QTL Mapping And Genetic Analysis Of Tiller Angle And Rachis Branch Angle In Oryza Longistaminata

Rice is the staple food for about half of the world population,how to improve the yield of rice has been the focus of scientific research and breeding.Plant type and panicle type were two agronomic traits related to rice yield,among them,tiller angle directly related to rice plant type,branch angle closely related to panicle density.Thus,tiller angle and branch angle are two important agronomic traits.We hybridized a wild rice Oryza Longistaminata with a japonica cultivar Zhonghual 1 to generate F2 population,and measured the tiller angle and branch angle of each plant.Using 125 polymorphic molecular markers which uniformly distributed in the whole genome,we constructed the genetic linkage map of this population.Association analysis of tiller angle and branch angle with Inclusive Composite Interval Mapping and their phenotypic data.The results of this study shown as follow:1?There are significant differences in tiller angle and branch angle between a wild rice Oryza Longistaminata and Zhonghua11,the tiller angle was 41.67 degrees and 4.22 degrees,respectively.Tiller angle and branch angle in the F2 population were shown continuous distributions,it't indicated that quantitative inheritance of these traits.2?Genetic linkage map was constructed by using a total of 125 Polymorphic markers were screened from 930 InDel dominant markers throughout the whole genome.The number of markers per linkage group was 7-14,the length between 80.14cM and 156.58cM,the total length of the map was 1455.3cM,the average distance between markers was 11.6cM.3?3 QTLs for tiller angle were detected(qTA-1-1?qTA3-1 and qTA-7-1),were mapped on chromosome 1,3 and 7,respectively,and the these QTLs accounted for 20.98%of the genotypic variation.qTA-1-1 is a novel locus controlling tiller angle,which can explain 6.41%phenotypic variation.qTA-7-1,accounting for 7.84%of the phenotypic variation,contains the PROG1 gene that controls the tiller angle of O.rufipogon.There are one 18-bp InDel,18-bp InDel,two 3-bp InDels and five SNPs in the coding region of the PROG1 between Zhonghual 1 and O.Longistaminata,which cause the diffrerence of coding proteins.4?3 QTLs for branch angle were detected(qBA-2-1?qBA-4-1 and qBA-7-1),were mapped on chromosome 2,4 and 7,respectively,and the these QTLs accounted for 19.58%of the genotypic variation.Among them,qBA-2-1 and qBA-7-1 are novel locus controlling branch angle,the other was located at the same loci as the previous reported cloned or fine mapped QTLs harbored or located at their vicinity.In this study,main QTL of tiller angle and branch angle were not detected,QTLs were distributed on different chromosomes for tiller angle and rachis branch angle.we constructed the first molecular genetic linkage map of O.Longistaminata and explored new QTLs controlling tiller angle and branch angle,which laid a foundation base for further fine mapping and help breeders to develop new cultivars with ideal plant architecture using molecular-marker assisted selection.