Abstract:

Twenty-three strains of Bursaphelenchus mucronatus were used for inoculating two-year-old seedlings the following of Pinus taiwanensis and Pinus thunbergii to investigate their pathogenicity in this study. The main results were: 1)Four of Twenty-three B. mucronatus isolates had pathogenicity on the two-year-ole seedlings of P. taiwanensis, and they were SFS4, ZJ1, KOR1 and SLD3 respectively. 2) Nine of Twenty-three isolates of B. mucronatus had pathogenicity on the two-year-old seedlings of P. thunbergii, and they were CFL1, SFS1, SFS4, SLD9, SDZ1, ANL5, ANL7, AHS9 and HYC1 respectively. 3)According to disease index, morbidity rate and disease rate of B. mucronatus to two-year-old seedlings of P. thunbergii, twenty-three isolates of B. mucronatus were divided into three levels: Class Ⅰ (strong pathogenicity), Class Ⅱ ( weak pathogenicity) and Class Ⅲ (no pathogenicity). 4)Three of four populations from Anhui province had pathogenicity to two-year-old seedlings of P. thunbergii, wmong which two populations (ANL5 and ANL7) had strong pathogenicity; Four (SFS1,SFS4,SLD9,SDZ1) of five populations from Sichuan province had pathogenicity to two-year-old seedlings of P. thunbergii, and another population (SLD3) had pathogenicity to two-year-old seedlings of P. taiwanensis; All four populations from Jiangsu province had no pathogenicity to two-year-old seedlings of P. thunbergii and P. taiwanensis

Key words: Bursaphlenchus mucronatus, pathogenicity, Pinus taiwanensis, Pinus thunbergii