Study On Floral Traits,Seed Setting Characteristics And Genetic Diversity Of Hainan Ommon Wild Rice(Oryza Rufipogon Griff.)

In this study, Hainan common wild rice (Oryza rufipogon Griff.) were tested for the floral traits and seed setting characteristics of self-pollination and outcrossing characteristics, comparison of different combinations of common wild rice by cultivated rice (Oryza sativa L.), and evaluating the differences and causes of the gene flow frequencies. A detecting technology based on fluorescence-based SSR marker and capillary electrophoresis was adoptd to analyse genetic diversity of Hainan common wild rice. Further, the relationship genetic diversity and gene flow frequency could be described. Agronomic traits of different hybrid offspring of common wild rice and cultivated rice were observed to show the fate of the gene in offspring of common wild rice and cultivated rice or transgenic rice. It provides the basis for gene flow effects and a reference for hybrid rice breeding. The results showed as followes:(1)The floral traits and seed setting characteristics of self-pollination:the mean length and width of anther and stigma, area and volume of anther, pollen amount, surface area and volume of stigma, length stigma and style, span and angle of stigma of Hainan common wild rice tested were larger than that of cultivated rice. On the contrary, fertility, viability, size, area and volume of pollen, and seed setting rate of self-pollination of Hainan common wild rice were less than that of cultivated rice. No significant difference showed between floral trait and seed setting rate of self-pollination of common wild rice in Guangxi and Hainan.(2) The outcrossing and seed setting characteristics of self-pollination:The variation range of outcrossing rate of all hybrid combinations was0-18.02%, the mean was2.24%. The hybridization affinity of different populations of Hainan common wild rice and the same cultivated rice was different, so was the different cultivated rice and the same population of common wild rice. No significant difference showed between floral trait of pistil and the outcrossing characteristics of Hainan common wild rice. The correlation between outcrossing traits and seed setting characteristics of self-pollination was not significant.(3) The genetic diversity and genetic structure of Hainan common wild rice:The total range of genetic variation in populations diversity ΗT=0.120(Xrem3)-0.929(RM297) with an average of0.777, the scope of diversity of genetic variation within populations Ηs=0.118(Xrem3)-0.737(RM282), which indicates a high level of genetic diversity in the total population of12common Hainan wild rice populations. Number of alleles (Na) of12populations of common wild rice ranges from2.318(SY)0.727to7.955(LS), effective number of alleles(Νe) ranges1.773(SY)-4.293(WC), Shannon index variation ranges Ι=0.585(SY)-1.513(LS), the actual observed heterozygosity Ηo=0.531-0.770, the average expected heterozygosity He=0.315-0.679, from the results described above, it can be drawn that the Genetic diversity of wild rice in North and Southeast regions is more abundant, the genetic diversity of the Southern District of Sanya was not rich enough. Furthermore, the genetic diversity was more abundant, gene flow frequency was lower by the analysis of genetic diversity and gene flow.(4) The agronomic traits of hybrid offspring of common wild rice and cultivated rice: The mature period of hybrid offspring have two kinds:one was matured in June, referred to as the "mature in summer ", and another in November to December, referred to as the "mature in autumn". Compared with F1plants matured in Summer, which matured in Autumn were higher and had secondary tillers, the number of tiller and effective tiller were more, but they had longer growth period, longer ear length and longer flag leaf ligule. The100-grain weight, seed setting rate and the grain straw ratio of F1plants matured in summer which was larger than the average of seeds matured in autumn. The type of the grain matured in Summer was elliptic and long, while that most matured in Autumn were long and slender, and the grain color of plants matured in Summer was mainly yellow, while the grain color of plants matured in Autumn was straw yellow, brown or black, mainly in black, and the grains were easy to scatter, It indicates the agronomic traits of panicle tends to common wild rice.