“贵长”猕猴桃致病菌的鉴定与天然抑菌剂筛选

Identification of Pathogenic Fungi and Screening of Natural Antifungal Agents from ‘Guichang’ Kiwifruit

摘要:

对“贵长”猕猴桃在贮藏过程中几种致病菌进行了分离纯化，并研究了肉桂、丁香、薄荷、花椒等天然精油的抑菌效果。通过致病菌的鉴定，确定了致病菌的种类；通过抑菌试验，研究了不同精油的抑菌效果。鉴定结果表明：“贵长”猕猴桃中分离出四种不同的致病真菌，分别为黑曲霉菌（Aspergillus niger）、葡萄座腔菌（Botryosphaeria dothidea）、可可毛色二胞（Lasiodiplodia pseudotheobromae）、黄曲霉菌（Aspergillus flavus），四种真菌对“贵长”猕猴桃均具有很强的致病性。抑菌试验表明：肉桂、丁香、薄荷3种精油在0.25%的体积分数下具有良好的抑菌效果，对四种致病菌抑制率达到78.00%以上，而复合精油具有更低的抑菌浓度和更广的抑菌范围。由体积分数0.12%的肉桂和薄荷配制的复合精油在对4种致病菌抑菌率分别达到了100.00%、99.43%、98.35%、95.01%，其中薄荷精油能够显著增强复合精油的抑菌效果。通过天然精油的复配能有效抑制“贵长”猕猴桃贮藏过程中几种常见致病菌的生长，实现对有害微生物的防控。

Abstract:

Several pathogenic fungi of the ‘Guichang’ kiwifruit were isolated and purified during storage, and the antifungal effects of natural essential oils such as cinnamon, clove, mint, and Sichuan peppercorn essential oils were examined. Different types of pathogenic fungi were identified, and the antifungal effects of different essential oils were determined through antifungal tests. Four pathogenic fungi were isolated from the kiwifruit, namely Aspergillus niger, Botryosphaeria dothidea, Lasiodiplodia pseudotheobromae, and Aspergillus flavus. All four fungi were highly pathogenic to the kiwifruit. The results of the antifungal test showed that the essential oils of cinnamon, clove, and mint had good antifungal effect at a concentration of 0.25%. The inhibition rate against the four pathogenic fungi reached more than 78.00%, whereas the compound essential oils had lower antibacterial activity and higher antifungal activity. Specifically, the compound essential oil prepared using 0.12% cinnamon and mint had antifungal rates of 100.00%, 99.43%, 98.35%, and 95.01% against the four pathogenic fungi respectively. In addition, the mint essential oil significantly enhanced the antifungal effect of the compound essential oil. Thus, the combination of natural essential oils can effectively inhibit the growth of several common pathogenic fungi during the storage of the 'Guichang' kiwifruit. These results highlight the need for prevention and control measures against harmful microorganisms.