QTL Mapping For Ear Length And Three Ear-leaves Length Traits Of Maize

Ear length and leaf length are important plant type traits and ear traits in maize.The genetic research of these two traits is of great significance for improving maize yield and breeding ideal plant type,which will provide theoretical basis for breeding excellent maize varieties with high yield and density tolerance.In this study,a pair of high generation Sister Lines with significant difference in ear length and leaf length were used as parents:female parent L1?ear length and leaf length?,male parent L2?ear length and leaf length?to construct F₂ segregation population and F_2:3 family.Using SPSS software and segregation analysis software to analyze the phenotype of each population,and analyze the genetic law of ear length and three ear-leaves length.Linkage markers of panicle length and Trifolium length were screened by BSA method,and related QTLs were mined and their effects were analyzed.The results are as follows:?1?The results showed that there were significant differences in ear length and grain number per row between parents,and there were significant differences in leaf length,branch number of tassel and leaf angle between parents.There was no significant difference in other agronomic traits between parents.?2?In this study,we measured the phenotypes of F₂ segregating population,F_2:3families'ear length and three ear-leaves length.The results showed that the ear length and three ear-leaves length of the two populations presented Gaussian distribution,and the ear length and three ear-leaves length were in accordance with the major gene+polygene model controlled by two pairs of genes.The heritability of major gene of ear length was 49.0%and28.5%,polygenic heritability was 25.6%and 10.8%;heritability of major gene in under ear leaf was 41.5%and 36.2%,polygenic heritability was 31.7%and 24.4%;heritability of major gene in ear leaf was 47.39%and 37%,polygenic heritability was 37.6%and 27.0%;heritability of major gene in above ear leaf was 67.68%and 68.25%,polygenic heritability was 13.0%0%and 12.8%.?3?The linkage markers of ear length and three ear-leaves length were detected on chromosome 6 by BSA extreme pool screening.The genetic linkage map of chromosome 6was constructed by using F₂ segregation population,and QTL was mapped by combining the traits of panicle length and clavater leaf length in F₂ population and F_2:3 families.The QTLs of ear length and above leaf length were mapped between bnlg1867-umc1229,LOD thresholds were 6.49 and 5.95,with 12.82%and 11.90%phenotypic contribution rate.QTLs of under ear leaf and ear leaf were located between umc1229-umc2314,LOD thresholds were4.78 and 6.61,and phenotypic contribution rates were 9.80%and 13.41%.