بررسی تنوع ریخت شناختی و توان بیماریزایی تعدادی از جدایه های Botrytis sp. از کیوی رقم هایوارد

Annually a large amount of kiwifruit is destroyed due to fungal rots in the storages. The most important and dangerous kiwifruit disease in storages is gray mold that its causal agent is various species of Botrytis, especially Botrytis cinerea. In this study, suspicious and infected fruits by gray mold collected from various storages and orchards and transferred to laboratory. After examining the infected fruits by binocular and seeing the hyphae, the specimens were cultured directly on PDA medium containing sulfate streptomycin. The cultures were incubated for 7-10 days in the dark at 25 ℃. After growing of Botrytis colonies and initial diagnosis, the colonies were purified by hyphal tip method. Isolates identified by available articles and examining morphological characteristics such as color and appearance of colony, shape of conidia and conidiophores, color and shape and distribution of sclerotia over the medium and characteristics such as length and width of conidia, sclerotia dimensions and conidiophore length. Based on morphological characteristics, five isolates identified as Botrytis cinerea, although they were showing morphological diversity. For evaluating the pathogenicity of the five studied isolates, Kiwifruits were surface sterilized with 5% commercial sodium hypochlorite solution and wounds were made in the skin of the fruits with cork borer. Then, disks of 7 days old isolates colonies were located at the site of wounds and wounds caused by the removal of pedicles. The fruits were placed in the dark at 25℃ in incubator and the diameter of the grown colonies at the wound sites was measured in three steps. Based on the results, isolates were variable in pathogenicity and one of the isolates resulted in high disease severity.