鲜切西兰花贮藏期病原菌分离鉴定及植物精油对其抑制效果

Isolation and Identification of Pathogens from Fresh-Cut Broccoli during Storage and Their Inhibition by Plant Essential Oils

以‘冬至绿’西兰花为试材,分离、纯化并鉴定鲜切西兰花贮藏期病原菌,筛选出抑制病原菌效果较好的植物精油。通过分离、纯化及致病性实验得到病原真菌菌株AB01,以病原菌内源转录间隔区序列进行进化树分析,鉴定该病原菌为链格孢菌(Alternaria alternata)。选用肉桂、茴香、牛至、丁香、百里香和香茅6种精油对AB01进行抑菌性实验,通过体外抑菌和活体抑菌筛选出最优的精油种类及含量。结果发现,肉桂精油对AB01的抑菌效果最好,其最低抑菌浓度和最低杀菌浓度分别为0.05μL/mL和0.15μL/mL,其次是茴香和牛至精油。0.15μL/mL肉桂精油用于鲜切西兰花可有效降低花球黄花率和切面褐变率。

This study was intended to isolate, purify, and identify the pathogens that can cause etiolation and browning in fresh-cut broccoli during storage and to screen plant essential oils for their effectiveness in controlling these pathogenic isolates. A pathogenic fungal strain （AB01） was obtained. According to the phylogenetic tree constructed based on the internal transcribed spacer （ITS） region in it, AB01 was identified as Alternaria alternata. The inhibitory effects of six plant essential oils including cinnamon, fennel, bovine, clove, thyme and citronella oils against AB01 were tested both in vitro and in vivo in order to select the optimum oil species and concentration. The results showed that cinnamon essential oil possessed the best antimicrobial effect with a minimum inhibitory concentration （MIC） of 0.05 μL/mL and minimum fungicidal concentration （MFC） of 0.15 μL/mL, followed by fennel and oregano oils. Cinnamon essential oil at 0.15 μL/mL could effectively reduce both etiolation and browning in fresh-cut broccoli.