Abstract:Potato(Solanum tuberosum L.) is the third most important food crop in Yunnan Province. Late blight has always been a devastating disease in potato production. Use of resistant varieties is the most fundamental and effective way to control the disease. In this study, screening of broad-spectrum Rpi genes molecular marker and evaluation of late blight resistance upon field in 255 potato genotypes. The results showed that there were 69, 53, 51, 12, 23 and 76 varieties(lines) containing R8, RB, Rpi-blb2, Rpi-sto1, Rpi-sto1 and Rpi-vnt1.1, respectively. Eighty-one of the varieties(lines) were polymerized with multiple broad-spectrum Rpi gene markers, and 77 were derived from CIP. The results of field resistance identification showed that: Among the 255 varieties (lines), 68, 35, 68 and 84 varieties(lines) were of high resistance, medium resistance, medium sensitivity and high sensitivity, respectively. Thirty-three moderately resistance and 60 highly resistance varieties(lines) were derived from CIP, respectively. Compared with CIP, the domestic germplasm is lack of resistance and polymerization of multiple broad spectrum Rpi gene markers. R8 marker played a major role in field resistance to late blight, which was highly consistent with field resistance. Potato polymerized R8 markers and other broad-spectrum Rpi gene markers can improve the degree of resistance compliance and field resistance. This study demonstrated that R8 marker have a high degree of compatibility with field resistance to late blight and could be used for marker assisted selection, which could provide scientific basis for the future popularization and application of new varieties(lines) and resistance breeding in Yunnan Province.