Abstract:

In order to investigate the occurrence and harmful species of Gynostemma pentaphyllum root knot nematode in Ankang of Shaanxi Province, reveal the relationship between G. pentaphyllum continuous cropping and root knot nematode, and provide a theoretical basis for the control of G. pentaphyllum root knot nematode, in this experiment, G. pentaphyllum root knot nematode disease from 6 investigation sites in Ankang main producing areas was sampled and studied, and the isolation and identification were conducted by morphological observation and rDNA-ITS sequence analysis. The results showed that the root knot nematode damage was found in the main producing areas of G. pentaphyllum in Ankang, and the incidence rate in the seriously damaged plots was as high as 75.4%. Through isolation and identification, it was determined that the root knot nematode occurring on G. pentaphyllum in Ankang was Meloidogyne incognita, and the incidence increased gradually with the extension of planting years and the decrease of altitude. This is the first report of M. incognita on G. pentaphyllum in Ankang of Shaanxi Province, which could lay a foundation for further analysis of G. pentaphyllum root knot nematode population and control of the disease.

Key words: Gynostemma pentaphyllum, root knot nematode, rDNA-ITS, occurrence, Ankang, Shaanxi