First Record of Alternaria Tenuissima Causing Aloe Barbadensis Leaf Blight and Leaf Spot Disease in Beijing, China

In 2020, Alternaria leaf blight and spot disease was first observed on Aloe barbadensis in Beijing, China. Samples of diseased leaves of A. barbadensis showing blight and spot symptoms (dark brown necrotic, sunken, and emerged lesions) were collected and identified as Alternaria isolates. The fungal colony was olive green, while conidia were brown, obclavate and measured from 13.4 to 34.2 × 7.5–11.8 μm (length × width) on average. Genomic DNA extraction was performed by multi-locus sequence analysis and the pathogen was identified as Alternaria tenuissima. The pathogenicity test confirmed A. tenuissima's ability to infect A. barbadensis and cause typical leaf blight and spot symptoms, with subsequent re-isolation. This is the first report of leaf blight and leaf spot on A. barbadensis caused by A. tenuissima in Beijing, China. Due to the medicinal importance of A. barbadensis worldwide, studying A. tenuissima induced leaf blight and spot is imperative.