COLONIES rather slow-growing, ca. 3.5-4.0 cm diam after 10-day growth at 20oC on potato dextrose agar (PDA), velvety, brick, dull orange to orange-brown because of the pigmented conidiophores and conidia.
CONIDIOPHORES (cp) erect, pale orange-brown, 200-370 4-5 µm high, repeatedly verticillately branched in one to several orders.
Phialides (ph) slender, flask-shaped, hyaline, 12-23 x 2-4 µm.
CONIDIA (c) oval, pale reddish-brown in mass, 3.5-5.0 x 2.0-2.5 µm, at first single, later in globose to subglobose aggregations.
SUBSTRATE AND DISTRIBUTION. Verticillium tenerum commonly grows on different organic remnants (Domsch et al. 1980; Fassatiova 1983). It has also been isolated from cloth, paper, dung, milk, macromycete sporocarps, and soil.
Verticillium tenerum occur in the whole world (Domsch et al. 1980).
NOTES. The teleomorph of V. tenerum is Nectria inventa Pethybr.
Verticillium tenerum has been shown in vitro to be an antagonist of many plant pathogens, including, e. g., Phytophthora cactorum (Leb. & Cohn) Schrot., and a mycoparasite of Alternaria brassicae (Berk.) Sacc. (Domsch et al. 1980).
Domsch K. H., Gams W., Anderson T. 1980. Compendium of soil fungi. Acad. Press. London-New York-Toronto-Sydney-San Francisco.
Fassatiova O. 1983. Grzyby mikroskopowe w mikrobiologii technicznej. Wydawnictwo Naukowo-Techniczne, Warszawa.