Fungi associated with Pinus taeda L. seeds and effects on early seedling development

Abstract

Isolations from loblolly pine conelets, cones, seeds, and young seedlings yielded 61 fungous isolates. These isolates included one or more species of Aspergillis, Alternaria, Chaetomium, Cladosporium, Curvularia, Epicoccum, Fusarium, Gilmaniella, Geotrichum, Hyalodendron, Pestalotia, Penicillium, Rhizoupus, Syncephalastrum, and Trichothecium, plus 22 unidentified isolates. Pathogenicity was indicated for 16 of the 61 isolates in inoculation tests. Germination was reduced by 8 isolates (three Pestalotia, one F. moniliforme, and four unidentified isolates. Seven isolates were shown to be associated with high levels of seedling damping-off (50 - 100% of germinated seeds). These included three isolates of F. moniliforme, one Geotrichium, Pestalotia, Trichothecium, and one unidentified isolate. Reisolations from these diseased seedlings often yielded pure cultures of F. moniliforme. One isolate of Trichothecium was consistently associated with significant levels of abnormal seed germination in which the radicle did not penetrate the soil, with the seedling dying on the soil surface.