VIRULENCE CHARACTERISTICS OF A NEW RACE OF THE PARASITIC ANGIOSPERM, STRIGA GESNERIOIDES, FROM SOUTHERN BENIN ON COWPEA (VIGNA-UNGUICULATA)

An in vitro growth system was used to determine the virulence of two s amples of Striga gesnerioides from Zakpota in southern Benin. Cowpea v ariety B301, previously considered resistant to all races of S. gesner ioides, was susceptible to both samples of the parasite. Two other cow pea varieties, 58-57 and IT81D-994, were totally resistant, Resistance in 58-57 was associated with a hypersensitive necrosis of infected ro ots, whilst IT81D-994 supported production of small S. gesnerioides tu bercles with stems which failed to develop. Striga gesnerioides from s outhern Benin is the fourth race of the parasite to be identified, and the first with virulence on variety B301. The implications for breedi ng cowpeas with resistance to S. gesnerioides are discussed.