Morphological and Molecular Characterization of a New Record of Paratylenchus straeleni (Nematoda: Paratylenchidae) from Forest Soil in Göttingen, Germany

Paratylenchus spp. are obligate ectoparasitic roundworms that are distributed worldwide. Despite multiple studies reporting the occurrence of Paratylenchus species in German agricultural fields, morphological and molecular data on these species remain scarce. A recent study aimed to bridge this knowledge gap by providing detailed morphological, morphometric, and molecular data on the pin nematode Paratylenchus sp. in Germany. Soil samples were randomly collected from ten different localities within Stadtwald Göttingen for nematode extraction. Among the sampled sites, Paratylenchus sp. populations were detected at only one location. Specimens from this site were selected for identification using an integrative taxonomical approach, combining morphological and molecular characterizations. Morphologically, the nematodes were identified as Paratylenchus straeleni , characterized by a long stylet (ranging from 54.5 to 61.0 µm), the lateral field with four incisures, and the presence of advulval flaps. To confirm species identity, DNA amplification was performed using specific primers targeting the 18S rRNA gene, D2-D3 region of 28S rRNA, the internal transcribed spacer region (ITS1-5.8S-ITS2), and the cytochrome c oxidase subunit I (COI) gene. BLAST analysis and phylogenetic reconstructions based on these markers consistently confirmed the species as P. straeleni , with strong support indicated by high posterior probability values (≥ 0.99). To the best of our knowledge, this is the first report of P. straeleni occurring in Göttingen, Germany. This finding highlights the need for further investigation, particularly regarding the species' distribution and its potential phytosanitary and ecological implications.