Mapping Of Quantitative Trait Loci (QTL) And Genetic Effect For Important Traits With An Elite Maize Hybrid

Maize(Zea mays L.)is one of the most important crops. High grain yield is the first breeding target pursued by breeder. However, the evaluation and genetic improvement of grain yield is very difficult with the development of molecular marker and statistical genetics, quantitative trait loci (QTL) mapping has become a basic strategy in study the genetic architecture of quantitative traits. The objective of this study an F2:3 population developed from an elite hybrid(Ye Dan 13), and to evaluate effect of population size and environments on QTL mapping was analyzed. The major results are as follows.1. A genetic linkage map containing 150 SSR markers was constructed based on an F2 population with 500 individuals. The map spanned a total of 1478.7 cM with an average interval of 10.0 cM.2. With the composite interval mapping(CIM)method,180 QTL were detected for 10 plant architectures and yield related traits based on a field mapping population consisting of 397 F2:3 families at 4 environments. And, 22 ph and 21 eh relevant QTL had been identified. For yield related traits, 1 major QTL (rn7c ) of ear row number was identified tightly linked with umc1865 on chromosome bin 7.03. Several new QTL for yield related traits were detected, such as gy7,gy9a and gy9b..3. The additive and the partial dominance effects were the main genetic basis for the ph,eh(87.0%)and the yield related traits(61.6%).The genetic by environment interations may play a role in the maize genetic basis for the ph,eh and the yield related traits.4. QTL×environment interaction (QEI) were analyzed based on mixed linear model for plant architectures and yield related traits. The sequence of the traits from high to low was grain yield﹥ear height﹥kernel number per ear﹥ear weight﹥plant height,It suggested that QEI had different effect on the different traits.5. QTL had been identifid is changes to some extent at different years, height plant,ear plant and ear row number are more stable ,major QTL had been identifid general condition, but also have an exception.