Molecular Markers Of Novel Powdery Mildew Resistance And Stripe Rust Resistance Genes In Wheat Line 101-3

Wheat powdery mildew and yellow rust caused by Erysiphe graminis f.sp.tritici . and caused by puccinia striiformis Westend, f.sp.tritici. respectively, are two important foliar disease of wheat and important fungal diseases of wheat in many regions in the world . A novel dominant powdery mildew resistance gene and a dominant stripe rust resistance gene, temporarily named PmX and Yr101-3,respectively, in a new wheat line 101-3 derived from the progeny of the cross between common wheat and Dsypyrum villosum Candery L. was located on chromosome 6B and 1B by monosomic analyses.In the present study, SSR promers mapped in the chromosome 6B and 6A of common wheat were used for PCR amplification using the genomic DNA of resistant and susceptible bulks between 101-3 and Chinese Spring and their parents to tag the powdery mildew resistance gene in line 101-3. No polymorphic products were observed in most primers. However, one primer Xgwm570 , amplified polymorphic among resistant and susceptible bulks and their parents. The primer Xgwm570 was then used to amplify DNA of the F₂ population from the cross 101-3/Chinese Spring. The result indicate that primer Xgwm 570 was linked to the resistance gene PmX with the genetic distance 9.72cM suggested that the PmX might be located in the chromosome 6BL of common. There are amplified sites in 6AL and 6BL and using Xgwm570 as primer the result of monosomic analysis indicatied that the resistance gene of prowery mildew was located on 6B.104 SSR markers distributed on the chromosome 1B were chosen for screening for polymorphisms between the parents and two bulks, Two markers WMC419 and WMC216 were polymorphic between the two bulks and two parents. Primer pair WMC419 revealed 2 polymorphic fragments between the two bulks and two parents, with sizes of 145bp and 115bp in Chinese Spring and 165bp and 145bp in 101-3. WMC216 amplified fragment with size of 135bp in Chinese Spring and 125bp in 101-3.These two microsatellite markers showed 1:2:1 segregation in the 128 F₂ population from the between Chinese Spring and 101-3, These results indicated that the two microsatellites are co-dominant markers genetic distances of 8.2cM and 5.8cM. Based on the origin and molecular markers of stripe rust gene in line 101-3 might be a new gene for stripe rust resistance.