Construction Of Genetic Linkage Map And Identification Of QTLs For Important Agronomic Trait In Maize(Zea Mays L.)

Agronomic traits have significant influence on stability and adaptability in maize production. To identify and characterize the effects of quantitative trait loci (QTL) underlying maize important agronomic traits, an F2.3population from the cross between Si287and Si144were developed. QTL analysis was carried out to determine the relationship between marker genotype and the traits evaluated. The major research results were as follows:(1) A genetic linkage map containing152SSR markers was constructed, covering total maize10chromosomes. The map spanned a total of1268. lcM with an average interval of8.34cM.(2) The187F2:3lines were evaluated for21agronomic traits including plant type-related traits, flowering-related traits and yield-related traits. Utilizing data of field tests and molecular markers, composite interval mapping (CIM) method was used to idetifiy the QTL for these traits. For plant type-related traits, a total of23QTLs were identified on chromosomes1,3,4,5,6,7,8,9and10, ranging from2%to69%of the total phenotypic variation. For flowering-related traits, a total of9QTLs were detected on chromosomes2,3and8, ranging from2%to38%of the total phenotypic variation. For yield-related traits, a total of37QTLs were detected on all chromosomes except for9and10, ranging from2%to38%of the total phenotypic variation.(3) Additive and partial dominance effect played a important role in genetic basis of plant type-related traits, flowering-related traits and yield-related traits, which accounted for80%,89%and70.2%, respectively.The results in this study will facilitate fine mapping of main QTL underlying maize important agronomic traits as well as marker-assisted selection in maize breeding program.