First Report of Root-knot Nematode, Meloidogyne graminicola on Brassica juncea in China

In southern China, the staple food rice ( ) field is commonly rotated with brown mustard . Root-knot nematodes (RKNs) are a major threat to rice production. From 2019 to 2021, in 56 fields from 26 counties in Guangxi Province were observed with symptoms of leaf yellowing, stunting, and several hook-shaped galls on the roots. Females and egg masses of sp. were found within the galls. The females, males, and second-stage juveniles (J2s) were collected, and identified with morphological and molecular characteristics and female perineal patterns. was transplanted in pots and a pathogenicity test was conducted to confirm the species as . In China, this is the first record of a natural infection of mustard with . , and this finding has great importance for Chinese mustard production, since this nematode may damage mustard plants and become an additional problem for this crop.