ASCOMAL DEVELOPMENT IN MELANOSPORA-ZAMIAE

The characteristics of ascomal development in Melanospora zamiae conformed to the ascohymenial type of ontogeny, in which the ascoma, a perithecium, developed from a coiled ascomal initial, which was eventually enclosed by investing hyphae that formed the walls. The centrum was composed of two tissues: a centrum prosenchyma composed of several layers of flattened cells that line the ascomal wall, and the centrum pseudoparenchyma that filled the center of the ascoma both above and below the layer of asci. Both the suprahymenial and subhymenial pseudoparenchyma tissues disintegrated as the asci matured, whereas the centrum prosenchyma remained intact. No paraphyses were formed. The ascogenous system was differentiated from the ascogonial cell and the asci formed from binucleate ascus mother cells without the formation of croziers, resulting in asci of different ages in a single perithecium. Ascomal ontogeny in M. zamiae showed similarities to the Sordaria and Diaporthe types of ontogeny, but also differed from them in the lack of paraphyses.