اثر دما بر رشد رویشی قارچ Botrytis cinerea روی محیط‌کشت و پوسیدگی میوه کیوی رقم هایوارد

.Botrytis cinerea Pers. is one of the most important pathogens of fruits in cold storage, vegetables, ornamental plants, and greenhouse plants. In this study, infected kiwifruits were collected from the cold storage and the fungus was directly cultivated from the fruit on PDA medium. The cultures were incubated at 25 ℃ and dark conditions for 7–10 days. After the initial identification of the fungus and purification using the hyphal tip method, the morphological characteristics of the isolates, such as colony color, shape and size of conidium, conidiophore, sclerotia, and their distribution on the culture medium, were obtained. Additionally, the G3PDH gene region was amplified and sequenced using PCR. Based on the combined morphological and molecular characteristics the species was identified as Botrytis cinerea. The radial growth of isolates was then investigated at 4, 10, 25 and 30 (±1) ℃ on PDA and Hayward cultivar kiwifruit. To study the radial growth of isolates, 6 mm diameter disks from 6-day-old cultures of isolates were placed on PDA medium at the mentioned temperatures and in dark conditions (in three replicates). Additionally, after washing and cleaning the surface of the fruits, they were surface sterilized, by immersion them in sodium hypochlorite solution (5% commercial solution available in the market) for 10 minutes, followed by washing with sterile distilled water for 4 minutes (twice) and air drying on sterile filter paper. A hole with a diameter of 6 mm and a depth of 3 mm was made with a sterile cotton swab in the flesh of the fruit and at the fruit’s styler end. Six mm diameter disks from 6-day-old cultures were placed in the holes created in the fruits. The inoculated fruits were placed at the desired temperatures and in dark conditions. The diameter of the isolates was measured daily until it reached the edge of the dishes and on the kiwifruit for three weeks. The examination of the average radial growth of the isolates at different temperatures showed that the average radial growth of all isolates on PDA medium was greater than on the kiwi fruit. The highest rate of vegetative growth was observed on PDA at 25 ℃.