对怀黄菊(Chrysanthemum morifolium Ramat.‘Huaihuang’)上发生的一种叶片变黑枯死的主要病害进行了病原分离和鉴定,通过形态观察、产孢表型分析、致病力检测和r DNA-ITS序列分析,初步确定该病是由链格孢属(Alternaria)的交链孢菌(Alternaria sp.)引起的怀黄菊黑斑病。从发病植株中分离纯化得到2个致病菌株A1和A2;PDA培养基上的2个致病菌株菌落质地、颜色、边缘整齐度等特征存在一定差异,显微镜下产孢表型也存在差异,但致病力没有差异,其r DNA-ITS序列一致性达100%,序列已在Gen Bank上登录,登录号为KF688111。 The pathogen was isolated and identified as one of the main diseases of Chrysanthemum morifolium Ramat. ’Huaihuang’ which died of black-and-white death. Morphological observation, sporulation analysis, pathogenicity test and r DNA-ITS Sequence analysis showed that the disease was initially identified as Alternaria sp. Caused by Alternaria sp. Two pathogenic strains A1 and A2 were isolated and purified from diseased plants. There were some differences in colony texture, color, edge uniformity among the two pathogens on PDA medium. There were also differences in sporulation phenotype under microscope, However, there was no difference in pathogenicity. The sequence identity of rDNA-ITS was 100%. The sequence was registered on Gen Bank under accession number KF688111.