Analysis QTL And Agronomy Traits And Genetic Diversity Of Drought Tolerance In Maize

Maize is one of the most important crops, which it is of strategic importance for the development of national economy to stabilize maize production in China. It is a global problem to absent water resource, especially, to use it in agriculture. Drought can cause significant yield reductions in maize and it is one of the most important factors influencing maize yield. Most important traits are controlled by micro-effect and most genes in maize, such as yield, quality and resistant. Flowering, plant height and ear height are relation with yield and these traits will affect yields directly in maize. Understanding of genetic diversity and relationships among germplasm resources in maize are based on breeding. Understanding of genetic diversity among inbred lines can help to assign parent and genetic variety and predict hybrid advantages, which it is the key of breeding object. The results are as follows:1. Analysis F_2:3 families derived from the cross A188 x 91 Huang 15 using 430 SSR (simple sequence repeats) primer pairs. The genetic linkage map with 133 marker loci was constructed based on maize (Zea mays). The map covered 2646 cM on 10 chromosomes with an average interval length of 19.89 cM.2. Understanding quantitative trait loci (QTL) for plant height and ear height, the results showed that under normal conditions 2 and 4 QTL associated with plant height and ear height in 2003, which could explain 48.6% and 12.5% of phenotypic variation, respectively. Under drought conditions 4 and 6 QTL associated with plant height and ear height, respectively. Each QTL could explain over 7.5%²0.7% of phenotypic variation. The QTL located on chromosome 8 on arm (8.02-8.05 bins) accounted for nearly half of total QTL detected, with LOD more than 4.8. It was postulated that chromosome 8 carries important regions controlling plant height and ear height. In 2004, under normal conditions 4 and 2 QTL associated with plant height and ear height, which could explain 48.6% and 72.5% of phenotypic variation, respectively. Under drought conditions 6 and 4 QTL associated with plant height and ear height, respectively. Each QTL could...