First record of Xiphinema hunaniense Wang & Wu, 1992 (Dorylaimida: Longidoridae) associated with tea (Camellia sinensis (L.) Kuntze) in Thanh Hoa, Vietnam

The dagger nematodes, Xiphinema spp., are migratory root-ectoparasitic nematodes that cause damage to a wide range of wild and cultivated plants over the world. In Vietnam, this nematode group has been studied mainly based on morphological characterizations. During a survey of pathogens associated with tea, a plant with many medicinal and therapeutic potentials, a population of Xiphinema hunaniense was recorded. This study provides the first morphological and molecular characterizations of Xiphinema hunaniense found on Tea in Vietnam. The 28S rDNA, and 18S rDNA phylogenetic trees of the genus Xiphinema are also provided. 18S rDNA sequence of X. hunaniense is also submitted to GenBank for the first time.

Ectoparasitic nematodes: emerging challenges to wine grape production in the Pacific Northwest of North America.

Plant parasitic nematodes are a constraint to the production of wine grapes worldwide. In the Pacific Northwest (PNW) of North America, including British Columbia (BC) in Canada and Oregon (OR) and Washington (WA) in the United States, the impact of plant parasitic nematodes, specifically ectoparasitic nematodes, on wine grape production has not been extensively studied or documented. This chapter discusses the economic importance, geographical distribution, host range, damage symptoms, biology and life cycle, interactions with other nematodes and pathogens, and recommended integrated management of Mesocriconema xenoplax and Xiphinema americanum infesting grapes in North America. Future research requirements and future developments are also mentioned.

Molecular phylogenetic analysis and comparative morphology reveals the diversity and distribution of needle nematodes of the genus Longidorus (Dorylaimida: Longidoridae) from Spain

The genus Longidorus constitutes a large group of approximately 170 species of plant-ectoparasitic nematodes that are polyphagous and distributed almost worldwide. Some of the species of this genus are vectors of plant viruses. Species discrimination in Longidorus is difficult because the morphology is very conservative, and morphometric characters often overlap, leading to potential misidentification. Integrative taxonomy, based on the combination of molecular analyses with morphology, is a useful and necessary approach in Longidorus species identification. In Spain from 2014 to 2017, we conducted nematode surveys among cultivated and wild plants, from which we identified 13 populations of Longidorus, two of which appeared to represent new species and are described herein as L. iliturgiensis sp. nov. and L. pacensis sp. nov., and 11 populations belonging to eight known species: L. africanus, L. baeticus, L. carpetanensis, L. fasciatus, L. nevesi, L. cf. olegi, L. pini, and L. vallensis. Three species are new geographical records for Spain (L. nevesi, L. cf. olegi, and L. africanus). We report molecular data for L. nevesi, L. cf. olegi, L. carpetanensis and L. pini for the first time. Additionally, we describe the males of L. pini and the juveniles of L. cf. olegi.

Phylogenetic relationships of Cacopaurus pestis Thorne, 1943 within representatives of the Tylenchulidae Skarbilovich, 1947 as inferred from ITS and D2-D3 expansion segments of 28S-rRNA sequences

Summary The Persian sessile nematode (Cacopaurus pestis) and pin nematodes (Paratylenchus spp.) are sedentary ectoparasitic nematodes associated with many plant species worldwide. In this study, we provide morphological and molecular characterisation of seven populations of C. pestis and eight species of Paratylenchus recovered from north-western Iran. A total of 26 new sequences of D2-D3 expansion segments of 28S rRNA and ITS rRNA were obtained and used to reconstruct phylogenetic trees. Results of phylogenetic analyses revealed that the subfamilies of Tylenchulidae form well-separated clades, but that the genera Cacopaurus and Paratylenchus (= Gracilacus) in the subfamily Paratylenchinae are clustered in one clade. It appears that the previously used character of “stylet length greater than 40 μm” is not homologous and evolved more than once within the Paratylenchinae.