First report of Laimaphelenchus heidelbergi (Nematoda: Aphelenchoididae) in Europe

A survey of nematodes associated with branches of cork oak, Quercus suber, a species in decline since the second half of the 20th century, was conducted on two farms located in Alentejo, Portugal. Using specific morphological characters, some nematodes were identified as belonging to the genus Laimaphelenchus and one of the isolates being identified as L. heidelbergi. This research aimed to characterize the Portuguese L. heidelbergi isolate using morphobiometrical and molecular analyses and to analyze its phylogenetic relationship to other Laimaphelenchus spp. Morphometric and morphological characteristics of L. heidelbergi females and males were similar to the original description. For molecular analyses, the mitochondrial DNA region from the cytochrome oxidase subunit I and the D2/D3 expansion segments of the large subunit of rDNA were amplified and sequenced. In phylogenetic analyses, sequences of the Portuguese L. heidelbergi isolate clustered with sequences from the Australian isolate. Laimaphelenchus heidelbergi was originally described from wood of Pinus radiata growing in Australia and is here reported for the first time in Europe and Portugal. Cork oak is a new host record for L. heidelbergi.