VIEW ARTICLE

Conservation of Mycelial Constituents in Four Sclerotium-Forming Fungi in Nutrient-Deprived Conditions. Christos Christias, Research Associate, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48823, Present address of senior author: Nuclear Research Center “DEMOCRITUS”, Athens, Greece; J. L. Lockwood, Professor, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48823. Phytopathology 63:602-605. Accepted for publication 17 November 1972. DOI: 10.1094/Phyto-63-602.

Sclerotia were formed when washed mycelial mats of Sclerotinia sclerotiorum, Sclerotium rolfsii, Sclerotium cepivorum, and Rhizoctonia solani were incubated on soil, on a bed of glass beads leached with slowly running water, or on a bed of water-saturated glass beads without leaching, Sclerotium formation was accompanied by extensive mycelial lysis. For mycelia incubated on leached glass beads, 39-52% of dry matter, 27-58% of carbohydrates, and 42-79% of nitrogen originally present were conserved in sclerotia of the four fungi. For mycelia incubated on soil, amounts conserved were usually slightly higher. When mycelia of S. rolfsii were incubated on leached glass beads, 42% of the total mycelial carbohydrate was incorporated into sclerotia, 25% was lost in exudates, 26% was lost as CO₂, and 7% was recovered in the residual mycelium; 44% of the total nitrogen was incorporated into sclerotia, 43% was lost in exudates, and 13% was recovered in the residual mycelium. Nutrient deprivation may induce the formation of sclerotia from mycelial reserves and products of mycelial lysis.