Department of Agriculture, Food and Environment (Di3A), University of Catania, via S. Sofia 100, 95123, Catania, Italy.
Department of Agriculture, Food and Environment (Di3A), University of Catania, via S. Sofia 100, 95123, Catania, Italy.
Food Microbiol. 2020 Dec;92:103583. doi: 10.1016/j.fm.2020.103583. Epub 2020 Jun 27.
Combined use of biocontrol agents and plant extracts can be considered a viable and promising strategy for protecting plant tissues with different synergistic mechanisms of action that improve the antimicrobial activity of the mixtures. Treatments of citrus fruits with Wickerhamomyces anomalus BS91 have been previously reported as effective measures to reduce the incidence of green mold caused by Penicillium digitatum. On the opposite, the knowledge of the antifungal activity of cultivated cardoon (Cynara cardunculus L. var. altilis DC.) leaf extract, vegetable widespread in some Mediterranean areas, is still very limited. In this study, experimental trials were conducted to evaluate the effectiveness in vitro of leaf aqueous, methanolic and ethanolic extracts of C. cardunculus against seven fungal pathogens responsible for considerable food losses in the postharvest stage. In addition, biocontrol yeast W. anomalus BS91 and the three C. cardunculus extracts were tested in vivo both as a single treatment and in mixture, against Penicillium digitatum on 'Tarocco' oranges and 'Femminello' lemons. The combination of W. anomalus BS91 and leaf ethanolic extract reduced with the highest efficacy the incidence and severity of green mold on orange and lemon fruits with respect to the control, and was more effective than treatment with antagonistic yeast or leaf extracts applied alone. Incidence and severity of citrus decay were more consistently reduced when mixtures were applied 24 h before the inoculation of the pathogen, thus suggesting the relevance of preventive treatments. The mixtures of antagonistic W. anomalus BS91 and ethanolic leaf extract were more effective in controlling green mold decay on oranges than on lemons. These results indicate that biocontrol agents and leaf extracts, used in appropriate combination, can provide a stronger protection than when used singularly. However, compatibility between microbial antagonist and antimicrobial extract should be preliminary verified.
联合使用生物防治剂和植物提取物可以被认为是一种可行且有前途的策略，可用于保护具有不同协同作用机制的植物组织，从而提高混合物的抗菌活性。先前有报道称，用异常威克汉姆酵母 BS91 处理柑橘类水果是减少由指状青霉引起的青霉病发病率的有效措施。相反，关于栽培的蓟（Cynara cardunculus L. var. altilis DC.）叶提取物的抗真菌活性的知识仍然非常有限，蓟是一种在一些地中海地区广泛种植的蔬菜。在这项研究中，进行了实验性试验，以评估 C. cardunculus 叶的水、甲醇和乙醇提取物对七种在采后阶段导致大量损失的真菌病原体的体外有效性。此外，将生物防治酵母异常威克汉姆酵母 BS91 和三种 C. cardunculus 提取物单独处理和混合处理，用于防治‘Tarocco’甜橙和‘Femminello’柠檬上的指状青霉。与对照相比，异常威克汉姆酵母 BS91 和叶乙醇提取物的组合以最高的功效降低了甜橙和柠檬果实上青霉病的发病率和严重程度，并且比单独使用拮抗菌酵母或叶提取物处理更有效。当在接种病原体前 24 小时施用混合物时，柑橘腐烂的发病率和严重程度更一致地降低，这表明预防处理的相关性。拮抗异常威克汉姆酵母 BS91 和乙醇叶提取物的混合物在控制甜橙上的青霉病腐烂方面比在柠檬上更有效。这些结果表明，生物防治剂和叶提取物以适当的组合使用可以提供比单独使用更强的保护。然而，微生物拮抗剂和抗菌提取物之间的兼容性应该预先验证。
