Grape plants (Vitis vinifera L.), like other major horticultural crops, suffer from attacks by plant pathogenic nematodes. These parasites are a serious burden for viticulturists all over the world and lead to reduced vine vigour and crop yield. The major nematode parasites infesting grapevines include Meloidogyne spp., Pratylenchus spp., Criconemella spp., Tylenchulus spp., Helicotylenchus spp., Heterodera spp. etc. Besides these genera, some nematode genera like Xiphinema, Paralongidorus and Longidorus are known to transmit viral diseases in grapevines, as they act as vectors to many viruses e.g. grapevine fanleaf virus. These pathogenic nematodes are becoming an important element affecting vine health, vigour and productivity. The present paper provides a brief overview of the diversity of phytoparasitic nematodes parasitizing vineyards, some viruses transmitted to grapevines via these parasitic nematodes and also outlines the management practices like crop rotation, hot water treatment, use of biological agents as well as use of organic amendments in controlling phytoparasitic nematodes in general.

An associated microbiome of any host helps it in different metabolic processes ranging from the decomposition of food to the maturation of gametes. Organisms with a parasitic mode of life, though present at nutritious sites inside their host, maintain their own microbiome. Nevertheless, the comprehensive characterization and functionality of microbiome in parasitic organisms remain understudied. We selected two nematode parasites of Kashmir Merino sheep viz; Haemonchus contortus and Trichuris ovis based on their higher prevalence, difference in mode of nutrition, habitation site and effect on host. The objective of the study was to explore the bacteria associated with these parasitic nematodes of sheep. We adopted a 16S rRNA metagenomic sequencing approach to estimate and compare the bacterial communities present in these two nematode species. Nematode parasites from Kashmir Merino sheep were identified morphologically and confirmed with DNA characterization. H. contortus was dominated by phylum Proteobacteria (57%), Firmicutes (25%), Bacteroidota (15%) and Actinobacteriota (3%). Conversely, T. ovis showed Proteobacteria (78%) followed by Firmicutes (8%), Bacteroidota (8%), Actinobacteriota (1%), Fusobacteriota (1%) and other phyla (4%). This study provides a comprehensive account of the microbiome composition of H. contortus and T. ovis, both of which are highly prevalent among Kashmir Merino sheep. Additionally, T. ovis exhibited a greater bacterial diversity compared to H. contortus. Notably, these nematodes were found to harbor certain pathogenic bacteria. This study can further be carried forward in gaining insights into the complex relationship between the microbiota of a parasite and its pathogenicity, reproductive potential and host microbiome modification.