SIMPLE METHOD FOR SIMULTANEOUS QUALITATIVE AND QUANTITATIVE STUDIES OF FUNGAL BEHAVIOR IN SOIL

Predetermined numbers of conidia of Bipolaris maydis and B. stenospila , chlamydospores of Phytophthora cinnamomi and sporangia of Pythium sp lendens were added to small soil clumps placed on soil blocks. Most of these were observed and counted after the soil clumps were stained wi th rose Bengal and destained with a concentrated mineral solution. Aft er being added to soil, sporangia of Py. splendens became thick-walled and their ability to germinate decreased rapidly when the soil was am ended with 1 % chitin. Chitin amendment also increased the number of e mpty sporangia and sporangia with partially lysed cytoplasm. The techn ique should be useful for studying the change with time in the total n umber, morphology and viability of fungal propagules in soil under dif ferent environmental conditions, and for investigating mycoparasitism of fungal propagules in soil.