Satellite DNA used as a species‐specific probe for identification ofBursaphelenchus xylophilus*

Abstract

The phytoparasitic nematodeBursaphelenchus xylophilusis the causal agent of pine wilt disease. However, it is difficult to differentiate isolates ofB. xylophilusfrom the closely related speciesB. mucronatus, which is not pathogenic to pine trees under field conditions. Here, we describe the development of a species‐specific DNA probe using a satellite DNA sequence fromB. xylophilus.This unusually abundant satellite DNA constitutes up to 30% of the nematode genome. It is represented as a tandemly repeatedMspI site‐containing sequence with a monomeric unit of 160 bp. We show that thisMspI satDNA probe is effective directly on a single squashedB. xylophilusnematode spotted onto a filter or by using polymerase chain reaction (PCR) amplification. Thus, in the pine wood‐nematode species complex, identification of the plant pathogenic speciesB. xylophilusmay be accomplished both rapidly and reliably.