Scholarly Journal of Agricultural Science Vol. 3(11), pp. 497-505 November, 2013 Available online at http:// www.scholarly-journals.com/SJAS ISSN 2276-7118 © 2013 Scholarly-Journals Full Length Research Paper Geographical distribution of nematodes associated with fresh water plants in Khyber-Pakhtunkhwa Jabbar Khan 1* , Muzammel Ahmed Khan 1 , Rehana Gul 1 , Sajid Ali 2 and Muzammel Ahmed 3 1 Department of Biological Sciences, Gomal University, Dera Ismail Khan Khyber-Pakhtoon-khwa, Pakistan 2 Department of Biological Sciences, Gomal University, Dera Ismail Khan Khyber-Pakhtoon-khwa, Pakistan. 3 Gomal Centre of Biochemistry and Biotechnology, Gomal University, D.I. Khan Accepted 27 October, 2013 Nematodes are elongated, multi-cellular, pseudo-coelomic, bilaterally symmetrical invertebrates. Most nematodes live hidden in soil or in plants. Most are plant parasitic. Few have obvious direct effects on humans or their activities. Here we investigated whether or not plant parasitic nematodes exist in the geographically varied areas of Khyber-Pakhtunkhwa. For this, five different localities; Dergai, Warsak, Dera Ismail Division, agriculture research institute Tarnab and Peshawar University of Khyber- Pakhtunkhwa province, were surveyed. Root samples and soil samples from around the roots of tomato, okra, maize and banana plants were collected from all the aforementioned areas. Nematodes were collected and counted from both the soil and from the roots of host plants. Interestingly, we characterized 16 species of plant parasitic nematodes, 11 of which, we reported for the first time in this region. More interestingly, we identified 4 new species, not previously reported in Pakistan. The highest number of species and nematodes as well were found in Dergai, followed by Dera Ismail Khan, Warsak and agriculture research institute Tarnab, while, in Peshawar University, no nematode was found. Key Words: Nematodes, parasite, fresh-water, free living. INTRODUCTION Nematodes are elongated tubular organisms, somewhat spindle-shaped that move like snakes. Technically, they are multicellular, pseudo-coelomic, bilaterally symmetrical invertebrates (1,2). Over 1 million kinds of nematodes are estimated, making them second only to the insects in numbers (2,3). Most nematodes live hidden in soil, under water, or in the plants or animals they parasitize; relatively few have obvious direct effects on humans or their activities (Siddiqi, 1962, Goody, 1963, Thiery et al., 1999, Swarup et al., 1968) Plant nematodes are tiny worms usually 0.25 mm to 3 mm long and cylindrical, tapering toward the head and tail. Females of a few species lose their worm shape as they mature, becoming pear-, lemon- or kidney- shaped. They are usually found in the soil around the roots of *Corresponding author. E-mail: jkhans2001@yahoo.com. fresh-water plants (Goody, 1963, Zuckerman and Richard, 1981, Bird and Bird, 1991). Some species are found within the tissues of host plants and make histo- pathological changes. Nearly all crops are attacked by plant parasitic nematodes, causing great economical loss (Siddiqi, 1962, Timm and Ameen, 1960). Among plant parasitic nematodes, root-knot nematodes are the most destructive ones (Hussey et al., 1994). Root-knot nematodes occur throughout the world. They attack more than 2000 species of plants including almost all cultivated plants (Endo and Wergin, 1988). Diseases caused by root-knot nematodes in Pakistan are very important because the climate and sandy worm soil are suitable for the development, sustenance and activities of nematodes, especially in the irrigated areas which are used for crop production. Meloidogyne incognita has been reported as a parasite of okra and tomato in Sindh region of Pakistan (Endo 1979). In Islamabad and various regions of Punjab of Pakistan, five