Effect of Thymol and Linalool Fumigation on Postharvest Diseases of Table Grapes

Several postharvest diseases of table grapes (Vitis vinifera) occur during storage, and gray mold rot is a particularly severe disease because the causal agent, Botrytis cinerea, grows at temperatures as low as 0degrees C. Other postharvest diseases, such as those caused by Penicillium spp. and Aspergillus spp., also often lead to deterioration in the quality of table grapes after harvest. The use of plant essential oils such as thymol and linalool, to reduce postharvest diseases in several kinds of fruits, including table grapes and oranges, has received much attention in European countries. However, to the best of our knowledge there has been no report of the use of thymol fumigation to control gray mold in table grapes in Korea. Thymol (30 microg/mL) and linalool (120 microg/mL) significantly inhibited mycelial growth and conidia germination of B. cinerea. The occurrence rate of gray mold rot of B. cinerea and other unknown fungi was significantly reduced by fumigation with 30 microg/mL thymol in several table grape cultivars, such as Campbell early, Muscat Bailey A, Sheridan, and Geobong. In this study, fumigation with 30 microg/mL thymol, had no influence on the sugar content and hardness of grapes, but reduced fungal infection significantly. This suggests that 30 microg/mL thymol could be utilized to reduce deterioration of grapes due to gray mold and other fungal infections during long-term storage.

Ultraviolet Mutation Breeding Aspect of the Biological Control of Postharvest Diseases by Kloeckera apiculata in Citrus Fruit / 微生物学通报

A series of experiments were conducted to study the mutation of Kloechera apiculata by many kinds of treatments such as UV and UV+LiCl.The optimal dosage disposal was determined:15 W 30 cm under Ultraviolet irradiation for 20 s,UV+LiCl under Ultraviolet irradiation for 20 s and added LiCl 0.3% (w/v).One strain(UV20-13)which had obvious physiological characteristic was obtained.the incidence of blue and green mold of citrus was reduced by 25.56%and 10.00%in vivo experiment after 7 days respectively. The strain UV20-13 was tested by the experiments of subculture and dynamic growth,and the results showed that the strain UV20-13 was better than K.apiculata in the growth characteristics,and it did not appear retrogression,reversion mutation ect after subculturing 10 generations.Therefore the strain UV20-13 had genetic stability.