01980naa a2200205 a 450000100080000000500110000800800410001910000190006024500740007926000090015352014500016265000100161265000140162265300150163665300160165165300110166765300130167870000200169177300630171110758841996-02-01       1983    bl ---       0--  u    #d1 aFILONOW, A. B.  aMycostasis in relation to the microbial nutrient sinks of five soils.  c1983  a[14C]exudation from fungal propagules on 5 soils over 4-24 h was studied in relation to mycostasis. [14C]exudation from sclerotia of Macrophomina phaseolina, chlamydospores of Thielaviopsis basicola, and conidia of Cochliobolus victoriae after 24 h on two sandy loam soils and a loam was generally greater than exudation on the two clay loam soils. Results were similar for conidia of Stemphylium sarcinaeforme but differences were not statistically significant. When natural soils were pulsed with [14C]glucose, 14CO2 evolved by the soil microflora over 2-12 h showed a similar trend. [14C]exudation from M. phaseolina sclerotia and C. victoriae conidia incubated on soils was greater than that from propagules incubated aseptically on a bed of sand through whichwater percolated at a flow rate sufficient to inhibit germination. Propagules of C. victoriae, M. phaseolina and T. basicola germinated greater on one or more of the coarse-textured soils than on fine-textured soils. Using y-irradiated soils, more [14C]exudate was adsorbed by the clay loams than by the loam and sandy loam soils, suggesting that the adsorptive capacity of soils may be an important factor in controlling fungal utilization of soluble nutrients. Fungal germination in soil appears to be jointly influenced by two opposing tendencies: the ease with which germination occurs in response to exogenous nutrients and the amount of endogenous substrate lost or retained.  afungi  aNutriente  aFungistase  aFungistasis  aFungos  aNutrient1 aLOCKWOOD, J. L.  tSoil Biology and Biochemistrygv.15, n.5, p.557-565, 1983.