Observations on the anamorphs of six species of Diatrype and Diatrypella

Abstract

Cultures and anamorphs of six species of Diatrype and Diatrypella are described. Diatrypella favacea produces conidia from sympodially proliferating conidiogenous cells, whereas Diatrype stigma produces conidia from percurrently proliferating (annellated) conidiogenous cells. Both of these types of conidiogenous cell proliferation were found in Diatrypella verrucaeformis, Diatrypella pulvinata, Diatrype virescens, and Diatrype albopruinosa. Both the sympodial and percurrent modes of conidiogenous cell proliferation appear to be associated with holoblastic conidiogenesis.

Molecular phylogenetic studies on the Diatrypaceae based on rDNA-ITS sequences

“…Within this group we found a robust subclade containing one strain of Eutypa lata and two strains of Eutypa armeniacae showing identical sequences. Although this could support the hypothesis that both species are synonyms, as suggested by several authors (Glawe 1992, Rappaz 1987a, two other Eutypa lata isolates are peripheral to this subclade. DeScenzo et al (1999) assessed the genetic diversity in a group of Eutypa lata-like isolates from California using ITS sequencing and AFLP fingerprint and their results supported the separation of the two species.…”

“…This is consistent with the heterogeneity of the genus hypothesized by many authors, most likely as a consequence of the low number of diagnostic features exhibited. Although without bootstrap support, each Eutypa clade associated with some Cryptosphaeria species, in agreement with the presumed relationship between the two genera suggested by their similarity in stromatal morphology (Wehmeyer 1975, Glawe andRogers 1984).…”

“…However, stromatal configuration remains an important diagnostic feature to distinguish among the genera within the family (Glawe and Rogers 1984 (Glawe andRogers 1984, Rappaz 1987a). Three form-genera have been applied to diatrypaceous anamorphs, i.e., Cytosporina Sacc., for fungi with enclosed (pycnidial) conidiomata and filiform conidia; Libertella Desm., for those with unenclosed (acervular) conidiomata and filiform conidia and Naemospora Sacc., for fungi with unenclosed conidiomata and allantoid conidia (Glawe and Rogers 1984). However, there has been a reluctance to assign names to the anamorphs found in culture (e.g., Glawe andRogers 1984, Rappaz 1987a) because of the unclear limits among those form-genera and because many species produce anamorphs of different types.…”

“…Three form-genera have been applied to diatrypaceous anamorphs, i.e., Cytosporina Sacc., for fungi with enclosed (pycnidial) conidiomata and filiform conidia; Libertella Desm., for those with unenclosed (acervular) conidiomata and filiform conidia and Naemospora Sacc., for fungi with unenclosed conidiomata and allantoid conidia (Glawe and Rogers 1984). However, there has been a reluctance to assign names to the anamorphs found in culture (e.g., Glawe andRogers 1984, Rappaz 1987a) because of the unclear limits among those form-genera and because many species produce anamorphs of different types. For instance, Eutypella parasitica produces both pycnidia and acervuli on both natural substrata and agar media (Glawe 1983).…”

“…However, there has been a reluctance to assign names to the anamorphs found in culture (e.g., Glawe andRogers 1984, Rappaz 1987a) because of the unclear limits among those form-genera and because many species produce anamorphs of different types. For instance, Eutypella parasitica produces both pycnidia and acervuli on both natural substrata and agar media (Glawe 1983). Likewise, conidial ontogenesis varies highly in the group and different types of conidiogenesis (e.g., sympodial and percurrent) have been reported in the same strain (Glawe and Rogers 1982a, b).…”