Morphological, enzymatic and molecular characterization of root-knot nematodes parasitizing vegetable crops

ABSTRACT Species of the genus Meloidogyne are limiting factors in vegetable crop production. Studies in Brazil about the occurrence of root-knot nematodes in areas of vegetable crop growth have been conducted without using advanced techniques. Using modern techniques, such as biochemical and molecular methods, improves the accuracy of Meloidogyne species identification. The present study characterized species of Meloidogyne in 36 samples associated with vegetable crops using isoenzyme electrophoresis, SCAR markers, and morphological markers, in addition to validating SCAR markers for accurate species identification. The species M. incognita, M. javanica, M. hapla, M. morocciensis, and M. arenaria were identified, with the first two being the most frequent. Here, the species M. arenaria parasitizing scarlet eggplant and M. morocciensis parasitizing pumpkin and cabbage are reported in Brazil for the first time. Esterase electrophoresis efficiently separated the species of Meloidogyne found in vegetable crops; however, SCAR markers were only effective for the identification of M. incognita, M. javanica, and M. hapla, since the primer pair Far/Rar yielded no amplification product to confirm the identity of M. arenaria. The species M.arenaria and M. morocciensis could not be distinguished by the female perineal patterns. Based on the present results, new primers should be designed for the identification of M. arenaria and M. morocciensis.