COMPARISON OF AERIAL AND SUBMERGED SPORE PROPERTIES FOR TRICHODERMA-HARZIANUM

Spores produced by aerial mycelium of Trichoderma harzianum P1, a pote ntial biocontrol agent, showed both higher UV-resistance and longer vi ability after storage than those produced within liquid media ('submer ged' spores). Aerial spores were produced in clusters, had a thick out er wall, and few organelles. Trehalose content was significantly lower than in submerged spores. Conversely, submerged spores were mostly co llapsed, not clustered and larger than aerial spores. They had many cy toplasmic organelles and a thinner outer wall. These spores were hydro philic, while aerial ones were highly hydrophobic. On analysis, the la tter was related with the presence of a single major low molecular mas s protein (< 14 kDa). This protein was nearly absent in extracts from walls of submerged spores but was found in the extracellular medium. A n involvement of the outer wall layer in the resting state of T. harzi anum spores is proposed.