RESUMO
We determined whether heat and chemical treatments could reduce the decay of kiwifruit caused by Botrytis cinerea during postharvest storage. Kiwifruits were treated with 5 g/L (w/v) potassium sorbate (PS), with a 48 °C hot water treatment (HT), and with a combined treatment (HT + PS). Mycelial growth of B. cinerea and the postharvest quality of 'XuXiang' kiwifruits were evaluated. HT + PS significantly inhibited mycelial growth, germ tube growth, and spore germination of B. cinerea. This treatment also reduced the incidence of gray mold in kiwifruit postharvest, and enhanced activities of defense-related enzymes in kiwifruit tissues. Compared with the control, all treatments resulted in lower malondialdehyde (MDA) contents and higher total phenolic contents in kiwifruits. HT + PS also increased the activities of chitinase and ß-1,3-glucanase and the transcript levels of their encoding genes. HT + PS can improve kiwifruit quality and reduce decay during postharvest storage.