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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。
In recent years, Shanxi jujube occurred a serious disease of the fruit, the performance of the top of the fruit or fruit shoulder formation of red-brown spots. In this study, the bottle of jujube for the material, the bacteria were isolated. Through indoor and field pathogenicity determination and artificial inoculation, the bacteria were isolated again, and the fungal strain CN535 was proved to be the pathogen of the disease. The diameter of colonies on PDA for 7d was 69.2-73.5mm, the mycelia and aerial mycelia were well developed on the PDA, with obvious gray and dark green concentric pattern. Conidiophores were single or short, with vertical and horizontal (22.5 ~ 40.0) μm × (8.0 ~ 13.5) μm, which is typical of the genus Alternaria. The results of rDNA ITS sequence analysis showed that this strain shared 100% homology with A.alternata, A. tenuissima, A.longipes, A.mali and A. citri. Two pairs of Alternaria alternata primers AAF2 / AAR3 and Aalt-F / Aalt-R were used to amplify the corresponding 341 and 450 bp fragments, respectively. According to the morphological characteristics and molecular analysis, A. pathogen (Fries) Keissler was identified.