Abstract
The Fungus Sclerotinia sclerotiorum (Lib.) de Bary was isolated based on morphological and microscopic characteristics and on molecular by using Polymerase chain reaction (PCR) with the Primer 18S rRNA. The isolation Propagation of the fungus using Wheat grain media was used in order to gain as much as possible from the sclerotia and using these sclerotia in the next experiments . The environment condition ie. temperature ,light,and darkness effects on the production of Apothecium ,Ascus and Ascospores produced from the sclerotia were also studied. Results revealed that the primer used in fungal diagnosis was capable to do that in the Fungus ، and 25 c0 and light effect on the stipes and Apothecium production from sclerotia were effective temperature at 10,15 and 20 c0 with the presence of light were suitable for Apothecium production .Without light , Apothecium stays without growth completion and remains on stipe elongates under the dark condition. Distilled water is considered the best medium for sclerotia formation and development of stipes.