METABOLITES OF OPHIOSPHAERELLA-HERPOTRICHA, A CAUSE OF SPRING DEAD SPOT OF BERMUDAGRASS

Ophiosphaerella herpotricha, a cause of spring dead spot (SDS) of berm udagrass, produced seven metabolites in liquid culture. These were iso lated and structurally identified as epoxydon, desoxyepoxydon, phyllos tine, m-hydroxybenzyl alcohol, a cyclic peptide, destruxin-B, and two novel metabolites, dihydroxy-6-(2-hydroxyethyl)-3-methoxyacetophenone and oxy-4,5-dihydroxy-2-hydroxymethylcyclohex-2-enone. All metabolites , except destruxin-B, caused necrosis when spotted onto leaves of berm udagrass and other plant species. Destruxin-B, previously reported as a host-specific toxin on Brassica napus, failed to cause necrosis on l eaves of bermudagrass cultivars susceptible to SDS. Bermudagrass culti vars varied in their sensitivity to epoxydon, the major metabolite iso lated. However, there was no correlation between the amount of leaf ne crosis caused by epoxydon and resistance of the cultivars to SDS in th e field.