Preliminery Studies On The Molecular Markers Of Mating Type And Albino Trait And The Genes Of Interaction With Wheat In Blumeria Graminis F.sp.Tritici

An optimization strategy for RAPD fingerprinting was designed based on orthogonal test, which remarkably reduced the number of experiments. Optimum conditions for RAPD with the maximum number of score products were determined as 2.0mmol/LMgCl2, 0.1 mmol/L dNTP, 0.5umol/L primer, 5ng DNA and 1.5U Taq for Blumeria graminis f. sp. tritici. The results also showed that the concentration of primer, DNA were the main factors that effact RAPD fingerprinting.Under the optimal conditions, 520 RAPD primers and 45 randomly selected RAPD primer pairs were used to screen polymorphic bands of the mating types and the albinao trait. Twenty-four and fifteen primers or primer pairs, respectively, could amplify polymorphic DNA bands in genome DNA pool for mating type and albino trait. One primer, OPQ09 (5'-GGCTAACCGA-3') that generated a RAPD marker was found, named OPQ09685, polymorphic in albino trait in 43 F2 segregating progenies. Another primer, OPQ03 (5'-GGCTAACCG-3'), generated a 775bp fragment pldymorphic in mating type, named OPQ03775. Thirty-four isolates from areas in Beijing, Jiangsu and Sichuan were used to test prime OPQ09. The result showed that this marker separated normally. The RAPD markers were convert to SCAR markers, SCQ09p and SCQ03p. The progenies were also amplified with the pair of SCAR primers, SCQ09p. A single band (677bp) could be revealed in albino isolates and no band was in normal isolates except for recombinants, and the recombination rate is 25.6%, the genetic distance is 15.2cM based on the calculation of MAPMAKER3.0.To this day, one hundred and seventy-four genes of Blumeria graminis f. sp. hordei have been cloned. Many of them were closely correlative to the interaction genes between barley powdery mildew and its host. In this study, we designed 4 pairs of specific primers based on the sequences of 4 genes that are functional in the interaction with barley,BIG2, Cat1, CLg, gp16, and used them to amplify genome DNA of wheat powdery mildew. The result showed that only one pair of primers could amplify genome DNA efficiently. This fragment was cloned and sequenced. The result showed that it contained 669 nucleotides, encoding 172 amino acids. The nucleotide sequence comparison, by BLAST, revealed 93% homology with B. graminis f. sp. hordei Catl gene. The B. graminis f. sp. hordei Catl gene also shared considerable sequence homology with other species of fungi.