A novel species-specific satellite DNA family in the invasive root-knot nematode Meloidogyne mayaguensis and its potential use for diagnostics Onivaldo Randig & Florence Deau & Marcilene F. A. dos Santos & Myrian S. Tigano & Regina M. D. G. Carneiro & Philippe Castagnone-Sereno Received: 28 January 2009 / Accepted: 28 May 2009 / Published online: 21 June 2009 # KNPV 2009 Abstract The root-knot nematode (RKN) Meloido- gyne mayaguensis is considered as one of the most damaging RKN species because of its extremely wide host range. Recent surveys have shown the rapid spread of this parasite in agro-ecosytems, often making crop cultivation not viable in the heavily infested areas. Here, we report the identification, molecular cloning, genomic organisation and se- quence analysis of a new satellite DNA (satDNA) family from M. mayaguensis (named pMmPet). It is comprised of two groups of A+T rich, tandemly repeated units of 174 and 180 bp, respectively. Using these sequences as targets, hybridisation and PCR experiments performed on a wide collection of 44 populations belonging to 15 RKN species showed that the pMmPet family could only be detected in the 16 M. mayaguensis populations tested. In addition, because of their repetitive nature, positive detection of pMmPet sequences was achieved in single individual nematodes. Therefore, the repeated sequence described here possesses features that make it an excellent candidate for use as a specific and extremely sensitive tool for the accurate detection and identification of this invasive pest on a routine basis. Clearly, monitoring the occurrence and spread of M. mayaguensis at the domestic and international levels are needed to avoid wholesale loss of agricultural resources in the infested regions. Keywords Bioinvasion . Diagnostics . Genetic marker . Root-knot nematode . Satellite DNA Introduction The root-knot nematode (RKN) Meloidogyne maya- guensis was originally described in 1988 from speci- mens obtained from galled roots of eggplant from Puerto Rico (Rammah and Hirschmann 1988). Because of its wide host range, including crops carrying genes that confer resistance to the main Meloidogyne species (Brito et al. 2007), this species is considered as one of the most damaging RKNs. Early reports highlighted the presence and economic importance of this parasite in West Africa (Fargette et al. 1996). In 2000, the geographic distribution of M. mayaguensis was restricted to Africa, Central and South America, and the Caribbean (CAB International 2000). More recently, it was reported in Brazil (Carneiro et al. 2001) and in Eur J Plant Pathol (2009) 125:485–495 DOI 10.1007/s10658-009-9497-0 O. Randig : M. F. A. dos Santos : M. S. Tigano : R. M. D. G. Carneiro EMBRAPA – Recursos Genéticos e Biotecnologia, C.P. 02372, 70849-970 Brasília, DF, Brazil F. Deau : P. Castagnone-Sereno (*) INRA UMR1301, UNSA, CNRS UMR6243, Interactions Biotiques et Santé Végétale, 400 route des Chappes, BP167, 06903 Sophia Antipolis, France e-mail: Philippe.Castagnone@sophia.inra.fr