B. Papp szerk.: Studia Botanica Hungarica 34. 2003 (Budapest, 2003)

Vasas, Gizella: Investigations on macrofungi production effected by fungistasis at Pilisszentkereszt (Hungary)

higher than those of mycorrhizal ones at both the Bacillus subtilis treated and the control sites. The number of fruit-bodies (206) of the subdominant saprotrophic species is higher than that of the eudominant saprotrophic species (57) similarly to the investigations carried out 16 years ago. Due to a monthly treatment by Bacillus subtilis the number of fruit-bodies of saprotrophic fungi became 3 times as much (784) compared to that of the control site (263). It is interesting that while the number of subdominant species (575) became almost 3 times as much in the control site, the number of fruit-bodies of eudominant species became 4 times as much (209). The numbers of species of wood decaying fungi are equal in the two sampling sites in the spruce forest, however, the number of fruit-bodies in the treated area is twice as much as in the control. The results received in the spruce forest are similar to those obtained in the deciduous forest: the production of the secondary decomposer saprotrophic fungi species became multiple due to the Bacillus subtilis treatment. In the case of wood decaying species the number of species and fruit-bodies became twice as much after the 3-year Bacillus subtilis treatment. Supposedly as a result of the treatment, new species entered in the succession in the last year while in the spruce forest, where the investigation lasted for 2 years only, the number of species remained unchanged but the number of fruit-bodies was already effected by the bacterium. CONCLUSIONS In the two sampling sites (deciduous forest, spruce forest) treated by Bacillus subtilis, the primary decomposer and mycorrhizal fungi did not show obvious difference between the treated and control sites in the number of fruit-bodies, but in the case of the secondary decomposer saprotrophic species the number of fruitbodies increased strikingly. One of the reasons might be the assisted nutrient uptake, since in case of the secondary decomposer species Bacillus subtilis starts the decomposition, thus the nutrient uptake is easier for the species of macrofungi. The other possible reason is the protective function. Bacillus subtilis produces fungistatic substances (polypeptide antibiotics: subtilin) which inhibit or slow down the growth of other competitor organisms. It has some, (though limited) inhibiting effect also on macrofungi, so they have an advantage compared to those of other soil-inhabiting competitor micro-organisms. Consequently, fungi can develop faster, which is clearly seen also in the production of fruit-bodies according to our results. Fungistasis is presumably important also in the case of mycorrhizal fungi,