Species of Associated with Citrus Branch Diseases in China

Citrus is an important and widely cultivated fruit crop in South China. Although the species of fungal diseases of leaves and fruits have been extensively studied, the causal organisms of branch diseases remain poorly known in China. Species of are known as important fungal pathogens causing branch diseases on citrus in the USA and Europe. To determine the diversity of species associated with citrus branch diseases in China, surveys were conducted in the major citrus-producing areas from 2017 to 2020. Diseased tissues were collected from twigs, branches and trunks with a range of symptoms including cankers, cracking, dieback and gummosis. Based on morphological characteristics and phylogenetic comparison of the DNA sequences of the internal transcribed spacer region (ITS), the translation elongation factor 1-alpha gene (), the β-tubulin gene () and the DNA-directed RNA polymerase II second largest subunit (), 111 isolates from nine provinces were identified as 18 species of , including , , , , , , , , , , , , and six previously undescribed species, namely , , , , and spp. nov. (28.8 %) was the most abundant species, followed by (23.4 %), which was the most widely distributed species on citrus, occurring in six of the nine provinces sampled. Pathogenicity tests indicated that all 18 species of obtained from diseased citrus tissues in this study were pathogenic to the tested shoots , while not all species are pathogenic to the tested Cocktail grapefruit ( × ) shoots . In addition, was the most aggressive genus both and . This is the first study to identify species related to citrus branch diseases in China and the results provide a theoretical basis for the implementation of prevention and control measures. : Xiao XE, Wang W, Crous PW, et al. 2021. Species of Botryosphaeriaceae associated with citrus branch diseases in China. Persoonia 47: 106-135. https://doi.org/10.3767/persoonia.2021.47.03.