Abstract: The postharvest grape berries (Vitis vinifera L. 'Kyoho') were used to investigate effects of the nutrition, pH and physiological condition of grape，and environmental temperature on the conidia development and the hypha growth of Botrytis cinerea. The results indicated that the nutrition and pH value of the grape extract were very suitable for the conidia germination and hypha growth of B.cinerea. Compared with other postharvest pathogens, such as Alternaria alternata, Fusarium sp., Cladosporium sp. and Trichotecium roseum, B.cinerea had significant growth predominance on the grape extract medium. The spores of B. cinerea germinated between 0～35 ℃ when incubated in the medium of grape juice at pH 3.46. The optimal germination temperature of spores was 15～24 ℃ and the germination rate of B. cinerea spores was 8.7% even cultured at 0 ℃ for 48 h. The germination rate at pH 4 was above 90% when cultured at 4 ℃ for 72 h and was higher than at pH 5-7. This suggests that the spore germination of B.cinerea need low pH at low temperature. The invasiveness of B. cinerea enhanced with the extension of storage. B. cinerea reduced the POD and chitinase activity of the host during the infection process. The results suggest that B.cinerea is more compatible with postharvest grape berries than A.alternata.

Key words: grape berry, Botrytis cinerea, postharvest disease, nutrition, pH, pathogenesis-related protein