Evaluation On Density-tolerant Characteristics Of Maize Inbred Lines And Association Analysis Between SNP And Density-tolerance

High yield is the main target of maize breeding,breeding density-tolerant maize varieties,depending population yield on increasing per plant yield is the inevitable trend and direction of higher yield of maize.As maize inbred line is the basis breeding material,study the problem of density-tolerant has become hot point.In this research,238 maize inbred lines were used as materials,and set 2 planting densities,75000 plants/hm2 and 135000 plants/hm2.Study agronomic traits of inbred line in different density,selecting the density-tolerant evaluation traits and establishing the evaluation system of maize inbred line high density-tolerant,combines association analysis to find the corresponding SNP markers.Research results as follows:1.Analyzing indexes of coefficient of variation in two density,selected three evaluation traits of maize inbred line high density-tolerant: per plant yield,ear insertion difference and ASI difference.2.Evaluation system of per plant yield,ear insertion difference,ASI difference as evaluation traits of maize inbred line density-tolerant were established.According to evaluation system,we selected 10 density-tolerant materials,including B283-1,LiangyuS122,Danhuang212,D25-2-1-1-1,pr07007-1,pr07438-2-2-1,SN7135,Y32-1-1-1-1-1,Huangzaosi,L201.3.The SNP whose –Log(p)value was higher(GLM model)and genetic typing was good was considered to be more important.15 key SNPs associated with per plant yield,located on chromosome 2,3,4,5,6,7 and 8.26 key SNPs associated with ear insertion difference,located on chromosome 1,4,7 and 10.13 key SNPs associated with ASI difference,located on chromosome 1,4 and 8.According to MLM model,8 key SNPs associated with per plant yield,located on chromosome 1,3,4,5 and 9.13 key SNPs associated with ear insertion difference,located on chromosome 1,4,7 and 10.12 key SNPs associated with ASI difference,located on chromosome 1,4 and 8.Under these models,4 SNPs associated with per plant yield,13 SNPs associated with ear insertion difference,12 SNPs associated with ASI difference.