| The molecular marker, which was established in the early of 1980s, is a DNA sequence-based genetic marker system. It was now widely used in many research fields, such as genetic map constructing, gene mapping and cloning, marker assistant selection and comparative genomics researches. In present study, different types of molecular markers (SSR, EST, RGA etc.) were used to map the stripe rust resistance gene Yr26 and develop the chromosome-specific markers for chromosome 1R of Secale cereale, 1Rk#1 of Roegneria kamoji , 1V and 6VS of Haynaldia villosa.1. Development of markers for wheat stripe rust resistance gene Yr26Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most devastating wheat diseases worldwide. Development of resistant cultivars is the most economic, effective and ecological approach to control the disease. However, most of the cultivars with genes for resistance to stripe rust have lost resistance because of the co-evolution of host resistance and pathogen virulence. T. aestivum-H, villosa 6VS/6AL translocation lines were highly resistant to stripe rust with resistance gene Yr26 located on chromosome 1B. In order to better utilize Yr26 in wheat improvement, we attempted to develop SSR and EST-based STS markers more closely linked with Yr26. 35 SSR markers and 81 STS markers derived from EST sequences located on chromosome1B were select to analyse resistant and susceptible bulks as well as their parents. The results showed that 5 pairs of SSR primers, GWM11,GWM18,GWM413,BARC181and WMC419, and 8 pairs of STS primers, WE173,WE171,WE177,WE201,WE202,WE210,WE11and WE17, could amplify polymorphic fragments between resistant and susceptible bulks and their parents. These thirteen markers were used to amplify the DNA of individuals in Yangmai 5/92R137 F2 population. Most of the susceptible plants amplified the bands as same as that from susceptible parent and most resistance plants amplified the bands as same as that from resistant parents or both. Using Mapmaker 3.0b, the linkage between Yr26 and the 13 markers was detected with genetic distances ranging from 1.4 to 14.1 cM. Among them, nine markers, WE173,WE171,WE177,WE201,WE202,WE210,Xgwm11,Xgwm18 and WEll, showed the genetic distances less 5.5 cM with the Yr26, especially WE173 with genetic distance of 1.4 cM.Using Chinese Spring nulli-tetrasomic, telosomic and deletion lines, the polymorphic markers flanking Yr26, WE173 and Xwmc419, were physically mapped in the long arm of chromosome 1B, and the markers close to Yr26, WE173 and WE201, were mapped in deletion bin 1BL-6. Therefore, gene Yr26 was mapped in deletion bin 1BL-6 near the centromere of chromosome lB.Eight cultivars and advanced lines developed by different institutes used 6VS/6AL translocation lines as resistant parents, were identified using selected markers closely linked to Yr26. Five of them, Nei 2938, Neimai 9, Nei 4221, 95-108 and Nannong 9918, could amplify the specific linked markers, while three derivatives, Shi01Z056, A4-74-8 and A5-82-3-5, can not amplify the markers. The result of molecular assisted selection was in agreement with the result by race inoculation test in the greenhouses. The markers linked to Yr26 developed in this study should be efficient tools for identifying Yr26 in the breeding program.2. Development of markers specific to chromosome 6VS of Haynaldia villosaThe resistance gene of powdery mildew Pm21 was introduced from Haynaldia villosa into common wheat and located on 6VS. In order to precisely map and clone Pm21, more molecular markers and chromosome structural variants need to be developed. 11 RGA and 17 pairs of STS primers were selected to screen polymorphism between wheat-Haynaldia villosa 6VS/6AL translocation and Yangmai 5. One RGA primer and a pair of STS primer amplified polymorphic fragments, about 1000bp and 800bp, respectively. Two pairs of primers, CINAU17 and CINAU18, were designed according to the sequences of two polymorphic fragments. The results indicated that CINAU17-(1086) and CINAU18-(723) were located on chromosome 6VS because only the materials with 6VS could amplify the specific fragments. Furthermore, CINAU17-(1086) was located in the region of 6VS between FL0.58 and FL0.70, and CINAU18-(723) was located in the region between FL0.45 and centromere by using 6VS deletion addition lines and translocation lines. The results obtained by using these two markers were coincided with that by using cytogenetic identification in the structural variants of chromosome 6VS induced by radiating powder. Therefore, CINAU17-1086 and CINAU18-723 markers could be used to rapidly detect the correspondent chromosome segments of 6V and the breakage points of deletion lines.3. Development of chromosome-specific markers for chromosome 1R of Secale cereale, 1V of Haynaldia villosa and 1Rk#1 of Roegneria kamojiIn order to develop chromosome-specific markers for chromosome 1R of Secale cereale, 1V of Haynaldia villosa and 1Rk#1 of Roegneria kamoji, 104 STS primers were designed based on EST sequences distributed on chromosome 1A, 1B and 1D of Triticum aestivum. Five STS markers, CINAU 19-500,CINAU20-950,CINAU21-1500,CINAU22-310 and CINAU23-2000 amplified from S.cereal, T. aestivum-S, cereale amphiploid and 1R addition line, but not from CS and 2R-7R addition lines, were specific to 1R of S. cereale. Five STS markers, CINAU23-1700,CINAU24-1050,CINAU25-1650,CINAU26-500 and CINAU27-620 were specific to 1V of H. villosa because of the corresponding fragments amplified only from H. villosa, T. durum-H, villosa amphiploid and 1V addition line, not from CS and 2V-7V addition lines. And five STS markers, CINAU27-960,CINAU28-1360,CINAU29-480,CINAU30-560 and CINAU31-520 specific to 1Rk#1 of R. kamoji were screened owing to specific fragments amplified from R. kamoji, Wheat-R. kamoji DA1Rk#1 and DS1Rk#1(1A). The result indicated that STS markers derived from the EST of common wheat were useful tool for identify corresponding specific chromosomes of wheat relatives.
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