Growth and decline of arboreal fungi that prey on Bursaphelenchus xylophilus and their predation rate

Abstract

Pine wilt disease caused by pine wood nematodes is a deadly disease of the genus Pinus requiring strong quarantine measures. Since its discovery, it has been widely distributed throughout the world. China is one of the countries with a severe rate of infections due to its abundant pine resources. In this study, nematode-trapping fungi were collected from pine trees in Ninghai City, Zhejiang Province, which is the key area of pine wilt control in February, May, September, October and November. The results showed that nematode- trapping fungi of pine are abundant, especially the number and species detected in each month and are quite different; species of fungi in July, September and November were more numerous and had higher separation rates. The dominant species in November was Arthrobotrys oligospora followed by Arthrobotrys cladodes; July and September it was A. cladodes. In each part of the tree, A. cladodes was the most widely distributed with a high separation rate. Therefore, it is the dominant fungal species in the area. Arboreal Bursaphelenchus xylophilus-trapping fungi are dependent on pine wood nematodes, and none were isolated from healthy pine trees. More arboreal B. xylophilus-trapping fungi were found under the bark than in the xylem. There is a close relationship between arboreal B. xylophilus-trapping fungi and pine wood nematodes. How to make use of these resources to reduce the damage of pine wood nematode fusarium is the focus of future research.