Studies on Resistance of Pine Species and Masson Pine Provenances to Bursaphelenchus xylophilus and the Epidemic Law of the Nematode in Nanjing

This paper deals with the studies on the resistance and resistant evaluation of the pine species: Pinus thunbergii ,P.massoniana,P.densiflora,P.taeda L., P.elliottii,P.rigida,P.echinata Mill, P.rigida var. seriotina and other 40 provenances of Masson pine,and the epidemic law of pine wood nematode(PWN),and their control treatment. The results showed that:1.There are three species of pine(P.taeda,P.echinata,P.rigida),five provenances and 3～14 year old nature stand of Masson pine resistanting to PWN;2.The first year′s high temperature resulted in the early emergence of the vector of adult Monochamus alternatus and the more rainfall limited the beetle adults′ flying and their spread,and the more concentration of their occurrence in the following year;3.The spread of the PWN has the form of point emergence immigrated from far distance,and the fact that the artificial spread along the railroad and main highway is serious,then it become widespread in the whole forest;4.Stresses should be placed on the selecting of high resistant species and provenances of pine,planting mixed forest,cutting clearly each one of the dead trees caused by PWN and fumigating them with the fumigant,and strengthening the work of quarantine.