Microsphaeropsis ochracea sp. nov. associated with dead apple leaves

Abstract

A new saprophyte species of Coelomycetes, Microsphaeropsis ochracea, is described based on an isolate recovered from apple leaf litter from Quebec, Canada. Although this isolate possesses conidia similar to those of Microsphaeropsis arundinis (Ahmad), there are several differences between the two species. M. ochracea forms pycnidia of 70 μm up to 120 μm into senescent apple leaf tissue and unlike M. arundinis they are not ostiolate when grown either on a apple leaf or on culture media. Conidiogenous cells are 4.5–10 × 2.5–4.5 μm, which is much larger than those described for M. arundinis. Reverse side of the colony presents a pale luteous to ochreous pigment that diffuses through the media. The description of this new isolate was compared with the published description of M. arundinis as well as with the dry specimen of the paratype.

• biocontrol
• Coelomycetes
• saprophyte
• taxonomy

We are grateful to Dr. G. Kinsey from the CABI Bioscience, England, for discussion on the taxonomy, for proof reading of the manuscript and for the Latin diagnosis. We are also grateful to Dr. N. Benhamou and Alain Goulet from Laval University, Quebec, Canada, for assistance with the electron microscopy.