Agron. Sustain. Dev.
Volume 25, Number 1, January-March 2005
Page(s) 123 - 128
Agron. Sustain. Dev. 25 (2005) 123-128
DOI: 10.1051/agro:2004059

Virulence diversity among branched broomrape (O. ramosa L.) populations in France

Hocine Benharrat, Christian Boulet, Catherine Theodet and Patrick Thalouarn

Groupe de Physiologie et de Pathologie Végétales, Faculté des Sciences et des Techniques, 2 rue de la Houssinière, BP 92208, 44322 Nantes Cedex, France

(Received 30 June 2004; accepted 13 October 2004)

Abstract - In France, the obligate root parasite O. ramosa L. (broomrape) causes significant decreases in yields in several crops such as Brassica napus L., Cannabis sativa L. and Nicotiana tabacum L. Over the past few years, the broad distribution and the continuous expansion of this parasitic plant have been pointed out. The diversity of its host plants and the increase in its locations in France led us to investigate the virulence of some O. ramosa populations against their potential host plants. Significant variation in their aggressiveness was observed. These results are therefore consistent with the existence of at least two O. ramosa pathovars throughout populations scattered in France. A study by PCR of inter-simple sequence repeat (ISSR) of these two populations allowed us to characterize each of them by specific molecular markers.

Key words: broomrape / hemp / oilseed rape / virulence / pathovar

Corresponding author: Hocine Benharrat

© INRA, EDP Sciences 2005