Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 8. (Budapest 1957)

Bohus, G.: On the results of researches concerning the temperature claims of macroscopic fungi

From the point of view of temperature optimum, the species studied may be relegated into 7 groups (Table 3). The temperature optimum of the majority of species (77%) is between 19—22°, that is, between 23—26°. The temperature optimum of some species comes higher than this, between 26—31,5°. In this latter temperature interval, the developmental rate of the mycelia of most species is already on the decrease. Finally, the mycelia of the majority of the species cease to develop between 3í,5° and 34,5°. However, the mycelia of certain species still continue to develop even on this higher temperature. At this point, we may establish two facts. The first is that Phallus impudicus reaches its optimal development at this temperature interval and shows by this high temperature claim further indications toward its relation-groups, the members of which are in their majority tropical and Mediterranean species. The second point is that the mycelia of species show a further development (in many cases a good development) on this high temperature which live in grassy (eventually grovy) and sunshiny areas, where the higher warming up of the soil occurs regularly even on our climate. 2. From the point of view of temperature claims, certain types may be distinguished (Fig. 1). On the basis of the known temperature claims of terricolous mycelia, it can be established that in the season of vegetational period in Hungary, and at a suitably corresponding soil humidity, the mycelium has its optimal development in June, July and August, when the monthly temperature mean (which is a value near the mean temperature of the soil) approaches the temperature optimum of the mycelia of most fungus species. (For Budapest, the monthly temperature mean of 30 years — 1901 — 1930 — is 19,6° for June, 21,6° for July, and 20,6° for August). The mycelia of the macroscopic fungi develop rather well in May and September, when the monthly temperature mean (for Budapest) is 16,4° in May, and 16,3 in September. 3. On the basis of researches, inferences can be drawn concerning the developmental rate of the mycelia of several species. Of these observations, however, only the most conspicuous can be considered, as the developmental rate observable on malt agar frequently disagrees with the developmental rate found on the natural media of the given fungus species. It can be established that the developmental rate of the mycelia of Ascomycetes (Morchella and Verpa species) used for our researches is twice or even three times as much as that of the most quickly growing Basidiomycetes we studied. So, for instance, the mycelium of Morchella esculenta grows 15 cm per 10 days at the temperature optimum. 4. As concerns the parallelism between the temperature claims of the developing mycelia and the building of the fruit bodies, comparisons can but be made in a restricted measure. Namely, whilst temperature is, aside of humidity, the deciding factor among the conditions acting on the development of the mycelium on a suitable culture media, there are other factors besides humidity and temperature playing an important role during the growth of the fruit body. It can be stated generally that the temperature claims of the mycelium and the fruit body may be identical but they may also be different. For this latter case, Collybia velutipes serves as one of the best examples, since the temperature optimum for its mycelium is between 23—26° (60 mm during iö days), — and even though it develops almost as well at 27,5—31,5° (56 mm during 10 days), — the growth of the fruit body begins generally in the cold autumnal weather (10° or below).