Abstract: 【Objective】To analyze the genetic law and gene mapping of powdery mildew resistance in seed-used pumpkin in Hohhot,Inner Mongolia Autonomous Region,and provide reference for parental breeding of seed-used pumpkin resistant varieties.【Methods】13 international identified melon hosts were used to identify the physiological race of powdery mildew.Six-generation populations were constructed with powdery mildew resistant varieties M2 as the maternal parent and powdery mildew susceptible varieties F4 as the paternal parent. The genetic law of powdery mildew resistance in seed-used pumpkin were analyzed by chi-square fitness test. The resistant and susceptible pool and two parental pools were created through the F2 segregating population,and the resistant genes were initially mapped using BSA-seq and InDel molecular marker.【Results】The physiological race of powdery mildew in seed-used pumpkin was 2US;the genetic characteristics of F2 segregating population plants were normally distributed and showed quantitative traits,and powdery mildew resistant traits were controlled by a pair of single dominant genes. Seed-used pumpkin powdery mildew resistant genes were linked to three related candidate regions with a total length of 3.41 Mb and containing 468 genes. In the candidate region,the powdery mildew resistant gene of seed-used pumpkin was mapped to the tenth linkage group,and the two linkage markers were pm10-8 and pm10-1.【Conclusion】The powdery mildew resistant gene in seed-used pumpkin was located between marker pm10-8 and marker pm10-1,and the genetic distance from the two flanking markers was 20.5 cM and 17.1 cM,respectively. There were 27 candidate genes in this region.

Key words: Seed-used pumpkin, Physiological race, Genetic law analysis, BSA, Powdery mildew, Molecular marker