Species variability of Pinus elliottii, P. elliottii×P. caribaea, and P. massoniana in response to pinewood nematode infection

Pine wilt disease (PWD), caused by Bursaphelenchus xylophilus, poses a severe threat to global pine forests. This study evaluated the susceptibility of one-year-old seedlings of three pine species—Pinus massoniana, P. elliottii × P. caribaea, and P. elliottii—to PWD through artificial inoculation. Results showed that all species were generally susceptible at the seedling stage, developing symptoms and experiencing high mortality within a short period. However, P. elliottii, native to North America, exhibited the highest resistance, with slower disease progression and reduced pinewood nematode spread. P. elliottii × P. caribaea showed intermediate susceptibility, while the native P. massoniana was the most vulnerable, with rapid symptom onset and extensive xylem damage. These findings provide insights into species-specific resistance and inform breeding strategies for PWD management.