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Potato (Solanum tuberosum L.) is the world's fourth largest food crop, plays an important role in both industrial and agricultural production in our country and the world. Potato production is constrained by a variety of pests and diseases, including late blight greatest impact. Potato late blight vertical resistance did not last long, because the the new Phytophthora infestans race will quickly overcome this single gene resistance. Multiple genes control the level of resistance is a non-species-specific, with the broad spectrum of resistance to late blight resistant potato varieties level lasting breeding levels of resistant varieties is one of the important goals of improved potato varieties. Control the level of resistance to many minor genes of pathogenic and environmental complex interactions, as well as four potato cultivars body heredity makes the choice very difficult. This study used a candidate gene strategy, level of potato late blight-resistant material B groups cited in the International Potato Center the screening late blight horizontal resistance significantly associated molecular markers for marker-assisted selection. The main findings are as follows: 1. This study were randomly selected from the horizontal resistance groups B 122 lines, physiological races with P.infestans mixed lobular vitro identification. The identification results show that the level of 122 strains of late blight vitro disease stage tends to normal distribution. 2. Potato mapping population targeted molecular markers have been reported, the selection and late blight resistance QTL tightly linked to or from the structure of the NBS-LRR marked resistance to late blight level of EST sequence specific primers were designed mark detection, the selected strains. The experimental shared 38 of the candidate gene-specific primers simple PCR amplification. Amplified with type stepwise regression analysis showed that, BA228d23 90 , grol-2-P40 500 , NL27 250 , GP23 600 , GP23 1200 , R × 1 300 , GP179 570 , prp1 800 8 Ge mark with late blight the horizontal resistance significantly related. 3. Target level of enrichment late blight resistance gene has been constructed subtractive cDNA library screening the EST, whereby specific primers were designed. Another according to the LM-PCR primer sequences specific primers. Amplification of these specific primers with corresponding random primers to be optimized for each strain of TRAP. Amplified band type ,1-1650, 1-1360 ,2-1820 ,2-1380 ,3-1500 ,3-1380 ,3-480 ,5-1670 ,5-1300 ,5-1100, 6 - 820,7-1180,7-640,8-1740,8-1360,8-260,9-420,14-1360,14-220,13-1360,13-1100,13-410 with Phytophthora infestans level anti- significantly related. 4. The analysis found that resistance to late blight level was significantly related marker-assisted selection results, multi-marker selection more efficient than single marker selection. 5. The experimental results show that, in resistance to late blight level of molecular marker-assisted selection using a candidate gene strategy can efficiently screening molecular markers associated with horizontal resistance.
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