First record of Sclerotinia laxa Aderh. Ruhl. in New South Wales: differentiation from S. fructicola (Wint.) Rehm. by cultural characteristics and electrophoresis

Abstract

Sclerotinia laxa is recorded for the first time in New South Wales, at Orange. A survey indicates that the disease is confined to the Central Tableland. The disease was detected on Chaenomeles spp. (flowering quince), Prunus domestica (European plum), Prunus persica (nectarine) and several ornamental Prunus species (flowering cherries, apricot and peach). Cultural characteristics and acrylamidc-gel clectrophoresis were used to compare several of these isolates with isolates of S. fructicola from New South Wales and with S. laxa from Victoria. Isolates of S. laxa from South Australia and Tasmania were also studied in culture. The general colony lobing and the absence of hyphal anastomoses between germinating conidia can be used to identify S. laxa. Other cultural features found to be of little value for identification are discussed. The electrophoretic patterns for several enzymes clearly distinguished S. laxa from S. fructicola, and these representative reference patterns are useful for species identification.