Reproduction of root-knot nematode isolates from the middle Black Sea Region of Turkey on tomato with Mi-1.2 resistance gene

Abstract

Research was conducted to evaluate the reproduction of 90 Meloidogyne isolates including Meloidogyne arenaria (Neal, 1889) Chitwood, 1949 (38 isolates), Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (4 isolates), Meloidogyne javanica (Treub, 1885) Chitwood, 1949 (11 isolates) and Meloidogyne luci Carneiro et al., 2014 (37 isolates) (Tylenchida: Meloidogynidae) from the middle Black Sea Region of Turkey on susceptible and resistant tomato cultivars in a greenhouse with temperature controlled between 2013 and 2014. Galling index and reproduction factor of nematode isolates were assessed in a pot assay and resistance-breaking isolates were determined according to their reproduction index. Among the isolates, only two isolates of M. luci (Or-2 and Pr-1) had a similar galling index on susceptible and resistant tomato (P <= 0.05). Four isolates of M. luci (cr-19, Or-2, Pr-1 and Pr-2), two isolates of M. arenaria (A-7 and Sn-11) and an isolate of M. incognita (A-11) produced more eggs than the initial inoculum on resistant tomato. These root-knot nematode isolates, except two isolates of M. arenaria, were classified as resistance-breaking isolates having a reproduction index higher than 10%. These findings showed that the Mi-1.2 gene confers resistance to M. luci but four isolates of M. luci could overcome this resistance. This is the first report for resistance-breaking isolates of M. luci in tomato.