Influence of Hosts on Morphology and Morphometry of Meloidogyne incognita

Studies were conducted at Department of Nematology, Assam Agricultural University during 2015 to observe the influence of host plants on morphology and morphometry of Meloidogyne incognita. Single egg mass population of M. incognita reared in tomato was inoculated to five different plants viz., tobacco, castor, tea, citrus and neem. No nematode infestation was recorded in neem plants, while development of female was inhibited in citrus. Morphological characters indicated that hyaline tail terminus of second sage juvenile (J₂), size of the female and perennial pattern of female was influenced by the host plants. There was a small and short hyaline tail terminus in J₂ of castor, while smaller female was observed in castor and tea population. Variation in perennial pattern with faint broken lateral lines was observed in tobacco population. Most of the morphometric characters like lip width, ‘a’, ‘b´’ and ‘c’ of J₂, and, body width and neck length of female were variable characters, while body length, stylet length, ‘b’ ratio and MB of J₂ (C.V. 2.27–10.54%), and body length, stylet length, LMB and WMB of mature female were observed as stable characters (C.V. 3.08–11.09%). Perineal pattern was found as stable with C.V. 2.83–10.8 per cent.