Study On Genetic Diversity On ORFs Regions And Indica-Japonica Consanguinity Differentiation Of Weedy Rice

In order to explore the genetic diversity at ORFs levels and indica- japonica consanguinity proportion in-depth of 47 weedy rice. In this article,47 weedy rice were studied, which chose from resourses matrrials by investigating in fleld. The research based on the level of open reading frame to analysis genetic diversity of weedy rice which distribution in major rice areas of China by SRAP; and indica- japonica blood differentiation of weedy rice to quantified, which depended on specific markers of InDel (Insertion/Deletion) and SSILP (Subspecies-specific Intron Length Polymorphim). The origin study of weedy rice to provide a favorable basis for classification; Cheng's index investigated phenotypic traits of weedy rice, and also provided experimental evidences for population differentiation. The results showed that:1. SRAP is suitable for analyzing the genetic diversity of weedy rice. The result showed that PCR products can be successfully amplified by 110 pairs of primers. A total of 845 DNA bands were identificated after PCR amplified by PAGE electrophoresis and 590 of them were polymorphic. The percentage of polymorphic rate was 69.82%. The average number of polymorphic bands was 5.4 per pair of primers.Genetic diversity analysis showed that Shannon-weaver information index of Weedy rice in our country was 0.63, while the North weedy rice diversity index (Ⅰ) was 0.62 and the South was 0.63.On the basis of genetic distance cluster analysis, significant genetic differentiation was detected between North and South weedy rice. But south weedy rice could be classified as indica rice(Oryza sativa L. sub. indica) and north weedy rice could be classified as japonica rice(Oryza sativa L. sub. japonica).2. The results of InDel and ILP were consistency. Based on Indica-japonica consanguinity differences by InDel and ILP.89 locus were selected depended on the genome sites of Indica- japonica differentiated, and they could successfully analysised these 47 resources weedy rice which collected from high incidence for paddy around. The results showed that weedy rice in China had a greater degree of differentiation of indica- japonica.There was indica-japonica differentiation in chinese weedy rice. Weedy rice japonica type gene frequency reached 0.99 in northeast; frequencies of Neimenggu as high as 0.94; and southern of Jiangsu, Shanghai and Guangdong were 0.05,0.43 and 0.05, respectively. Gene frequency of Japonica type cluster analysis showed that the similarity coefficient of 0.41 as the threshold value, indica and japonica varieties of species were relatively independent of population structure, the Northeast region of the weedy rice in the rice group together, Jiangsu and Shanghai were among the weeds of rice Japonica type or partial type.3. Cheng's index results showed that indica-japonica discrimination of weedy rice. Weedy rice were indica and partial indica in southern, and japonica and partial japonica in northern. That was to say weedy rice reached the degree of differentiation of indica and japonica. Morphological findings and SRAP molecular markers results were anastomosis, and with two specific markers (InDel and SSILP) were consistent.So that the existence of subspecies differentiation of weedy rice and cultivated rice were with the same geographical distribution.