Molecular Marker Of Powdery Mildew Resistance Gene Pm723in A Stable Wheat Line Derived From The Hybrid Progeny Of Wheat—Thinopyrum Intermedium

Powdery mildew caused by Erysiphe graminis f.sp. tritici is one of the important wheat diseases worldwide which influences and limits wheat stable and high yield,. The loss of resistance for cultivars resulting in the variance of diseases in wheat growing area was usually because wheat powdery mildew with a high degree of pathogenic variability. In addition, it was also important factors for the powdery mildew resistance was lost due to the emergence of new advantages disease races, the improvement of cultivation level and the extensive application of cultivated varieties with single resistance gene. Therefore, there is very important significance to lasting discover and research new resistance genes, and obtain varieties with new resistance gene to control wheat powdery mildew.In recent years, the rapid development of molecular biology techniques provides a more rapid and accurate and effective way for detecting resistance genes in different materials at the molecular level. In order to study and accelerate the use of powdery mildew resistance gene Pm723in a wheat stable line723derived from the hybrid progeny of wheat-Thinopyrum intermedium, the powdery mildew resistance genes in wheat line723were analyzed and SSR molecular marker screened by using BSA and SSR molecular markers in present study. The main results were list as follows:1. Genetic analysis of powdery mildew disease resistance in line723in adult plant stages indicated that the wheat line723and its F1population of723×Miangyang26(MY26, a cultivar which is seriously susceptible powdery mildew and stripe rust) were immune to powdery mildew, and the segregation ratio for resistant and susceptible plants of F2population showed good fit into3:1, which suggested that there is a single dominant resistance gene responsible for the powdery mildew resistance in line723, and temporal named Pm723.2. DNA polymorphism analysis of disease-resistant pool and susceptible pool using SSR molecular markers was carried out. No polymorphisms were found when the165pairs of SSR primers located on the chromosome6B were amplified between the resistant pool and susceptible pool. Polymorphic fragments were observed when the primers Xcfd22and Xgwm314of the remaining658pairs SSR primers amplified among parents, resistant-susceptible bulks and partial of F2individuals. The polymorphic SSR primers were used for F2populations. There were2and4of145F2plants have changed for Xcfd22and Xgwm314respectively. Linkage analysis and draw genetic linkage map by conducted with the software JoinMap4.0. The results indicated that the Xcfd22and Xgwm314markers were linked to Pm723with the respectively genetic distance of1.4cM and2.8cM, and the sequence of loci was Pm723-Xcfd22-Xgwm314. Two markers were linked to Pm723but located on the same side. It could effectively trace and detect Pm723in wheat background.3. The primer Xcfd22has amplification site on4BL,7BL,1AL and1BL of common wheat, while the primer Xgwm314can be amplified on4BL and3DL of common wheat. Based on the genetic analysis of two markers, we can deduce that Pm723locates on4BL of wheat.4. Comparison with the reported powdery mildew resistance genes, Pm723might be a new powdery mildew resistance gene, but its source is not sure, therefore, further research should be carried out in future.