Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 70. (Budapest 1978)

P. Komáromy, Zs.: Scotiella species (Chlorophyceae) and their theoretical life-cycle

SS Zs. P.—KOMÁROMY Neither CHODAT (1902) nor WILLE (1903) referred to any autosporulation in the case of Sc. nivalis. Yet, FRITSCH interpreted some of WILLE'S observations as "the apparent formation of new individuals by subdivision of the cell-contents" (I.e. p. 310.). These unclear and rather incomplete information have been considered later as facts. I think, in the cited cases the chloroplasts were in different desorganizational stages and the phenomena observed were interpreted as reproduction by autospores. In the subsequent examinations the descriptions of the new Scotiella species include more and more information concerning the Scotiella genus. HOLLERBACH (1936) in the case of soil inhabiting Sc. levicostata described and drew the real autosporulation of this species (Plate I: Fig. 7). JAO (1947) enriched the genus with two new species (Sc. sinica and Sc. oboviformis). He established: "As the reproduction methods of this genus are hitherto nearly unknown its systematic position is still uncertain" (p. 249). In his materials the vegetative reproduction of the species were very frequent. It happened by autospores (Figs. 1 and 2 in the text), so he referred the Scotiella genus to Oocystaceae (I.e. p. 249). REISIGL (1964) isolated the Sc. terrestris from alpine soil and he gave an exact description of the vegetative reproduction of this species from culture (Plate III: Figs. 2a-b). He pointed out, that the young cells of Sc. terrestris have one parietal chloroplast and the aged ones have numerous chloroplasts. The earlier data about Scotiella species originated from specific biotopes, namely, from snow occurring on crystalline rocks (PASCHER 1943). The peculiar ecological conditions caused morphological similarity thus to identify the different Scotiella species we do not need to know the whole lifecycle. Because the reproduction of cells occurred very rarely in snow, and the cells usually contained much food reserve like the spores, I think the Scotiella cells may be in resting and desorganizational stages on snow. They are growing on alpine soils in vegetative stage, and in autumn they multiply vigorously. If the weather is unfavourable, the cells go to rest or into desorganizational stage, and they are transferred into the snow by wind, but most of the cells may live and some of them may multiply on melting snow, too. II. Change of characteristics of Scotiella levicostata during life-cycle Material and methods — I decided to investigate the life-cycle of this species, to clarify the values of the main characteristic features. During the floristical researches of the Hortobágy National Park numerous soil samples were taken in different times of the year (5.9.1974; 14.11.1975; 23.3.1976; 21.4.1976; 10.9.1976). In some of the samples which were collected in Artemisio-Festucetum pseudovinae near Újszentmargita village and in GalatelloPeucedanetum near Ohat village, there are numerous Scotiella cells in different stages: in vegetative, reproductive and desorganizational ones. They were identified as Scotiella levicostata HOLLERB. (Plate II: Figs. 1-4). The enrichment cultures made from soil samples were kept on shelves, at room temperature, they were moistened with distilled water and they were Fig. 1. Scotiella sinica by JAO (1947). — Fig. 2. Scotiella oboviformis by JAO (1947)