Investigation and Infection Source Analysis of Root Knot Nematode Disease of Panax notoginseng in Lancang County, Yunnan Province

PurposeIn order to provide reference for comprehensive prevention of root-knot nematodes disease, the present study investigated and identified the pathogen species and sources of root-knot nematodes in the understory plantation and nursery in Lancang County of Yunnan Province.

MethodThe systematic investigation method was used to investigate the occurrence of Panax notoginseng and weeds root-knot nematodes disease and identify the pathogenic nematodes of the P. notoginseng and the weeds which under the same habitats in the understory plantation and nursery in Lancang County.

Result Among the three bases, the root-knot nematode of Datangzi nursery base was the most harmful, with an incidence rate as high as 66.82%; followed by the forest base, while the Haguoma nursery base was relatively light. After collection and identification, the pathogenic root-knot nematodes that endangered P. notoginseng and weeds in the forest base and nursery bases were Meloidogyne hapla. There are 97 species of weeds distributed under the Pinus kesiya var. langbianensis forest, among which two weeds with root-knot nematode disease include Ageratina adenophora and Centella asiatica. According to the distribution abundance of weeds and the parasitic degree of root knot nematode, A. adenophora is the main intermediate host of root knot nematode of P. notoginseng. The types of weeds in the two nursery bases are basically the same, with 124 species of weeds distributed, among which 11 weeds with root-knot nematode disease include Rabdosia serra, A. adenophora, Bidens pilosa, Laggera alata, Cassia nomame, Crassocephalum crepidioides, Elsholtzia ciliata, Emilia sonchifolia, Anemone rivularis and Siegesbeckia orientalis. According to the distribution abundance of weeds and the parasitic degree of root knot nematode, B. pilosa, C. crepidioides and A. adenophora are the main intermediate host of root knot nematode of P. notoginseng.

ConclusionThe pathogenic nematodes which infected P. notoginseng and weeds in the understory plantation and nursery in Lancang County were confirmed as M. hapla. The disease of seedlings is the main reason for the occurrence of root knot nematode of P. notoginseng in the forest, and the pathogenic nematode in the soil of nursery comes from the enrichment of susceptible weeds. Therefore, the selection of Sanqi nursery grounds, the removal of weeds during nursery and transplanting are the key to disease prevention and control.