【摘要】 近几年来,山西红枣发生了1种严重的果实病害,症状表现为果顶或果肩部位形成红褐色的病斑。本研究以壶瓶枣为材料,对病菌进行分离。通过室内和田间致病性测定以及人工接种后再分离病菌,证明编号为CN535的真菌菌株为该病的致病菌。该病菌在PDA上7d菌落直径达69.2～73.5mm,基内菌丝和气生菌丝均发达,具明显的浅灰与墨绿色的同心轮纹;分生孢子单生或短链生,具纵横隔膜和短喙,大小为(22.5～40.0)μm×(8.0～13.5)μm,为典型的Alternaria属真菌特征。其rDNAITS序列分析结果表明该菌与A.alternata、A.tenuissima、A.longipes、A.mali和A.citri的同源性均为100%。用2对链格孢菌的专用引物AAF2/AAR3和Aalt-F/Aalt-R分别扩增出相对应的341和450bp的片段。综合形态特征和分子分析结果,确定壶瓶枣褐斑病的病原菌为A.alternata(Fries)Keissler。更多还原

【Abstract】 One disease on jujube fruit was reported in Shanxi Province in recent years. The typical symptom was brown spots formed on the top or shoulder of fruits. The suspected pathogen was isolated from diseased fruits. After pathogenicity tests in lab and field and re-isolation of the pathogen, the strain CN535 was determined to be responsible for the disease. CN535 colony on PAD was 69.2-73.5 mm in diameter, with concentric rings in light-gray and dark-green color in seven days. The conidia, (22.5-40.0) μm×(8.0-13.5) μm, were obclavate and obpyriform, ellipsoidal in form and formed singly or in short chains, with a conical or cylindrical beak and transverse, longitudinal or oblique septa; they were showing the typical morphology of the genus Alternaria. Its rDNA ITS sequence had 100% similarity with those of A. alternata, A. tenuissima, A. longipes, A. mali and A. citri searched in GenBank. The species specific fragments of 341 bp and 450 bp were amplified with two pairs of sensitive primers AAF2/AAR3 and Aalt-F/Aalt-R. Based on the morphological characteristics and rDNA molecular analysis, the pathogen was finally identified as A. alternata (Fries) Keissler.更多还原