Abstract:

A primary study on effects of benzoic acid (BA) on pine wilt disease caused by pine wood nematode (Bursaphelenchus xylophilus, PWN) was carried out in the laboratory. Twigs of Pinus massoniana were cultured in different concentration of BA solution. It is showed that lower concentration of BA solution extended survival time of twigs significantly. Although brown stain appeared on some leaves of twigs cultured in higher concentration, these twigs survived as long as the control. Symptom caused by BA was different from that of pine wilt disease. Pine twigs inoculated with PWN were cultured in 1.0 mmol·L^-1 BA solution and tap water, respectively. The results showed that both transpiration intensity and survival time of twigs cultured in BA solution were significantly more than those of twigs cultured in tap water, and development of wilt of these twigs was significantly slower, although PWN in twigs cultured in BA solution increased as normally as nematodes in twigs cultured in tap water. It was suggested that BA in diseased trees had inhibitive effects on this disease by inhibiting pathogenic microbes which was involving in this disease or improving vitality and anti-disease ability of pine tree.

Key words: benzoic acid, Bursaphelenchus xylophilus, pathogenic toxin, plant disease control