Invasion of lupin seed by Verticillium albo-atrum

Lupinus albus L. inoculated at 6 weeks and L. luteus L. at 11 weeks by stem injection with a spore–mycelium suspension of Verticillium albo-atrum Reinke and Berth. produced 2.5 and 6.8% infected seeds, respectively. Other methods of inoculation failed to produce seed infection. The pathogen was present internally in infected seeds of L. luteus, but in L. albus it was superficial. Histological observations indicated that plugs of amorphous material in infected vessels, and branching of the vessels, may serve as barriers to seed infection. Even the low levels of seed infection observed may have economically significant epidemiological implications.