Examination of sclerotial germination in Sclerotinia minor with an in vitro model

Abstract

An in vitro model was developed to examine the effect of surface microflora and exogenous nutrient on sclerotial germination of Sclerotinia minor. Germinated sclerotia were identified by the presence of appressoria on the plastic Petri dish. Surface sterilised field sclerotia germinated at maximum rates on water agar, but unsterilised sclerotia failed to germinate, even after drying and rewetting, indicating that sclerotia of S. minor are unlikely to germinate spontaneously in the presence of soil microflora. Partial surface sterilisation gave intermediate germination rates, which were enhanced two- to four-fold by treatment with sunflower root sap. There was no significant difference in the..