Abstract:
Three species of the root-knot nematodes (RKNs), Meloidogyne javanica, M. incognita (races 1
and 2) and M. arenaria (race 2) were found to occur in Jordan. The species and their races were
identified using morphological characters, the North Carolina differential host test, and SCAR
based PCR assay. Cytogenetical preparations for the study of gametogenesis and chromosome
numbers were made using propionic-orcein dye for chromosome staining and Giemsa stain for
result comparison. Results indicated that the populations of M. incognita race 1, M. incognita
race 2, and M. javanica were considered hypotriploid with an average of 45.2, 46.1 and 46.7
chromosomes, respectively. The M. arenaria populations, however, were considered triploid with
an average of 52.2 chromosomes. The chromosomal numbers suggested that the mode of
reproduction for the three species was mitotic parthenogenesis |
