Submitted to: Mycological Society of America
Publication Type: Abstract only
Publication Acceptance Date: 3/28/2007
Publication Date: 9/4/2007
Citation: Horn, B.W., Peterson, S.W. 2007. Host specificity of Eupenicillium ochrosalmoneum, E. cinnamopurpureum, and two new Penicillium species associated with the conidial heads of Aspergillus. Mycological Society of America. Interpretive Summary: None required.
Technical Abstract: The genus Penicillium comprises species that mostly colonize plant matter. However, early reports suggest that several species are capable of parasitizing Aspergillus and sporulating on the conidial heads of the host. More recently Eupenicillium ochrosalmoneum and E. cinnamopurpureum, both with Penicillium anamorphs, have been observed sporulating on the heads of Aspergillus species belonging to section Flavi during the colonization of peanut seeds. Little is known about the host specificity underlying these Aspergillus–Penicillium associations. In this study, Aspergillus species representing nine taxonomic sections were paired in culture with E. ochrosalmoneum, E. cinnamopurpureum, and two new species described here based on morphological and molecular characters, P. exiguum and P. georgiense. Phylogenic analysis using three loci shows that P. exiguum is a sister species of E. cinnamopurpureum and that P. georgiense is not closely related to P. exiguum or either Eupenicillium species, though its precise phylogenetic placement within the genus Penicillium is unresolved. Eupenicillium ochrosalmoneum, E. cinnamopurpureum, and P. exiguum sporulated predominantly on the heads of section Flavi species. In contrast, P. georgiense was restricted to the heads of section Nigri species. All species spread across Aspergillus colonies by means of aerial hyphae that grew from head to head. Additional studies are required to clarify whether the Eupenicillium and Penicillium species are parasitic or simply epibiotic on their hosts.