Multiplex conidium morphology in species of theUlocladium atrumgroup

摘要

Cultures of many isolates ofUlocladiumPreuss mature with conidium populations dominated by dark, obovoid to spherical, densely ornamented spores similar to those of typicalUlocladium atrumPreuss. Early-growth conidia of such isolates frequently are quite different morphologically from those ofU. atrumand are considered to be useful in defining species within aU. atrumspecies group. Four species are compared from this viewpoint in both early-growth and late-growth stages:U. atrum, Ulocladium cucurbitae(Letendre amp; Roumeguère) Simmons,Ulocladium multiformeSimmons sp.nov. (from soil), andUlocladium dauciSimmons sp.nov. (from seed ofDaucus carotaL.).Key words:Ulocladium, classification, conidium variability