VIEW ARTICLE

Inhibition of Wood-Rotting Fungi by Stilbenes and Other Polyphenols in Eucaly ptus sideroxylon. John H. Hart, Associate Professor, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48823; W. E. Hillis, Chief Research Scientist, Forest Products Laboratory, Division of Applied Chemistry, CSIRO, South Melbourne, Victoria 3205, Australia. Phytopathology 64:939-948. Accepted for publication 18 January 1974. DOI: 10.1094/Phyto-64-939.

Heartwood of red ironbark (Eucalyptus sideroxylon) was not decayed in vitro by Polyporus versicolor or Poria monticola. Methanol extractives of heartwood diluted × 1,000 in 3% malt extract were toxic to P. monticola, but not to P. versicolor. Heartwood blocks extracted with methanol retained their decay-resistance. The ether-soluble (rich in stilbenes) and the water-soluble (rich in ellagitannins) fractions were inhibitory to both fungi in 3% malt extract at concns below that for both classes of compounds in the original wood. Impregnation of cottonwood (Populus deltoides) blocks with pure resveratrol (3,4’,5-trihydroxystilbene) did not result in decay resistance although relatively high proportions of the methanol extractives, and the water-soluble fraction did so. This study emphasized the difficulties in relating the results of in vitro testing of toxicity of wood extractives and their pure components with the durability of the wood from which the extractives were obtained.