丁香精油对甜樱桃采后优势致腐真菌的控制及其抑菌机理

为探明植物精油对甜樱桃采后优势致病菌的抑菌效力及抑菌机理,以山东泰安地区主栽品种红灯为试验材料,从自然腐烂的甜樱桃果实上分离纯化优势致病菌,采用形态学方法并结合ITS序列法进行鉴定,选用丁香精油从体外熏蒸和接触2种作用方式研究其对主要病原真菌的抑菌效果。结果表明,甜樱桃采后的3种主要致腐真菌分别为灰葡萄孢菌(Botrytis cinerea)、链格孢菌(Alternaria alternata)和胶孢炭疽菌(Colletotrichum gloeosporioides);体外抑菌试验表明,一定浓度的丁香精油能显著抑制3种致病菌的菌丝生长和孢子萌发,熏蒸处理较接触效果更好,对B. cinerea、 A. alternata和C. gloeosporioides的最小抑菌浓度(MIC)分别为120、100和100 μL·L^-1;试验还表明丁香精油破坏了菌丝形态,其抑菌机理可能与精油疏水性造成的微生物膜系统结构破坏、及胞内主要内容物流失有关。综上所述,丁香精油作为甜樱桃贮藏前的熏蒸剂具有较好的应用潜力。

Antifungal Activity and Possible Mechanism of Clove Essential Oil on Dominant Pathogens of Postharvest Sweet Cherries

The paper aimed to reveal the antifungal activity and possible mechanism of plant essential oil on dominant pathogens of postharvest sweet cherries. Hongdeng, the main varietiy in Taian, Shandong Province, was chosen as the raw material, traditional morphological identification method combined ITS analysis was performed to separate dominant pathogens from rotten sweet cherries, and antifungal activity of clove essential oil on three pathogenic fungal strains was assessed by in vitro fumigation and contact. The results showed that these strains were identified as Botrytis cinerea, Alternaria alternate and Colletotrichum gloeosporioides. Clove oil at certain concentrations exhibited obvious antifungal effects by inhibiting mycelial growth and spore germination of the three strains, and fumigation was better than contact. For B. cinerea, A. alternate and C. gloeosporioides, the minimal inhibitory concentrations (MIC) of clove oil in air phase were 120, 100 and 100 μL·L^-1 in vitro testing, respectively. Moreover, the possible mechanisms of fumgitoxic action were related to the hydrophobicity of essential oils which enabled them to disrupt membrane structure of microorganism, and lead to loss of cell contents. In conclusion, clove essential oil was proved to be a promising candidate as effective antifungal agent for postharvest decay of sweet cherries.