Pathogenicity of Various Bursaphelenchus Species to Pines and Implications to European Forests : Sustainability of Pine Forests in Relation to Pine Wilt and Decline

1999

S. 14-22

Bandaufführung

55100

Bursaphelenchus xylophilus (not present in Europe) poses a risk to European forests. Isolated reports indicate that B. mucronatus, endemic in Europe and Asia, might also be pathogenic. During a survey for the presence of Bursaphelenchus species in conifers in Austria, Germany, Greece and Italy and in wood imported from Siberia, B. mucronatus was found to be the most abundant species in Central Europe and Siberia, whereas B. sexdentati was the most abundant in South Europe. Both species showed pathogenicity in inoculation tests with 3-year-old pines in climate chambers and outdoors, while b. hofmanni (Central Europe), B. hellenicus (Greece), B. tusciae (Italy) and B. leoni (South Africa) did not. 9 out of 16 B. mucronatus provenances and 3 out of 4 B. sexdentati isolates caused at least 70% mortality in Pinus sylvestris and P. pinaster / P. nigra irrigated with 200 ml water per pot per week in a climate chamber at 25°C and outdoors. The highest mortality rate was observed in Greece. 1 out of 2 "avirulent" B. xylophilus isolates was pathogenic to P. sylvestris. Large numbers of nematodes were reisolated were reisolated from affected plants. It cannot be excluded that some Bursaphelenchus species might be involved in pine decline in some European regions.