pleosporalean

Pleosporalean refers to fungi belonging to the order Pleosporales, a large and diverse group within the class Dothideomycetes of the phylum Ascomycota. Members occur worldwide and include saprobes, endophytes, and many plant pathogens, with significant agricultural impact. The order contains hundreds of genera organized into multiple families, such as Pleosporaceae, Didymellaceae, Pleurotheciaceae, and Massarinaceae.

Morphology and characteristics common to pleosporalean fungi include the production of dark, robust fruiting bodies typically formed as pseudothecia embedded in plant material or borne on surfaces. They produce bitunicate asci with fissitunicate dehiscence, containing pigmented, often septate ascospores. Many genera also have a recognized asexual state producing conidia of various shapes. While morphology remains useful for identification, modern taxonomy relies heavily on molecular phylogenetics to resolve relationships within the group.

Ecology and life history: Pleosporalean fungi occupy diverse habitats, including leaves, stems, wood, soil, seeds, and aquatic environments. They are predominantly saprotrophs, endophytes, or plant pathogens, contributing to leaf spots, stem cankers, fruit rots, and other crop diseases. A number of species are opportunistic pathogens of animals or humans in rare cases, but most attention centers on plant-associated life histories.

Significance and taxonomy: The group is ecologically widespread and economically important due to its roles as pathogens and decomposers. In recent decades, molecular data based on rDNA and other genes have reshaped the circumscription of Pleosporales, leading to renaming and reclassification of genera and families within the order.