ABSTRACT With the spread of pine wilt disease (PWD) caused by pinewood nematode (PWN), Bursaphelenchus xylophilus , its prevention and control have posed significant challenges for forestry environmental management worldwide. To mitigate the adverse effects of chemical control methods, this study focused on the inherent properties of pine trees themselves. Pinus thunbergii Parl. with different susceptibility to PWD (susceptible pines in Fushan Forest Park, PF, and resistant pines in Qingdao University campus, PQ), along with Cedrus deodara (Roxb.) G. Don (CD), Platycladus orientalis (L.) Franco (PO) and Pinus massoniana Lamb. (PM), were selected as experimental materials. Bioassay of PWN inoculation on branch segments from different coniferous plants indicated that the PWN number was largest in PM, next in sequence were PF, CD, PQ and PO, which showed that P. massoniana were most susceptible to PWN. GC–MS analysis revealed distinct chemical compositions amongst these species, abietic acid, palmitic acid, squalene, longifolene and α‐pinene were components with the most obvious difference. Longifolene and α‐pinene demonstrated effective nematicidal properties at low concentrations, aligning with the observed resistance patterns of the tested plants. Trans ‐squalene, uniquely present in CD and PO exhibited strong nematicidal activity, which conformed to the resistance of these two species. Abietic acid, found in higher concentrations in PM and PF , was found to be PWN attractant, potentially contributing to susceptibility of plant hosts to PWN. In contrast, palmitic acid showed the least impact on PWN. Overall, this study explores the relationship between the chemical profiles of coniferous plants and their resistance to PWD, with the goal of offering information for breeding PWD‐resistant pine trees.
Zhao et al. (Sun,) studied this question.