The Genes Mapping Of Regulating Flag Leaf Posture And Cell Biology Analysis In Wheat

High yield of wheat and photosynthesis rate are closely related with the flag leaves, and the products of photosynthesis of flag leaves are the main resource of grain filling. Therefore, it is important to regulate the posture of flag leaves for improving the yield of wheat.Wheat is one of the most important crops in the world; however, the genetic control of flag leaf posture is not understood well.Therefore, identifying QTLs/genes regulating flag leaf posture can help wheat breeders to develop wheat varieties with desirable plant architecture. This research firstly used a recombinant inbred line (RIL) population and a F₂ population derived from two Chinese winter wheat varieties Xiaoyan 54 and 8602 to map genes regulating the flag leag posture The relationship between droopy leaf and dead cells of pulvinus with Evan's blue was also studied. The main results were as follows:1. The"Xiaoyan54×8602"RIL population exhibited significant differences in flag leaf posture. Ten SSR/gene markers were detected to linke with the flag leaf posture in 2D chromosome, inclduing Xwmc144,Xcfd233,Xbarc228,Xwmc41,Xwmc181,Xcfd16,Xcfd168,gs2,Xgwm539,Xcfd161.2. After screening more than 7000 F₂ plants of"Xiaoyan54×8602", we identified 700 F₂ plants with typical droopy or erect flag leaves. By genotyping these plants with the associated SSR markers, we found that Xwmc144 marker linked closely with the erect flag leaves, and most of the F₂ plants with droopy flag leaves conferred erect allelesat this locu. This result indicated that the droopy flag allele was dominant over the erect allele at this locus.. Xbarc1138 was closely linked with the droopy flag leaves and the genotypes of erect ones were mostly same to that of droopy ones except a few heterozygous genotypes. This result indicated that the erect flag allele was dominant over the droopy allele at this locus The erect gene was locted 0.8 cM proximal to the marker Xwmc144, on the short arm of chromosome 2D, and the droopy gene was locted 3.3 cM distal to the marker Xbarc1138 on the long arm of chromosome 2D. Both of these locus closely linked with the centromere of chromosome 2D.3. We found some dead cells in pulvinus of droopy flag leaves, so the relationship between droopy leaf and dead cells of pulvinus with Evan's blue was studied. The results suggested that the drooping flag leaves were not closely related with dead cells of pulvinus from the degree of coloration between droopings and erectness.