Trichoderma viride Pers. ex Gray


5-day old
10-day old

 

COLONIES fast-growing, at first low, gossamery, hyaline, later comapact, cottony, with small, yellow green to dark green conglomerations of conidia, of a coconut smell, 10 cm diam when 5- and 10-day old and grown on potato dextrose agar (PDA) at a room temperature; reverse hyaline with a pale green border.

Hyphae (h) septate, light oliviaceous, smooth, 3.1-5.0 µm wide.

 

 

CONIDIOPHORES (cp) pyramidally branched, i. e., with short branches (cpb) formed near the tip and longer branches with secondary branches in the lower part.

Phialides (p) flask-shaped, 2.5-3 µm wide, arranged in divergent groups of 2-4, slender and irregularly bent, formed at the top of both the main hypha and its branches.


CONIDIA (c) almost globose, greenish to green, 3.6-4.5 x up to 4.8 µm, usually roughened.

 

 


SUBSTRATE AND DISTRIBUTION. Trichoderma viride is one of the most widely distributed soil fungi in the world (Domsch et al. 1980). Its teleomorph, Hypocraea rufa (Pers. ex fr.) Fr. has been frequently encountered on decaying wood in different temerate regions of Europe (Domsch et al. 1980).


NOTES. Trichoderma viride is one of the most important and the best known mycoparasites and aggresive competitors of many plant pathogens (Cook and Baker 1983). Growth of mycelia of T. viride along and coiled around hyphae of different fungal hosts has been observed. Penetration of host mycelia by T. viride has also been found. This resulted in vacuolization and finally in total degeneration of their cells. Hyperparasitisms of T. viride has been observed on, e. g., Sclerotinia spp., Claviceps purpurea (Fr.) Tul., Fusarium and Phytophthora spp., and Rhizoctonia solani Kühn (Domsch et al. 1980).

Trichoderma viride is used in the commercial production of the enzyme cellulase (Alexopoulos et al. 1996).


REFERENCES

Alexopoulos C. J., Mims C. W., Blackwell M. 1996. Introductory mycology. Fourth edition. John Wiley & Sons, INC. New York, Chichester, Brisbane, Toronto, Singapore.

Cook R. J., Baker K. F. 1983. The nature and practice of biological control of plant pathogens. The American Phytopathological Society. St. Paul, Minnesota.

Domsch K. H., Gams W., Anderson T. 1980. Compendium of soil fungi. Acad. Press. London-New York-Toronto-Sydney-San Francisco.