Abstract Sour rot is caused by Geotrichum citri-aurantii and is one of the devastating diseases in citrus fruit. This disease is difficult to control because of the lack of effective fungicides. In this study, cinnamaldehyde, a common food preservative, was evaluated to control postharvest sour rot in citrus fruit through in vivo and in vitro experiments. Results showed that cinnamaldehyde with a minimum inhibitory concentration and fungicidal concentration of 0.50 mL L−1 dose-dependently inhibited the mycelial growth of G. citri-aurantii. The application of wax with cinnamaldehyde (WCA; 0.50, 1.0, and 2.0 mL L−1) significantly reduced the incidence of sour rot on citrus fruit inoculated with G. citri-aurantii during storage. After 8 d of storage, the decay incidences in the fruit treated with WCA (0.50, 1.0, and 2.0 mL L−1) were only 80%, 77% and 50%, respectively. By contrast, the decay incidence in the control fruit was 100%. In addition, WCA treatment increased the activities of superoxide dismutase (SOD), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL), but did not affect the activities of catalase (CAT) and peroxidase (POD), and the total phenol content. Our results suggested that WCA might induce defense responses against sour rot in citrus fruit.

中文翻译：

---

肉桂醛抑制柑橘地霉菌丝生长并诱导柑橘类水果酸腐病的防御反应

摘要 酸腐病是由枳壳霉引起的，是柑橘类水果的毁灭性病害之一。由于缺乏有效的杀菌剂，这种病害很难控制。在这项研究中，肉桂醛是一种常见的食品防腐剂，通过体内和体外实验评估了对柑橘类水果采后酸腐病的控制。结果表明，肉桂醛的最低抑菌浓度和杀菌浓度为 0.50 mL L-1，剂量依赖性地抑制了枳壳 G. citri-aurantii 的菌丝生长。蜡与肉桂醛（WCA；0.50、1.0 和 2.0 mL L-1）的应用显着降低了在储存期间接种了 G. citri-aurantii 的柑橘类水果的酸腐病发生率。贮藏 8 天后，WCA（0.50、1.0 和 2.0 mL L−1）处理的果实腐烂率仅为 80%，分别为 77% 和 50%。相比之下，对照水果的腐烂发生率为 100%。此外，WCA处理增加了超氧化物歧化酶（SOD）、多酚氧化酶（PPO）和苯丙氨酸解氨酶（PAL）的活性，但不影响过氧化氢酶（CAT）和过氧化物酶（POD）的活性，以及​​总酚含量. 我们的结果表明，WCA 可能会诱导柑橘类水果对酸腐病的防御反应。