Sources of Resistance to Crenate Broomrape Among Species of Vicia.

Crenate broomrape is a parasitic weed that represents a major constraint for pulse and forage legume production in the Mediterranean and West Asia regions. Control strategies have centered around agronomic practices and the use of herbicides, although success has been marginal. Resistance breeding is hampered by scarcity of proper sources of resistance and of a reliable and practical screening procedure. A germ plasm collection of 208 accessions of vetch belonging to 42 Vicia spp. was screened for resistance to crenate broomrape under field conditions. High levels of resistance were found in several species. Resistance of selected accessions was confirmed by a low induction of broomrape seed germination in pot and in vitro experiments. This was followed by a scarce establishment of broomrape radicles in contact with host roots and a limited development of established tubercles. In addition, a hypersensitive-like necrosis occasionally was observed, but at low frequency.