First Report of the Root-Knot Nematode Meloidogyne kralli in Switzerland.

Abstract

The root-knot nematode Meloidogyne kralli Jepson was originally described from Carex acuta L. near the Elva River in Estonia (3). This species, which was rarely detected in Russia, Poland, and the UK, was observed on Cyperaceae hosts in very wet, sandy, peat, and silt soils (1). Although marked as a rare and unusual root-knot nematode, a wider European distribution was hypothesized, particularly for natural habitats where Cyperaceae are common (4). In October 2001, we finished the first root-knot nematode survey in Switzerland, which included a protected peat-moss area named Hüttensee near Wädenswil at 660 m altitude. Small smooth galls were observed on the roots of different Carex species. These galls contained several hatched second-stage juveniles, partly swollen juveniles, and a few swollen adult females with small egg masses. No protruding egg masses were observed outside the galls and no males were observed inside. Second-stage juveniles together with males also were isolated from adhering soil. The identification of these nematodes as M. kralli was based on female and second-stage juvenile morphology, and female malate dehydrogenase and esterase isozyme phenotypes (2,4). M. kralli is the only root-knot nematode known to parasitize Cyperaceae hosts, although this nematode has other monocotyledonous hosts, such as Hordeum vulgare L. (1). To our knowledge this is the first published report of M. kralli from the Alps.