INDUCTION OF MACROSCOPIC STRAND FORMATION IN SCLEROTIUM ROLFSII BY TRICHODERMA HARZIANUM

Sclerotium rolfsii Sacc. produced macroscopic multihyphal mycelial strands when growing over a Trichoderma harzianum colony. Direct contact between S. rolfsii and a viable colony of T. harzianum was essential for induction of strand development. Trichoderma harzianum induced strand formation on a medium supplemented with di- or polysaccharides consisting of glucose monomers but not when grown on glucose supplemented media. However, when mycelia of S. rolfsii grown on a glucose supplemented medium grew over a T. harzianum colony grown on a glucoseless medium, S. rolfsii still produced mycelial strands. It is suggested that the aggregated mycelial strand enables the plant pathogen to grow through soil or over an inhospitable surface.