosomes 1. The phenotypic variance was 51.97%. Narrow down the genetic distance, and finally the major QTL-qTN1 was mapped between MM 10386 and MM1616. The physical distance was 1176.14kb.