Difference of resistance to postharvest blue mold between Hongyang and Qihong kiwifruits

Abstract This study aimed to reveal the physiological mechanism of resistance to postharvest blue mold of kiwifruit. Hongyang and Qihong kiwifruits were inoculated with Penicillium expansum ( P. expansum ) and stored at low temperature (0 ± 1 °C). The disease incidence and lesion diameter, activities of defense-related enzymes, and contents of defense-related substance of Hongyang and Qihong kiwifruits were also compared, combined with the observation of fruit pericarp structure by scanning electron microscopy. Results showed that the disease resistance of Hongyang was stronger than that of Qihong with late onset, low incidence, and small lesion diameter. And Hongyang kiwifruit showed a high biochemical resistance after inoculation with P. expansum . The epidermis structure of Hongyang kiwifruit had typical disease resistance characteristics with a dense epidermis structure, orderly cell arrangement, and less obvious microcracks. The strong biochemical resistance, dense, and complete epidermis structure of Hongyang fundamentally guarantee its strong resistance to diseases.