Detection of Molecular Markers Linked To Bread Wheat Take-All Disease (Gaeumannomyces Graminis Var. Tritici) T-41 Isolation

     Take-all is one of the most important diseases of wheat in wet areas, causing significant damage in these areas, and there has not introduced any resistant varieties against this disease until now. Therefore, efforts to identify the resistance genes to this disease and developing resistant varieties or cultivars with lower susceptible in bread wheat have a great importance.In this research, in order to identify the markers related to resistance to a isolate of take-all (T-41), a population of F2 derived from crosses of susceptible genotypes (1546 and 164) with resistant genotype (1528) and bulk segregate analysis (BSA) where used. After planting the F2 population and parents in the greenhouse and artificial infection the plants with the fungus, the plant phenotype was determined according to the amount of contamination by scoring. After DNA extraction of parents and F2 population, two bulk of DNA was prepared from resistant and susceptible individuals based on disease scores. The bulks and parental DNAs where analyzed by RAPD, SCoT, ISSR and SSR primers and PCR reaction. Among the primers are used, only one ISSR primer produced a band of 400 bp in the resistant parent and bulk which was not found in the susceptible parent and bulk. Then, all individuals of bulks and F2 where genotyped for this marker and regression and chi-square analysis showed a significant relationship between this marker and the disease score. The regrsion of disease score on band 400bp (b = -0.709) indicates that this band is more abundant in low scores (resistant individuals). Also, the distribution of F2 individuals in one of the crosses confirmed the existence of the epistatic (9sensetive: 6 semi sensitive: 1resistance) relationship