一种快速分离牡丹黄斑病菌的选择性培养基

采用传统的组织分离法分离牡丹黄斑病菌Phyllosticta commonsii存在费时、费力且成功率低等问题，为提高分离效率，本研究利用杀菌剂抑菌谱的不同，以加入50 μg/mL硫酸链霉素的马铃薯蔗糖琼脂培养基为基础培养基，通过向该基础培养基中加入一定量的多菌灵、乙膦铝及代森锰锌，制备了一种在非无菌条件下即可分离牡丹黄斑病菌的选择性培养基。正交试验表明:该选择性培养基中多菌灵、乙膦铝及代森锰锌的适宜质量浓度分别为0.5、100~200及3.125~12.5 μg/mL。所制备的选择性培养基可有效抑制3种常见污染真菌——变幻青霉Penicillium variabile、黑曲霉Aspergillus niger和细极链格孢Alternaria tenuissima的生长，但对牡丹黄斑病菌的生长影响较小，可用于牡丹黄斑病菌的分离。

A selective medium to isolate Phyllosticta commonsii rapidly from diseased peony leaves

Traditional pathogen isolation method was time consuming, laborious and with low success rate. In order to improve the isolation efficiency, a selective medium was developed for the isolation of Phyllosticta commonsii under non-sterile environmental conditions. PSA containing streptomycin sulfate (50 μg/mL) was used as the basal medium. Carbendazim, fosetyl-aluminum and mancozeb with different concentrations were employed as additives. Results from orthogonal experiments showed that the suitable concentrations of carbendazim, fosetyl-aluminum and mancozeb in selective medium were 0.5 μg/mL, 100-200 μg/mL and 3.125-12.5 μg/mL, respectively. Although the selective medium can effectively inhibit the growth of three common interferefering fungi, Penicillium variabile, Aspergillus niger, and Alternaria tenuissima, it has little effect on the growth of macular pathogen, which implied that it could be used to isolate P. commonsii from the diseased blades of peony.