Greenhouse and field resistance in cucumber to root-knot nematodes

Ten cultigens were evaluated for resistance to Meloidogyne arenaria races 1 and 2, and M. javanica under greenhouse and field conditions. Resistance t o M. arenaria races 1 and 2, and M. javanica was verified in Cucumis sativu s var. hardwickii line LJ 90430 and to M. arenaria race 2 in C. sativus var . sativus Southern Pickler and Mincu in a greenhouse test. Another cultigen of C. sativus vat. hardwickii (PI 215589) was found to be resistant to M. arenaria race 2 but not to other root-knot nematode species tested. LJ 9043 0 is the cultigen of choice to develop root-knot nematode resistant cucumbe rs, since it has multiple root-knot nematode resistance and is cross-compat ible with cucumber. Greenhouse and field data were positively correlated (r = 0.74) over both years. Experiment repeatabilities were calculated from t he cultigens infected with root-knot nematodes under both greenhouse and fi eld conditions. Four environments (greenhouse and field over 2 years) were used in the analysis. Repeatabilities were high in all instances (ranging f rom 0.83-0.99) and indicated that the environment (field or greenhouse) was not an important factor in assessing root-knot nematode resistance for the cultigens evaluated.