Abstract:Potato (Solanum tuberosum L.) is the third most important food crop in Yunnan province, China. 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-spectra Rpi genes using molecular markers and evaluation of late blight resistance upon field inoculation were conduced in 255 potato genotypes. The results showed that 69, 53, 51, 12, 23 and 75 varieties (lines) were detected with resistance genes R8, RB, Rpi-blb2, Rpi-sto1, Rpi-sto1 and Rpi-vnt1.1, respectively. Eighty-one of the varieties (lines) were found stacking multiple Rpi genes, and 77 of them were collected from CIP. Gained from field resistance tests, 67, 31, 67 and 90 varieties (lines) were observed with high resistance, medium resistance, medium sensitivity and high sensitivity, respectively. The domestic germplasm was found with lower resistance and rare cases on stacking multiple Rpi genes. The gene R8 largely contributed to the field resistance against late blight. R8 via stacking with other Rpi genes can improve the degree of resistance compliance and field resistance. This study demonstrated that R8 has a high degree of compatibility with field resistance to late blight and could be used for marker assisted selection, which has implication for the future popularization and application of new varieties (lines) and resistance breeding in Yunnan province.