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Specific Diagnosis of Two Root-Knot Nematodes, Meloidogyne chitwoodi and M. fallax, with Satellite DNA Probes

May 1999 , Volume 89 , Number  5
Pages  380 - 384

P. Castagnone-Sereno , F. Leroy , M. Bongiovanni , C. Zijlstra , and P. Abad

First, second, third, and fifth authors: INRA, Unité Santé Végétale et Environnement, BP 2078, 06606 Antibes Cedex, France; and fourth author: IPO-DLO, Research Institute for Plant Protection, 6700 GW Wageningen, the Netherlands

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Accepted for publication 28 January 1999.

Meloidogyne chitwoodi and M. fallax are serious pests of potato, and both species have been recently designated as quarantine organisms in the European Community and in Canada. The sympatric and less damaging species M. hapla is often found associated with both of them under temperate climates. Here, we describe the use of satellite DNA (satDNA) sequences previously isolated from these three root-knot nematode species for the development of specific diagnostic procedures. In dot-blot experiments, it was unambiguously possible to separate M. chitwoodi and M. fallax from M. hapla using satDNA monomers as probes. In squash-blot experiments, satDNAs allowed discrimination between single individuals of M. chitwoodi or M. fallax from M. hapla, even within root tissues, without the need for DNA purification. The same results were obtained with radioactive or digoxigenin-labeled probes with no loss of sensitivity in detection. M. fallax and M. chitwoodi could not be distinguished. From this study, it is concluded that such cloned satDNA sequences may constitute a powerful tool for the identification and management of Meloidogyne spp. populations in the field and for the implementation of quarantine regulations against these pests.

Additional keywords: species-specific probe, squash-blot procedure, tandem repeats.

© 1999 The American Phytopathological Society