BIODIVERSITY OF PLANT PARASITIC NEMATODES OF CASHEW PLANTATIONS IN TRIPURA, INDIA

Thirteen species of plant parasitic nematodes within nine genera were isolated and identified from roots and soil around cashew nut shrubs. They were: Helicotylenchus astriatus, H. dihystera, H. elegans, Hemicriconemoides mangiferae, Hoplolaimus indicus, Meloidogyne incognita, Pratylenchus coffeae, P. brachyurus, Rotylenchulus reniformis, Scutellonema brachyurus, Tylenchorhynchus leviterminalis, Xiphinema brevicolle and X. neoamericaum. Among them, Helicotylenchus spp. (95%), Rotylenchulus reniformis (83%), Pratylenchus spp. (70%), Hoplolaimus indicus (60%), Tylenchorhynchus leviterminalis (46%) and Xiphinema spp. (28%) were the most predominant species associated with cashew nut in Tripura. All these species of phytonematodes, except Hemicriconemoides mangiferae, are new records of association with cashew nut from Tripura state as well as from India. The plantation at Belonia (10 years old) was more diverse than either the younger or older plantations when diversity was based on the numbers of nematodes. The three-years-old plantation at Nalkata was the least diverse in this regard. The twenty-years-old plantation located at Nagichherra was the most diverse when diversity was based on nematode biomass.