First report of stem rot caused by Coniothyrium fuckelii on Morus alba in China.
In spring 2015 and 2016, stem rot symptoms were observed on mulberry (Morus alba cv. Hongguo No. 2) in a 10-ha commercial farm in Luoyang City, Henan Province, China, where approximately 50% of the plants were found diseased. Symptoms of the disease initially appeared on the stems as light brown lesions that gradually became brown. The lesions eventually depressed and expanded to a long ellipse, resulting in yellowing and wilting of the foliage in 7 days. A fungus was consistently isolated from the stem lesions on potato dextrose agar. Based on morphological characteristics, DNA sequence analysis of the internal transcribed spacer and pathogenicity tests, the causal agent was identified as C. fuckelii. This is thought to be the first report of C. fuckelii infecting M. alba in China, which may have an important economic impact on M. alba.