NEMATODES PRESENCE IN SADAT AND TAHREER AREAS WITH DETECTION OF GENETIC VARIABILITIES WITHIN ROOT KNOT NEMATODE POPULATION

摘要

Nematode is one of the most important problems in desert. Sadat and Tahreer areas are located at the North west of Egypt where nematodes survey was carried out for determining the most important nematodes genera that exist over there. Species of genrta Meloidogyne, Pratylenchus, Trichodorus, Xiphenema, Longidorus, Criconemoides, Hemicyclophora, and Tylenchorncus were found in most areas in Sadat and Tahreer, while Tylenchulus semipentrance was found only in some locations in Tahreer area. Two different molecular techniques were used to detect different species of Meloidogyne, First SCAR markers proved that only M. javanica and M. incognita existed in both areas, while M. arenaria or M. hapia were not found. When restriction enzyme (RE) Hind III wasused in RFLP test with different Meloidogyne populations, a strong band at size 560 bp and weak band at size 200 bp were observed, while bands at sizes 440 and 320 bp were obtained with Hinf I. Four bands of 220, 200, 180 and 160 bp were obtained with REDra I. These results confirm that Meloidogyne incognita is the most common type of nematodes in both areas. The RAPD markers was used to estimate the genetic relationship among different populations of root knot nematodes, so ten primers were evaluated, the genetic variabilities within different root knot M. incognita population were not significant.