Trichoderma stromaticum and its overseas relatives

Abstract

Trichoderma stromaticum, T. rossicum and newly discovered species form a unique lineage in Trichoderma. Phylogenetic and phenotypic diversity in Trichoderma stromaticum are examined in the light of reported differences in ecological parameters and AFLP patterns. Multilocus phylogenetic analysis using 4 genes (tef1, rbp2, cal, chi18-5) did not reveal phylogenetic basis for the two reported divergent AFLP patterns or for ecological parameters; however, this analysis does indicate incomplete speciation with one supported clade derived from within T. stromaticum that corresponds to AFLP Group 2 of de Souza et al. (2006, Phytopathology 96:61–67). Trichoderma stromaticum is known only from tropical America and is typically found in association with Theobroma cacao infected with Moniliophthora perniciosa. It is reported here for the first time on pseudostromata of M. roreri in Peru. Strains of T. stromaticum also have been isolated as endophytes from stems of Theo. cacao. There are no recognized close relatives of T. stromaticum in tropical America. The closest relatives of T. stromaticum are collected in Africa and Thailand; somewhat more distantly related are T. rossicum and T. barbatum, both found in north temperate regions.