Location Of Two Dominant Opposite Genes Of Maize By SSR Marker

The appropriate near isogenic line (NIL) and analysis population were constructed to screen SSR markers for two dominant opposite genes of maize. We primely located the two dominant opposite genes through linkage analysis in an F2 population with the stable polymorphic SSR markers. On the base of it we search for SSR markers nearby the linkage SSR markers and then screen them between the pools of the NIL again.We exactly located the two dominant opposite genes through linkage analysis in an F2 population with the stable polymorphic SSR markers. The results showed: 1. The genetics investigation indicated that there were two different dominant genes between the H14D opposite line and the H53 alternative line we constructed. The ratio of F2 population separation is 9 to 7.The two genes are independent and mutually complemental. 2. 7 couple stably polymorphic SSR primers such as bnlg1720, umc2094, bnlg1175,bnlg1831,umc1560, umc1627,bnlg128 were screened between the H14D opposite line and the H53 alternative line from 105 maize microsatellite primers which distribute equably on the ten chromosomes of maize.They distribute on the chromosome one,two,eight and nine respectively. 3. The linkage of the 7couple polymorphic primers was analyzed respectively with SSR PCR method within an F2 population of 441 individuals. The results revealed the microsatellite marker umc2094 is linked to the gene Opp₁ with the genetic distance 6.7cM, the marker bnlg1831 is linked to the gene Opp₂ with genetic distance 6.1 cM. 4. 13 microsatellite markers are chose near the umc2094 and bnlg1831 districts.We obtained 3 couple stable polymorphic microsatellite primers between the two pool lines screening. They are bnlg1092,bnlg1887 and umc1082. The linkage of the 3 couple polymorphic primers was analyzed respectively with SSR PCR method within the F2 population of 441 individuals. The results revealed the microsatellite marker bnlg1092 is linked to the gene Opp₁ with the genetic distance 12.2cM, the marker bnlg1887 and umc1082 were linked to the gene Opp₂ with genetic distance 16.8 cM and 1.9cM respectively. 5. The linkage relationship among 5 microsatellite markers was also analyzed: bnlg1092 and umc2094 belong to one linkage group with genetic distance 18.9cM and they locate in either side of the gene Opp₁ at the Bin2.01on the chromosome 2 of maize. bnlg1887,umc1082 and bnlg1831 also belong to one linkage group they locate at the Bin2.06 on the chromosome 2. Thereinto umc1082 and bnlg1831 locate in either side of the gene Opp₂ with genetic distance 8.0cM. Bnlg1887 and umc1082 locate the same side with genetic distance 14.9cM. To summarize, this paper makes a great progress in molecular markers and gene location to the two dominant opposite genes of maize. Several close microsatellite markers for the two opposite genes were obtained and they are located in either side of special microsatellite markers. The results established the foundation of Marker Assisted Selection(MAS) of breeding , the two opposite genes Map-based clone and function study of the gene.