First report of <i>Alternaria alternata</i> causing flower blight on <i>Camellia sinensis</i> in Hefei, China

Flowers are an essential organ for sexual reproduction of higher plants. Severe lesions along with flower blight on tea (Camellia sinensis) plants were observed in the experimental tea plantation located in Hefei (China). The pathogens isolated from diseased flowers matched the morphological peculiarity of Alternaria alternata. The species characteristics of A. alternata were further confirmed by both pathogenicity tests and multi-gene phylogenetic analyses by using internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and beta-tubulin (TUB). The combined phylogeny analysis using sequences derived from the ITS, GAPDH and TUB showed that the isolated pathogens belong to the genus Alternaria. Pathogenicity tests conducted on healthy tea flowers and leaves manifested typical symptoms of flower blight while weaker symptoms of leaf spot, demonstrating the A. alternata isolates were the causal agents of flower blight disease on tea plants. This fungus is first reported as a pathogen causing flower blight on C. sinensis in this study.