Twigs entangled by rhizomorphs of Marasmius crinisequi inside tea bushes are ostly devoid of leaves. This was found to be due to the emission of a defoliation-inducing volatile by the rhizomorphs, because when tea twigs were enclosed with rhizomorph sections of M. crinisequi, leaf fall occurred within 5 days. Leaves on control twigs remained healthy and attached. The volatile substances emitted from rhizomorphs were passed through acetone and the volatile compounds in acetone were analyzed by GC/MS. The emitted volatiles were identified as 3-oxo-β-ionol, ,4,6-tri-ter-butyl-4-
methyl-cyclohexadien-2,5-one and 2-phenyl-3,4,5,6-tetramethylpyridine. These compounds have not been reported from fungi or plants prior to this report. The
significance of the production of a defoliation-inducing volatile by rhizomorphs of M. crinisequi in its acquisition of nutrients from tea leaves in the competitive environment is discussed.
