EFFECT OF SUCROSE CONCENTRATION ON SCLEROTIA PRODUCTION AND SUBSEQUENT APOTHECIAL FORMATION BY SCLEROTINIA-SCLEROTIORUM

The number, range of individual and total fresh weight of sclerotia produced by an isolate of Sclerotinia sclerotiorum increased linearly with sucrose concentration. Mean weight of sclerotia had a long-normal distribution with respect to sucrose concentration and incresaed to a maximum at 3 and 5% w/v sucrose. Without any pretreatment, carpogenic germination of sclerotia began between 2-7 wk on moist filter paper under the same environmental conditions used for sclerotium production. Apothecial production increased with time, maximal production taking place after 6-10 wk from sclerotia from low sucrose concentrations. Formation was slower from sclerotia from higher sucrose levels and none were formed on sclerotia produced at 3 and 5% sucrose. Carpogenic germination was restricted mainly to sclerotia less than 10 mg. Production of a single apothecium per sclerotium was more frequent than multiple apothecia production.