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.

Molecular Characterization of Root-Knot Nematodes Meloidogyne spp. Isolated from Cucumber Farms in Different Iraqi Regions

“…In contrast,Rashidifard et al (2019) observed that only 3% of South African samples were attributed to the M. hapla species. A prior study in Brazil byBarros et al (2018), encompassing 36 soil samples and vegetable roots with galls, revealed that the least common species were M. arenaria (11.1%) and M. hapla (8.3%).M. arenaria was identi ed at its lowest proportion in the Ghanaia region of Wasit City, accounting for only 1.06% of all species collected, corroborating the ndings of a previous study.…”

Evaluation of the Efficiency of some Nanoparticles and Chemical Nematicides in Controlling Root-Knot Nematodes Meloidogyne Incognita (on Eggplant)

“…Due to the small size of these galls, the large number of species of more than 110 species, and the similarity of a large number of their species to morphological characteristics, overlapping signs and morphometric measurements, which increased the difficulty of diagnosing them for more than one method, including diagnosis using genetic fingerprinting, chemical method and morphological method. The oldest and most widely used methods depend on anatomical differences, including body length, female shape, spear shape, perineal pattern planning in the back of the mature female body and others (Barros et al, 2018) and (Cunha et al, 2018). In order to reduce the damage of these galls to below the level of economic damage, various means were used to combat them, including chemical methods, which proved successful despite the fact that they cause pollution to the environment in addition to killing beneficial organisms in the soil.…”

Interaction of Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 Race 3 with Meloidogyne javanica (Treub, 1885) Chitwood, 1949 Race 3 in Tomato and Pepper

“…Vegetable varieties are being infected by more than one Meloidogyne species at once (Barros et al 2018) causing damage on plant together. Because the feeding sites are similar, two or more coexisting Meloidogyne species may interact and probably pressure the population density of other species.…”