| Stripe rust, caused by Puccinia striiformis f.sp. tritici, is one of the most serious diseasesof wheat in the worldwide, and planting resistant cultivars is the most effective andeconomical methods to control this disease. But one cultivar "loses"its resistance in severalyears because of resistant gene single and overcomed easy by pathogen. HTR(High-temprature Resistance) is a sort of excellent resistance to contrilloling stripe rust and itis durable resistance. So, for controlling stripe rust, identifying new resistance genes andstudying the molecular basis of HTR is of importance. Consequently, the research describedin this thesis focused on the above two aspects. 1. Identification and molecular mapping of YrHua, a new stripe rust resistance gene Ptathyrostachys huashanica Keng is a special species and distributed in Huashanbranches of the Qinling moutain chain, which is resistance to all stripe rust races in China.Crossing triticum aessivum 7182 with P. huashanica, a translocation to be attained and namedit H9020-17-5. H9020-17-5 is resistance to stripe rust, too. It suggests that the resistance genein H9020-17-5 comes from Ptathyrostachys huashanica Keng through inoculatingPtathyrostachys huashanica Keng, 7182 and H9020-17-5 with stripe rust races CY30, CY31,CY32. To mapping the resistance gene, H9020-17-5, Mingxian169, BC1 and F2 progeny(which were developed by set dialed crossing between H9020-17-5 and Mingxian169), wereevaluated for resistance in the seedling stage to Chinese P.s. tritici races under controlledtemperature in the green house, and it suggests that H9020-17-5 control stripe rust resistanceby single gene whatever it is male or female. Named it YrHua. Genomic DNA was extractedfrom 119 F2 plants and used for cosegregation analysis. 166 SSR markers and 81 AFLPmarkers were used to identify molecular markers for this resistance gene. Analysis of variance,as well as simple and composite interval mapping, were applied. The map were constructedAbstract 5detecting this gene 28.7cM to the wheat microsatellite (WMS or SSR) marker Xgwm169,which on the long arm of chromosome 6A, and 5.4cM and 2.7cM to the AFLP markersPM14(301)and PM42(247), respectively. For the convenience of marker-assisted selection inwheat breeding, one of the two AFLP markers was converted to PCR marker using a pair ofspecial primers designed based on the DNA sequence of PM14(301) and the polymorphism ofrestriction site. Our research results provided a useful tool for marker-assisted selection andyet laid the foundation of the fine mapping and map based cloning YrHua gene.2. Identification and analyse different expression genes involved in Xiaoyan6-Puccinia striiformis f.sp. tritici incompatible interaction under high-temprature In order to understand the molecular basis of resistance responses to stripe rust in wheatHTR, cDNA-AFLP (cDNA amplified fragment length polymorphism) analysis was used toidentify differentially expressed transcripts during the Xiaoyan6-Puccinia striiformis f.sp.tritici incompatible interaction under high-temprature. In the research, threerestriction-enzymes including MseI and two isocaudarnes (EcoRI and MunI) were used, andthe highly virulent race CY30 was selected as the experimental system. According to result of our laboratory, finding very few different fragments betweeninoculated and non-inoculated seedings before nesrotic lesions were observed. Therefore, thedifferently expressed genes after nesrotic lesions were observed in this research.Approximately 2700 TDFs (transtript-derived fragments) were screened, and found 22up-regulated or induced expression TDFs. Of these fragments, five were found to behomologous to previously characterized genes based on Blast analysis, and some of theirdifferential expression patterns were further verified using semi-quantitative RT-PCR. TDF6-2 encoded a gene which is homologous with a gene from Vibrio vulnificus,...
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