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United States Department of Agriculture

Agricultural Research Service


item Samuels, Gary
item Suarez, Carmen
item Solis, Karina
item Holmes, Keith
item Thomas, Sarah
item Ismaiel, Ed - Ed
item Evans, Harry

Submitted to: Mycological Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2006
Publication Date: 5/4/2006
Citation: Samuels, G.J., Suarez, C., Solis, K., Holmes, K.A., Thomas, S.E., Ismaiel, A.A., Evans, H.C. 2006. Trichoderma theobromicola and t. paucisporum: two new species from south america. Mycological Research 110:381-392.

Interpretive Summary: Fungi in the genus Trichoderma are effective in the biological control of fungi that cause plant diseases. They have been especially useful in controlling the two most serious diseases of the chocolate tree (cacao) in South America. In this research a survey was made of isolates of Trichoderma in Ecuador and Peru that occur in the living trunks of cacao trees. Two new species of Trichoderma were discovered and are named, described and illustrated. These fungi were tested for their effectiveness in controlling the diseases of the chocolate tree and found to demonstrate an antibiotic effect against the fungus that causes one of the serious diseases of the chocolate tree. This research will be used by plant pathologists who are working to control the diseases of the chocolate tree in South America.

Technical Abstract: The new species Trichoderma theobromicola and T. paucisporum are described. Trichoderma theobromicola was isolated as an endophyte from the trunk of a healthy cacao tree (Theobroma cacao, Malvaceae) in Amazonian Peru; it sporulates profusely. Trichoderma paucisporum is represented by two cultures that were obtained in Ecuador from cacao pods partially infected with frosty pod rot, Moniliophthora roreri; it sporulates sporadically on common media except SNA, cultures most often remaining sterile; it sporulates more reliably on SNA but produces few conidia. Trichoderma theobromicola could be reintroduced into cacao seedlings through shoot inoculation and was recovered from stems but not from leaves, indicating that it is an endophytic species. Both produced a volatile/diffusable antibiotic that inhibited development of M. roreri. Both species demonstrated antibiotic effect against M. roreri in in vitro and on-pod trials.

Last Modified: 10/17/2017
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