Resistance to broomrape species (Orobanche spp.) in common vetch (Vicia sativa L.)

Common vetch (Vicia sativa) is widely used as green manure, pasture, silage, hay and for grain for livestock feed. Its major areas of cultivation coincide with areas of heavy infestation by broomrapes, mainly Orobanche crenata, but also Orobanche aegyptiaca and Orobanche foetida.We report resistance against O. crenata in V. sativa observed in the field, and characterised for selected resistant accessions both in pots and mini-rhizotrons against several Orobanche species. All species studied formed tubercles on common vetch although in varying densities depending on the species and the accessions. However a significant proportion of these became necrotic and died, with frequencies varying with Orobanche species and V. sativa accessions. The cultivar Mezquita is more resistant than PI-183723 against the two populations of O. crenata studied, and also against O. aegyptiaca. However the mechanistic basis of the resistance of Mezquita seems to differ with the Orobanche species. Its resistance against O. crenata is based on retarded development of established tubercles, whereas resistance against O. aegyptiaca is active earlier reducing tubercle formation.