Identification of meloidogyne species collected from different parts of Turkey and determination of virulence of some root-knot (Meloidogyne spp.) populations

Root-knot nematodes (Meloidogyne spp.) cause significant quality and yield losses in crops throughout the world. The objective of this study was to identify the root-knot nematode samples, by molecular and morphological means, that have been collected from different regions of Turkey. The seventy-nine root-knot nematode samples were first homogenized by inoculating susceptible tomato cultivar `Simita F1? with single egg masse.Then, second stage larvae obtained from homogenized-egg masses were used for DNA isolation. The molecular identification of the samples were conducted with species-specific SCAR (sequence characterized amplified region) and PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) markers. The morphological identification of the samples were carried out using dissected-fixed vulva of female and second stage larvae collected from susceptible tomatoes (homogenized samples). Results showed that four root-knot nematode species, M. incognita, M. arenaria, M. javanica and M. chitwoodi were the most common in Turkey. Of the 79 samples, 22 (28 %), 21 (27 %), 28 (35 %), and 8 (10 %) were identified to be M. incognita, M. arenaria, M. javanica and M. chitwoodi, respectively. This is the first report for M. chitwoodi in Turkey. All the samples that were collected from potato crop in mid-anatolia belong to M. chitwoodi. The distribution of Meloidogyne species by region and crop offers important insight for Turkish agriculture. 8, 13 and 7 populations of M. incognita, M. arenaria and M. javanica were used in this study respectively. Result showed that none of these populations belonging to three different root-knot nematode species were able to overcome the resistance controlled by single dominant gene Mi in tomato, indicating that populations were not virulent.