Genetic diversity of Moroccan populations of Orobanche foetida: evolving from parasitising wild hosts to crop plants M C VAZ PATTO*, R DI ´ AZ-RUIZ  , Z SATOVIC à , B ROMA ´ N§, A J PUJADAS-SALVA ` – & D RUBIALES** *Plant Cell Biotechnology Lab, Instituto de Tecnologia Quı´mica e Biolo ´gica, Universidade Nova de Lisboa, Oeiras, Portugal,  Colegio de Postgraduados, Campus Puebla, Puebla, Mexico; àDepartment of Seed Science and Technology, Faculty of Agriculture, University of Zagreb, Zagreb, Croatia, §Departamento de Mejora y Agronomı´a, CIFA ÔAlameda del ObispoÕ, IFAPA, Co ´rdoba, Spain, –Departamento de Ciencias y Recursos Agrı´colas y Forestales, UCO-ETSIAM, Co ´rdoba, Spain, and **Instituto de Agricultura Sostenible, CSIC, Co ´rdoba, Spain Received 13 July 2007 Revised version accepted 21 November 2007 Summary Orobanche foetida is widely distributed in western Mediterranean countries infecting wild legumes. Recently it has been reported in Morocco infecting common vetch, presenting a further constraint for legume production in this area. Comparative studies between Orobanche populations attacking wild species and Orobanche populations growing on crops from the same region may help to clarify whether a host special- isation process occurred. In the present study, the genetic variability of five O. foetida populations, four infecting wild plants and one infecting cultivated vetch in Morocco was characterised using amplified fragment- length polymorphism (AFLP) markers to elucidate the existing genetic relationship between populations and to suggest a potential origin for the recently detected vetch- infecting population. Analysis of molecular variance suggested the existence of genotypic differentiation among populations. The most genetic divergent popu- lation by cluster analysis was the population collected on Ornithopus sativus. The vetch-infecting O. foetida population was closer to the three populations infecting Scorpiurus muricatus. The possibility of the presence of a reservoir of diversity is balanced against direct genetic adaptation and completely new introduction. The potential for this Orobanche species to shift host and become a threat to agriculture exists and has to be taken into account for future legume breeding for these areas. Keywords: broomrape, genetic variability, Morocco, host specialisation, parasitic plant. VAZ PATTO MC, DI ´ AZ-RUIZ R, SATOVIC Z, ROMA ´ N B, PUJADAS-SALVA ` AJ & RUBIALES D (2008). Genetic diversity of Moroccan populations of Orobanche foetida: evolving from parasitising wild hosts to crop plants. Weed Research 48, 179–186. Introduction Orobanche (broomrape) are holoparasite species, entirely lacking in photosynthetic function, parasitising plant roots, withdrawing water, mineral nutrients and metabolites through a specialised structure, the hausto- rium (Parker & Riches, 1993). Over 20 Orobanche species have been described as weeds throughout the world, some of them, such as Orobanche ramosa L. [syn. Phelipanche ramosa (L.) Pomel], Orobanche cumana Wallr., Orobanche aegyptiaca Pers. [syn. Phelipanche aegyptiaca (Pers.) Pomel] or Orobanche crenata Forsk., being major weeds in Asian, European and African countries, with tremendous economic impact (Rubiales et al., 2006; Joel et al., 2007). Orobanche foetida Poir. is an annual or perennial plant species belonging to the section Orobanche Grex Cruentae Beck, together with Orobanche gracilis Sm., Orobanche crinita Viv. and Orobanche variegata Wallr. Orobanche foetida is present in the Mediterranean area strictly in the western Mediterranean countries – Morocco, Algeria, Tunisia, Portugal and Spain (Pujadas-Salva` et al., 2003). Correspondence: M C Vaz Patto, Instituto de Tecnologia Quı´mica e Biolo´gica, Universidade Nova de Lisboa, Plant Cell Biotechnology Lab, Apt. 127, 2781-901 Oeiras, Portugal. Tel: (+351) 214 469461; Fax: (+351) 214 411277; E-mail: cpatto@itqb.unl.pt Ó 2008 The Authors Journal Compilation Ó 2008 European Weed Research Society Weed Research 48, 179–186