Heading Characteristics And Molecular Phylogenetic Analysis Of Related Genes Of Weedy Rice In Northeast China

There are significant differences in growth period and heading date among cultivated rice and its companion weedy rice in Northeast. This universality divergence is the result of ecological adaptability of natural selection of weedy rice. To further clarify the genetic basis of northeast weedy rice heading date is important for further understanding of the mechanisms of evolution of weedy rice, rice species ecological adaptability, genome research and it has a high value for the response of choice, as well as rice weed control.This study investigate the heading day of 37 northeast cultivated rice and 48 associated weedy rice to clarify the characteristics of weedy rice heading date. Genotyped those heading date related functional genes, initial screening possible response genes by related analysis between heading phenotype and heading day.Establish phylogenetic relations between weedy rice and different types of Asian cultivated rice in the target gene interval by using specific length amplified fragment sequencing (SLAF-seq) from 282 different types of Oryza sativa to find the selection mark in weedy rice target genes and understand the genetic basis of heading divergence among northeast cultivated and weedy rice.The main results are as follows:1. There is a strong divergence heading date between northeast japonica and weedy rice. The majority of weedy rice in the Northeast heading early than japonica under long-day conditions when they are cultivated in same place of Northeast, when in Hainan short day conditions both heading date are roughly equivalent and both are shorten. Northeast japonica showed photoperiod sensitive while weedy rice showed inert, most japonica heading day was promoted under short-day conditions, but not weedy rice.2. In this study, a total of six heading date related alleles between 37 northeast cultivated rice and 48 associated weedy rice were sequenced, including Hd1, Ghd7, Ehd1, DTH2, Hd3a and RFT1. Up to 10 kinds of genotypes Hdl. In this study, we find two new alleles of Hdl in weedy rice, which was contributed to heading date difference between japonica and weedy rice. The other five genes was not found new types of alleles. Ghd7, DTH2 which control the rice heading upstream of the gene net, and downstream Hd3a having a certain percentage of the difference genotype between two populations, but heading phenotypic variation no significant correlation. RFT1 and Ehd1 between the two populations consistent genotype, and heading has no divergence.3.1 Mb interval of heading date key genes phylogenetic analysis of282 samples molecule show that the genes are located upstream of heading genetic regulatory network Ghd7. Hd1 and DTH2 between northeast japonica and associated weedy rice have different degrees of divergence on the system evolution, and weedy rice has a genomic imprinting of low latitudes Rice. Cultivated rice and associated weedy rice are having a same cluster from the upstream of gene network Ehd1 and downstream Hd3a and RFT1.4. Each group material nucleotide diversity (Ï€) scan by 500kb showed, in the upstream Hdl genomic region, northeast weedy rice by the relative strength of natural selection is 3.33 times of cultivated rice. Northeast japonica and associated weedy rice has no significant difference of genetic diversity in he region 1Mb in the degree of similarity select suffered on Hd3a and RFTl genes5. Previous studies have shown that, Hdl under short-day conditions can promote heading, while suppressing rice heading under long-day conditions. The two new alleles of Hd1 may promote weedy rice heading earlier than cultivated rice under short-day conditions, and is a natural choice of target genes, which further understanding of ecological adaptability of weedy rice has certain research value.