Community Analysis of Plant Parasitic Nematodes in the Rhizosphere of Vegetable Crops in Jorhat, Assam

Abstract

The study aimed to analyze the community composition, abundance, and distribution of plant-parasitic nematodes in the rhizosphere of vegetable crops in the Jorhat district of Assam, with a focus on identifying dominant nematode species and assessing their impact on crop health. A comprehensive approach employing nematode sampling, identification, and statistical analysis to evaluate nematode population. The study was conducted in five locations (Alengmora, Teok, Jorhat, Titabar, and Mariani) of the Jorhat district, Assam, India, from 2021 to 2022. A total of 146 composite soil and root samples were collected from the rhizosphere of 39 vegetable crops. Nematodes were extracted and morphologically identified nematode species were classified into eight genera, and community metrics such as absolute frequency, relative frequency, absolute density, relative density, prominence value, and plant-parasitic index were calculated following Norton's methodology. The index of similarity was used to compare nematode communities across locations. Eight nematode species from eight genera were recorded. Meloidogyne incognita was the most dominant species, exhibiting the highest mean absolute density (5356.01) and relative density (44.51%). It also had the highest prominence value (247.25). Alengmora, Teok, and Jorhat locations harbored all eight nematode species, while Titabar and Mariani had six each. The index of similarity revealed considerable overlap in nematode species among the locations. The study highlights the dominance of M. incognita in the Jorhat district, emphasizing the need for targeted nematode management strategies. The findings offer critical insights into nematode ecology and underscore the importance of site-specific interventions to reduce crop losses in vegetable production systems.