Molecular Characterizatin
of the Most Important Species and Races
of the Root-Knot Nematode (Meloidogyne spp.)

Root-knot nematodes are considered as major pests all over the world. Meloidogyne spp. are one of the ten most important ones. Out of 40 described species of Meloidogyne only 4 cause 95% losses and they are highly distributed with very wide host range. These common spp. are M. incognita, M. juvanica, M. arenaria, M. houpla. The first three species are tropical Meloidogyne spp. and cause more than 100 million Egyptian pounds in field and vegetable crops according to FAO estimation 1981. The control of root-knot nematodes specially by the recent ways as crop rotation and resistant plants require accurate identification of these species and their races.

OBJECTIVES

•  Collection of Meloidogyne spp. isolates from Egypt.

• Identification of the Meloidogyne isolates originated from different areas in Egypt by using the traditional methods:
a. Perineal pattern: to identify the cultures to the species level.
b. Differential hosts: to identify the preidentified cultures by using the perineal pattern to the race-level.

•  Using RAPD-PCR technique to differentiate between the Meloidogyne spp. cultures.

•  Comparison between the Egyptian isolates and other isolates originated from different origins traditionally and by using RAPD-PCR.

ACHIEVEMENTS

•  Collection of 50 isolates from 6 Egyptian governorates.

•  Identification of these isolates by using:
- perineal pattern
- differential hosts

•  RAPD-PCR technique used to differentiate between 32 isolates, 26 from Egypt and 6 from the States. These reactions have been done by using decamer primers from Operon Company from different kits as follows:

1. OP-Kit A 2- OP-Kit B
3. OP-Kit C 4- OP-Kit D
5. OP-Kit E 6- OP-Kit G

•  Comparison between the Egyptian isolates and the American isolates.