No abstract

X12 was a new race of soybean cyst nematode (SCN) with super strong pathogenicity and it was first detected in Xingjiashe county, Gujiao city, Shanxi province, China in 2012, which was a huge threat to soybean production. The research of race X12 distribution is meaningful for developing management strategies to prevent race X12 population from spreading. Therefore, a survey for the distribution of soybean cyst nematode race X12 in Gujiao city was conducted in 2019 and 2020. A distribution of races was constructed based on Riggs model. The race distribution was discussed in this study. A total of 33 soil samples infected soybean cyst nematode were collected. Twenty-six were identified as physiological subtypes, accounting for 78.8% of the samples, in which race 2 and race 4 accounted for 57.7% (15 samples) and 42.3% (11 samples), respectively. In general, race X12 was determined if race 4 population virulent on ZDD2315 accession with female index (FI) > 10. In 11 samples determined as race 4, including two samples were further determined as race X12 including the sample collected from Xingjiashe location, which was