Fine Mapping Of Scattered Gene LAZY3 In Rice

Rice is the most important grain crop in the world.Increasing the rice yield has attracted much more attention.Ideal plant type can increase rice yield by increasing rice yield per unit area.Tiller angle and tiller number are two important elements of rice plant type,which are closely related to planting density and effective panicle number of rice,respectively.Spontaneous mutants of scattered traits were found in the fertile progeny of the cross between wild rice and cultivated rice.In the self-crossing F₂ population of scattered spontaneous mutants,scattered trait and erect trait plant DNA were randomly selected to construct a pool for resequencing,respectively.Then,using recessive analysis?RCA?,SSR,InDel and other molecular markers,the scattered gene LAZY3 was finely mapped by RCA.The results are listed as follows:?1?Statistical analysis of phenotypic characteristics and agronomic traits.Tiller angle of upright trait plants is close to zero degree,and tiller angle of scattered plants is close to 30 degree.The number of tillers of upright plants is more than that of scattered plants?P<0.01?.The 100 grain weight of the upright plants is significantly lower than that of the scattered plants?P<0.01?.The total grain weight is significantly higher than that of the scattered plants?P<0.01?.The upright plants have no significant difference in spike length compared with the scattered plants.?2?Preliminary mapping.In the F₂ population,a mixed pool for scattered populations and upright population,respectively was constructed by randomly selecting equal amounts of DNA from 50 scattered plants and 50 upright plants,respectively.The scattered population mixed pool and the upright population mixed pool were resequenced respectively.A total of 44.45 Gbp clean bases sequencing data was obtained,respectively with Q30 reaching 80%.The average sequencing depth of each sample was 59.35 X.Employing SNP loci with different genotypes between the two mixed pools,using the Euclidean Distance?ED?algorithm to perform target site association analysis,a peak appeared on chromosome 8.According to the association threshold,a total of 1 candidate region related to scattered traits was obtained,with a total length of 7.84 Mb.InDel with genotype differences between the two pools was used for target site association analysis,and a peak appeared on chromosome 8.According to the determination of association threshold,a total of 1 candidate regions related to scattered traits was obtained,with a total length of 7.79 Mb.By intersecting the results of the associated regions corresponding to SNP and InDel,a candidate region with a total length of 7.78 Mb was obtained to be associated to scattered traits.Therefore,the LAZY3 was initially located in a 7.78 Mb interval on chromosome 8.?3?Fine mapping.Polymorphic SSR and InDel molecular markers between scattered trait plants and erect trait plants are developed in the associated region on chromosome 8.By using the inbred population of homozygous scattered trait and the homozygous erect trait,the rice scattered gene LAZY3 was located a 10 Kb interval between molecular markers XS51 and XS52 using BSA-RCA analysis.