Stephensia Shanori. I. Cytology of the Ascus and Other Observations

Cytological and developmental studies of the Tuberales have been greatly neglected. Only Tuber brumale auct. (Berlese, 1898), T. brumale var. melanosporum Vitt. (Greis, 1938, 1939), T. aestivum Vitt. (Schussnig, 1921; Greis, 1938, 1939), T. excavatum Vitt. (Hawker, 1954), and Hydnobolites sp. (Faull, 1905) were previously investigated cytologically. Ontogenetic studies of several species (see Discussion) have been reported. Observations in most of these studies were made on only a few specimens, in some cases already mature. Greater knowledge of the ontogeny and cytology in more species is necessary before the importance of these processes to relationships within the order can be decided.