VIEW ARTICLE

Ecology and Epidemiology

Effect of Volatile Compounds From Remoistened Plant Tissues on Growth and Germination of Sclerotia of Sclerotium rolfsii. M. K. Beute, Professor, Department of Plant Pathology, North Carolina State University, Raleigh, 27650; R. Rodriguez-Kabana, professor, Department of Botany and Microbiology, Auburn University, Auburn, AL 36830. Phytopathology 69:802-805. Accepted for publication 9 February 1979. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-802.

Germination of sclerotia and growth of Sclerotium rolfsii, which were stimulated by volatile compounds from remoistened, undecomposed plant tissues, were most pronounced when CO₂ was removed and O₂ added in 24-cm-diameter, 9.9 L desiccators. Germination of sclerotia and growth of S. rolfsii were increased by remoistening dried green tissue from alfalfa, corn, crotalaria, kudzu, lespedeza, peanut, and ramie. In a survey of 71 organic volatile compounds, two alcohols (including methanol), three aldehydes, two esters, and two halogenated hydrocarbons were as stimulatory as remoistened peanut hay to sclerotial germination of S. rolfsii. Methanol (about 2–4 μl/g hay) was detected by microdiffusion analysis of remoistened peanut hay. Germination of sclerotia of S. rolfsii was equal (P = 0.05) in the presence of methanol (7 μl) or peanut hay (2 g) in the desiccators. Addition of pectinase to 1% pectin also increased germination of sclerotia and growth of S. rolfsii; enzymatically released methanol may be a major stimulant emanating from remoistened, undecomposed plant tissue. The pectin-methanol hypothesis which is proposed in this study may explain, in part, the wide host range of S. rolfsii. These results also expand the list of known stimulants and inhibitors of sclerotial germination of S. rolfsii.