Distribution of the pinewood nematode in China and susceptibility of some Chinese and exotic pines to the nematode

Abstract

From 1983 to 1987 a survey was made to determine the hosts and geographic distribution of the pinewood nematode Bursaphelenchusxylophilus (Steiner and Buhrer), the cause of pine wilt disease, in China. Samples (669) were obtained from dead and dying conifers in 18 provinces and in the federally administrated cities of Beijing and Shanghai. The nematode was only found in samples from Pinusthunbergii and P. massoniana in and around the cities of Nanjing and Zhenjiang (both in Jiansu Province). To determine the susceptibility of Chinese and exotic pines to the pinewood nematode, 15 pine species were inoculated with a Chinese isolate. The 2- to 5-year-old trees, growing at Qingdao (Shandong Province) and Hongjiang (Hunan Province), were inoculated in mid-August to mid-October 1985. The results showed that one pine (P. bungeana) was extremely susceptible to the pinewood nematode, seven were highly susceptible (P. yunnanensis, P. densiflora, P. armandii, P. kwangtungensis, P. elliottii, P. koraiensis, and P. thunbergii), four were moderately susceptible (P. taiwanensis, P. griffithii, P. fenzeliana, and P. sylvestris var. mongolica), and three were resistant (P. taeda, P. massoniana, and P. banksiana). The results are discussed in relation to the needs for quarantine and management of pine wilt disease in the People's Republic of China.