New observations on occurrence and distribution of Bursaphelenchus spp. (Nematoda: Aphelenchoididae) in conifers in Romania

Abstract

Six species of the genus Bursaphelenchus were recovered as the result of a survey to assess the potential introduction of Bursaphelenchus xylophilus into the conifer forests of Romania. Bursaphelenchus xylophilus was not detected in the sampling regions. Bursaphelenchus dietrichi was recovered from one point, representing the first report of this species in the country. The other detected species, B. abietinus, B. andrassyi, B. hofmanni, B. fraudulentus and B. willibaldi, were characterized by their morphometric data and molecular analyses. The morphometrics of Romanian populations of B. hofmanni and B. willibaldi are presented for the first time. The phylogenetic relationships of the recovered species (except for B. abietinus, with no successful sequencing) were reconstructed using the sequences of the D2‐D3 expansion segments of the large subunit of ribosomal DNA (D2‐D3LSU rDNA). Some of the species were also characterized using the restriction fragment length polymorphism (RFLP) pattern of the internal transcribed spacer (ITS) fragment. The distribution, related host trees and phylogenetic relationships of the identified species are discussed.