DIVERSITY AND COMMUNITY ANALYSES OF SOIL NEMATODES ASSOCIATED WITH GUAVA FROM WEST BENGAL, INDIA

Survey on plant and soil nematodes associated with rhizosphere of guava (Psidium guajava L.) from Baruipur, 24-Paraganas(south) and Mondouri (Haringhata) and Ghoragachha (Chakdaha), Nadia, West Bengal, India revealed the occurrence of ten genera, viz. Meloidogyne, Pratylenchus, Hoplolaimus, Rotylenchulus, Helicotylenchus, Tylenchorhynchus, Criconemoides, Xiphinema, Longidorus and Aphelenchus. Altogether thirteen species of eight plant parasitic genera identified which were Meloidogyne incognita, M. javanica, M. graminicola, Pratylenchus coffeae, P. brachyurus, Hoplolaimus indicus, Rotylenchulus reniformis, Helicotylenchus goodi, H. indicus, H. abunamai, Tylenchorhynchus mashhoodi, T. nudus and Aphelenchus avenae. The estimation of population density from rhizospheric soil indicated more number of R. reniformis (1052/200cm 3 soil) and Helicotylenchus (233/200cm 3 soil). Community analyses of plant and soil nematodes from the guava rhizosphere further revealed that R. reniformis ranked first in prominence followed by Helicotylenchus and Tylenchorhynchus. Among the less prominent plant parasitic species present as in guava rhizosphere, Pratylenchus, Meloidogyne, R. reniformis, Xiphinema and Longidorus were the potential pathogens to cause decline of yield either alone or in association with soil pathogens. Some ectoparasitic nematodes genera were also prominent members of soil nematode community but less important as plant pathogens. Among sapropzoic nematodes, rhabditids, dorylaimids and diplogasterids are the most prominent members of soil nematode community diversity and primarily play significant role in ecosystem processes of soil for making availability of plant nutrients.