植物精油抑制炭疽菌及对枇杷采后炭疽病与品质的影响

为探讨植物精油对枇杷采后炭疽菌抑制的效果及其机理,分别用丁香酚、柠檬醛和香芹酚对尖孢炭疽菌进行体外处理,筛选出丁香酚为最优抑制剂并研究了其对尖孢炭疽菌外渗率、核酸泄漏及蛋白质的影响。以枇杷为供试材料,接种尖孢炭疽菌后分别用0.5、1.0、2.5、5.0μL/L的丁香酚熏蒸处理,统计病害发生率及病斑直径,并研究了丁香酚对枇杷品质的影响。结果表明:在体外实验中,3种供试精油对尖孢炭疽菌均有明显的抑制作用,48μL/L丁香酚可以完全抑制尖孢炭疽菌的生长,且在一定程度上造成了菌内细胞内容物的渗出。在丁香酚对枇杷果实采后炭疽病抑制效果实验中发现,贮藏6 d时,1μL/L丁香酚处理组病斑直径及病害发生率显著低于对照组,病斑直径仅为6.41 mm,病害发生率为66.67%。丁香酚对枇杷品质影响方面,其能够显著抑制采后枇杷质量损失率的上升及VC含量下降(P0.05),但对枇杷的颜色、硬度、可溶性固形物及可滴定酸等品质指标影响不显著(P0.05)。

Inhibitory Effect of Plant Essential Oils on Colletorichum acutatum and Postharvest Anthracnose and Quality of Loquat Fruits

This experiment was conducted to study the inhibitory effect of three plant essential oils (eugenol, citral and carvacrol) on Colletorichum acutatum by means of in vitro fumigation and the effect of the strongest inhibitor, eugenol, on the ratio of exosmosis, intracellular nucleic acid and protein contents of C. acutatum. After wounding and artificial inoculation with C. acutatum, loquat fruits underwent eugenol fumigation at 0.5, 1.0, 2.5 and 5.0 μL/L. Disease incidence and lesion diameter were recorded and the effect of this treatment on the fruit quality was also studied. Results showed that all three essential oils demonstrates inhibitory activities in vitro against C. acutatum. Eugenol could inhibit the growth of C. acutatum completely at a concentration of 48 μL/L and cause the leakage of cytoplasm. Compared with the control group, 1 μL/L eugenol could significantly reduce anthracnose incidence to 66.67% and average lesion diameter to 6.41 mm after 6-day storage. Moreover, percentage water loss and vitamin C loss were significantly inhibited (P < 0.05), while no significant changes were observed in firmness, color, soluble solid content, titratable acid or ascorbic acid in loquat fruits (P > 0.05).