西葫芦弯孢叶枯病病原菌Curvularia spicifera的鉴定

In June 2021, a new disease with necrotic symptoms affecting the leaves of Cucurbita pepo was observed in Yan'an city, Shaanxi province, China. Disease samples were collected and fifteen isolates (cucup1-cucup15) were obtained by tissue isolation and single spore purification methods. According to the morphological features and analysis of rDNA internal transcribed spacer (ITS) and RNA polymerase II second largest subunit (RPB2) sequences, the fungal isolates were identified as Curvularia spicifera, a new pathogen on C. pepo. The pathogenicity assay confirmed that C. spicifera was the pathogen causing this disease. This is the first record of leaf necrotic disease caused by C. spicifera in China.     

马铃薯鲜粉污染菌的分离鉴定及抑制物筛选

为探究引起马铃薯鲜粉贮藏期污染变质的细菌并找到合适的抑菌物,以延长其保鲜期,采用平板划线分离法对污染细菌进行分离纯化并通过形态学特征、理化性质及16S rDNA序列等对其进行初步鉴定,并通过滤纸片法添加双乙酸钠溶液、山梨酸钾溶液、八角茴香精油粗提物、柑橘精油粗提物4种抑菌物对其进行抑菌试验。结果表明,从污染的马铃薯鲜粉中初步分离出4种菌株,其中1株菌属为短小杆菌属(Curtobacterium);4种抑菌物对短小杆菌属、埃希氏菌属、芽孢杆菌属3种易染菌均有一定的抑菌效果,且在相同浓度下双乙酸钠溶液抑菌效果最好,可作为马铃薯鲜粉易染菌候选抑制剂。