Pine wilt disease

Pine wilt disease (PWD) caused by Bursaphelenchus xylophilus (pinewood nematode, PWN) is a major quarantine forest disease worldwide. North America is considered to be the native of PWD, while forests in Japan, China, and Korea are most affected in Asia, and forest in Europe is also seriously threatened by PWN. Pine wilt disease develops rapidly after PWN infects pine trees, which causes great harm to the forest and serious economic losses due to the difficulty in its control. Pinewood nematode can naturally infect 47 and 14 pine and nonpine species, respectively. The disease prevalence is affected by host plant species, pinewood nematode, vector and many other environmental factors. The pinewood nematode can cause pine wilting very fast, and the pathogenic mechanism is complex and remains unclear. At present, disease prevention and control mainly rely on disease quarantine, epidemic monitoring, eradication of infected trees, vector beetle control, and injection of healthy pine trees with some nematicides. As a fundamental measure, host resistance breeding has made a good start, which will still take a long way for commercial application.