Abstract
Broomrapes (Orobanche spp.) are obligate parasites that infect roots of dicotyledoneous plants. Orobanche spp. are particularly important in southern and eastern Europe, the Middle East, and north Africa. O. crenata causes severe damage to legume crops, O. cumana threatens sunflower, O. ramosa attacks potato, tobacco, tomato, and hemp, O. aegyptiaca is severe on legumes and vegetables, and other broomrapes such as O. minor are widespread on forage legumes (3). O. foetida Poir. is considered important as an agricultural parasite of faba bean (Vicia faba) and common vetch (V. sativa) crops in the Beja Region of Tunisia (1). Aside from that, it has never been found infecting crops, even where it is widely distributed in the western Mediterranean area (Portugal, Spain, Morocco, Algeria, and Tunisia) parasitizing wild herbaceous leguminosae in the genera Anthyllis, Astragalus, Ebenus, Lotus, Medicago, Ononis, Scorpiurus, and Trifolium (2). In May 2004, we found O. foetida commonly occurring in Morocco infecting wild leguminosae. It was not seen infecting legume crops such as faba beans, chickpeas, or lentils, even where O. foetida was abundant in the close proximity to the crop fields, or in the field itself. In these instances, we verified that O. foetida was infecting weeds such as Scorpiurus spp. and not the crop plants themselves by gently pulling out the plants and examining the roots. However, O. foetida was identified infecting common vetch (V. sativa) on a small farm in Taounate, Saiss Region, 50 km north of Fes. Infection of vetch plants was confirmed by digging up the plants to verify the attachment of the broomrape plant to the vetch roots. The level of infection was moderate (0.1 to 0.2 broomrape plants per vetch plant). The farmer stated that he had observed this problem only in the last 3 years. Morphology was typical of O. foetida, i.e., dark reddish plant, 20 to 50 cm tall, corolla 12 to 20 mm, dark, purplish-red, lower lip not ciliate, filaments inserted 3 to 7 mm above base of corolla, and stigma deep yellow at anthesis (2). Voucher specimens were deposited in the Herbarium of the University of Córdoba. To our knowledge, this is the first report of O. foetida infecting common vetch and it is relevant since it indicates the first introduction of this parasite into crops in Morocco. The spread of this new crop parasite population should be monitored because it could represent a further constraint for legume production in this area. References: (1) M. Kharrat et al. FABIS Newsl. 30:46, 1992. (2) A. J. Pujadas-Salvá. Pages 187-193 in: Resistance to Orobanche: The State of the Art. Junta de Andalucía, Spain, 1999. (3) D. Rubiales. Grain Legumes 33:10, 2001.
Collapse