Submitted to: Aflatoxin Workshop
Publication Type: Abstract only
Publication Acceptance Date: 10/30/2007
Publication Date: 2/20/2008
Citation: Horn, B.W., Peterson, S.W. 2008. Specificity of Eupenicillium and Penicillium species for the conidial heads of Aspergillus sections Flavi and Nigri. Aflatoxin Workshop. 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. 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 Penicillium species based on morphological and molecular characters, P. parvulum and P. georgiense. Phylogenic analysis using three loci shows that P. parvulum is a sister species of E. cinnamopurpureum and that P. georgiense is not closely related to P. parvulum or either Eupenicillium species, though its precise phylogenetic placement within the genus Penicillium is unresolved. Eupenicillium ochrosalmoneum, E. cinnamopurpureum, and P. parvulum sporulated predominantly on the heads of section Flavi species, including aflatoxigenic A. flavus and A. parasiticus. In contrast, P. georgiense was restricted to the heads of section Nigri species. Eupenicillium and Penicillium species were observed spreading from one Aspergillus head to another by means of aerial stolon-like hyphae. Internal hyphae within Aspergillus stipes were uncommonly observed (0-7%). Additional studies are required to clarify whether the Eupenicillium and Penicillium species are parasitic or simply epibiotic on their hosts.