不同株系拟松材线虫对黄山松和黑松苗木的致病性

Pathogenicity of Different Isolates of Bursaphelenchus mucronatus to Pinus taiwanensis and P. thunbergii Seedlings

采用23个不同来源的拟松材线虫株系对2年生黄山松和2年生黑松进行人工接种试验。结果表明:1)对黄山松苗具有致病作用的拟松材线虫有4个株系,分别为CFS4,SLD3,ZJ1和KOR1。其中接种ZJ1,SLD3 2个株系的黄山松苗的死亡率均为16.7%。2)对黑松具有致病作用的拟松材线虫有9个株系,分别是CFL1,SFS1,SFS4,SLD9,SDZ1,ANL5,ANL7,AHS9和HYC1。感病指数最高的ANL5达到83.3。其次是AL7,感病指数为54.2。发病率最高的拟松材线虫株系同样是ANL5,发病率达100%。死亡率最高的拟松材线虫系是ANL5和ANL7,达50%。3)根据拟松材线虫对2年生黑松苗的感病指数、发病率、死亡率等指标,将供试的23个拟松材线虫株系划分为3个致病等级:Ⅰ级(强致病性):ANL5和ANL7个株系;Ⅱ级(弱致病性):CKL1,SFS1,SFS4,SLD9,SDZ1,AHS9和HYC1 7个株系;Ⅲ级(无致病性):ANL1,JLH1,JLH10,JXY7,JYX31,CFL4,SLD3,YWF1,GBL3,ZJ1,HN1,TW1,JAP1和KOR1 14个株系。4)来自安徽的4个拟松材线虫株系,有3个株系对2年生黑松苗具有致病作用,其中2个株系(ANL5,ANL7)具有强致病作用;来自四川的5个拟松材线虫株系,有4个株系(SFS1,SFS4,SLD9,SDZ1)对2年生黑松苗具有中等强度的致病作用,而另外1个株系(SLD3)对2年生的黄山松苗具有致病作用;来自江苏的4个拟松材线虫株系(JLH1,JLH10,JXY7,JYX3)对2年生黄山松苗、2年生黑松苗均无致病性。

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