First Report of Root-Knot Nematode Meloidogyne enterolobii on Tomato and Cucumber in Switzerlan

摘要

Severe stunting and extensive root galling were observed on tomato rootstock (Solatium lycopersicum L. cv. Maxifort) resistant to Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949, M. javanica (Treub, 1885), and M. arenaria (Neal, 1889) Chitwood, 1949 and cucumber (Cucumis sativus L. cv. Loustik) from two commercial greenhouses in the cantons Aargau and Lucerne in northern Switzerland. Examination of the roots of infected plants revealed the presence of root-knot nematodes in large numbers. Juveniles, males, and females were isolated, and the species was determined on the basis of morphological characteristics, including the female perineal pattern. Identification was confirmed by female esterase (Est) and malate dehydrogenase (MdH) electrophoresis (20 each for Est and MdH). All methods of identification were consistent with M. enterolobii Yang & Eisenback, 1983 (4). For further confirmation, type material of M. enterolobii (from the original host Entemlobium contortisiliquum (Vell.) Morong) from China (4) was used. Furthermore, comparison of the sequence data from 12 individuals of each of the two Swiss populations and the type material of a 310-bp fragment of cyto-chrome oxidase I (COI), a 723-bp fragment covering the internal transcribed spacer (ITS) region 1, 5.8s, ITS2, and part of the 26s, the mtDNA 63-bp repeat region, and a 780-bp fragment of the intergenic spacer region (1-3) showed 100% homology and confirmed the identification as M. enterolobii. The species M. enterolobii is of great importance because it is able to reproduce on resistant tobacco, pepper, watermelon, and tomato (4). To our knowledge, this is the first report of M. enterolobii in Switzerland.