Naemacyclus fimbriatus . [Descriptions of Fungi and Bacteria

Abstract

Abstract A description is provided for Naemacyclus fimbriatus . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: VUJANOVIĆ, ST-ARNAUD & NEUMANN (1998) have provided the only report suggesting that Naemacyclus fimbriatus can cause infections of living needles of Pinus species. They observed chlorotic and necrotic second- and third-year needles of Pinus rigida bearing ascomata identified as this species. The fungus was successfully isolated into pure culture from those needles, and from dead fallen cones, presumably of the same pine. They speculated that 'unfavourable conditions such as the more than 200 days with frost and thin organic or mineral soil layer may predispose pitch pine to infection by this fungus'. The apparent absence of this fungus from higher latitudes in Europe noted below seems, at first sight, incompatible with this observation. HOSTS: Pinus brutia, P. halepensis, P. maritima, P. nigra var. maritima, P. nigra var. pallasiana, P. nigra, P. pinaster, P. resinosa, P. rigida, P. sylvestris, P. sylvestris subsp. kochiana, P. taeda, P. uncinata, P. virginiana, Pinus sp. (bark, cones, cone scales and leaves). GEOGRAPHICAL DISTRIBUTION: NORTH AMERICA: Canada (Québec), USA (Georgia, Massachusetts, Pennsylvania). EUROPE: Austria, Czech Republic, France, Republic of Georgia, Greece, Hungary, Netherlands, Poland, Spain, Switzerland, UK, Ukraine. TRANSMISSION: Not known. Presumably by air-borne ascospores released in humid conditions. VUJANOVIĆ, ST-ARNAUD & NEUMANN (1998) reported that Naemacyclus fimbriatus produces 1-3 brown mycelial cords, 50-100 μm diam., which grow through the litter from ascomata in autumn. They were unable to explain the nature of these cords, which have never been observed by the present author. In two species of fungi inhabiting living conifer leaves ( Didymascella thujina, IMI Descriptions No. 1334 and Rhabdocline pseudotsugae, IMI Descriptions No. 651, both possibly members of the Rhytismatales ), ascospores have been observed to germinate while still inside the ascus and it is possible that hyphae resulting from these germ tubes may grow out of the ascoma and cause further infections. Those two species are, however, undoubtedly rather distant from Naemacyclus fimbriatus and their germination, in any case, is always associated with a darkening of one cell of the ascospore, a phenomenon not reported by VUJANOVIĆ, ST-ARNAUD & NEUMANN (1998). The mycelial cords they observed therefore remain unexplained.