VARIATION IN RESISTANCE OF SOME FORAGE LEGUMES SPECIES TO OROBANCHE-CRENATA FORSK

Parasitic weeds of the family Orobanchaceae threaten many forage legumes in the Mediterranean region. Laboratory and field screening of five lines each of six forage legumes ( Vicia narbonensis L., V. sativa L., V. villosa ssp. dasycarpa (Ten.) Cavill., Lathyrus sativus L., L. ochrus (L.) D.C., and L. cicera L.) for resistance to the parasitic weed Orobanche crenata Forsk. revealed high interspecific and intraspecific variation. Lathyrus ochrus lines were free of emerged O. crenata shoots while those of L. sativus and L. cicera were highly susceptible to the parasite. Intraspecific variation in reaction to O. crenata was high within V narbonensis and V sativa, with several lines being free of Orobanche parasitism whereas others were highly susceptible. Lines with high resistance to Orobanche can reduce the build-up of a seed bank of the parasite in areas where mainly food legumes are grown and can be of value for developing integrated Orobanche control systems. The laboratory screening, which is faster and cheaper, reliably predicted the field performance and hence retesting in the field can be restricted to those lines found resistant in the laboratory.