Species of Bursaphelenchus Fuchs, 1937 (Nematoda: Parasitaphelenchidae) associated with maritime pine in Portugal

Abstract

Summary -Species of Bursaphelenchus associated with maritime pine, Pinus pinaster, from Portugal -within and outside the quarantine restricted demarcated zone of B. xylophilus -are described and characterised both morphologically (LM and SEM) and with the use of molecular biology (ITS-RFLP). A new staining method for spicules is proposed. Species include B. hellenicus, B. hylobianum, B. leoni, B. pinophilus, B. sexdentati, B. tusciae, B. teratospicularis, B. xylophilus and Bursaphelenchus sp. 1. Bursaphelenchus hylobianum was collected from the insect Hylobius sp. The most frequent species in the demarcated zone, besides B. xylophilus, was Bursaphelenchus sp. 1. Morphological characterisation is compared with the original descriptions and discussed. The differentiation between B. pinophilus and B. sexdentati is not clear in the literature and is discussed. Since differentiation of B. xylophilus (mucronate form) from B. mucronatus, and B. pinophilus from B. sexdentati, as well as their juvenile forms, is almost im possible on the basis of morphological features, a molecular approach based on ITS-RFLPs was used. Ribosomal DNA containing the 5.8S gene, the internal transcribed spacer region 1 and 2, and partial regions of 18S and 28S gene were amplified by PCR. Restriction profiles of the amplified products generated species-specific differences, leading to the unambiguous identification of isolates belonging to B. xylophilus, B. mucronatus, B. sexdentati, B. tusciae and B. hylobianum.

An inoculation experiment of JapaneseBursaphelenchusnematodes on Japanese black and red pine,Pinus thunbergiiandP. densiflora

“…For a more accurate evaluation of the potential risk of native Japanese nematodes, experiments that consider climate change by, for example, simulating drought or high temperature conditions will be necessary. Several studies have reported the isolation of Bursaphelenchus nematodes from declining pine species in Europe (e.g., Penas et al 2004;Polomski et al 2006). We believe that these kinds of risk evaluations in all regions in which native Bursaphelenchus species and related nematodes occur are necessary to develop worldwide risk management.…”

Detection of the pine wood nematode using a real-time PCR assay to target the DNA topoisomerase I gene

“…It causes rapid wilting of Pinus thunbergii and P. densiflora in East Asia and P. pinaster in Portugal Europe, which results in millions of dead pine trees every year (Mamiya 1983;Mota et al 1999;Penas et al 2004). Despite enormous impact on the pine forests, there is no efficient and environmentally friendly method available to prevent infestation.…”

Occurrence of Bursaphelenchus species in declining Pinus sylvestris in a dry Alpine valley in Switzerland

“…Whereas in northern Italy Bursaphelenchus mucronatus has also often been detected (Caroppo et al 1998), the most frequent species found in Greece were B. sexdentati and B. leoni (Michalopoulos- Skarmoutsos et al 2004). In Cyprus and in Portugal (outside the demarcated zone with B. xylophilus), the most common species was B. leoni (Braasch and Philis 2002;Penas et al 2004).…”