Diversity of Monochaetia Species from Fagaceous Leaf Spots in China and Pathogenicity for Chinese Chestnut

Ning Jiang; Hermann Voglmayr; Han Xue; Chun-Gen Piao; Yong Li

doi:10.1128/spectrum.00042-23

Microbiology Spectrum (Jun 2023)

Diversity of Monochaetia Species from Fagaceous Leaf Spots in China and Pathogenicity for Chinese Chestnut

Ning Jiang,
Hermann Voglmayr,
Han Xue,
Chun-Gen Piao,
Yong Li

Affiliations

Ning Jiang: Key Laboratory of Biodiversity Conservation of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
Hermann Voglmayr: Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
Han Xue: Key Laboratory of Biodiversity Conservation of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
Chun-Gen Piao: Key Laboratory of Biodiversity Conservation of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
Yong Li: Key Laboratory of Biodiversity Conservation of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China

DOI: https://doi.org/10.1128/spectrum.00042-23
Journal volume & issue: Vol. 11, no. 3

Abstract

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ABSTRACT Pestalotioid fungi have been frequently studied with respect to their morphology, molecular phylogeny, and pathogenicity. Monochaetia is a pestalotioid genus that is morphologically characterized by 5-celled conidia with single apical and basal appendages. In the present study, fungal isolates were obtained from diseased leaves of Fagaceae hosts in China in 2016 to 2021 and identified based on morphology and phylogenetic analyses of the 5.8S nuclear ribosomal DNA gene with the two flanking internal transcribed spacer (ITS) regions, the nuclear ribosomal large subunit (LSU) region, the translation elongation factor 1-α (tef1) gene, and the β-tubulin (tub2) gene. As a result, five new species are proposed here, namely, Monochaetia hanzhongensis, Monochaetia lithocarpi, Monochaetia lithocarpicola, Monochaetia quercicola, and Monochaetia shaanxiensis. In addition, pathogenicity tests for these five species and Monochaetia castaneae from Castanea mollissima were conducted with detached leaves of Chinese chestnut. Results demonstrated that only M. castaneae successfully infected the host C. mollissima and caused brown lesions. IMPORTANCE Monochaetia is a pestalotioid genus, with members that are commonly known as leaf pathogens or saprobes; some strains were isolated from air, in which case their natural substrate is so far unknown. Fagaceae represents an ecologically and economically important plant family that is widely distributed in the Northern Hemisphere, including an important tree crop species, Castanea mollissima, which is widely cultivated in China. In the present study, diseased leaves of Fagaceae in China were investigated, and five new Monochaetia species were introduced based on morphology and phylogeny of combined ITS, LSU, tef1, and tub2 loci. Additionally, six species of Monochaetia were inoculated onto healthy leaves of the crop host Castanea mollissima to test their pathogenicity. The present study provides significant data on the species diversity, taxonomy, and host range of Monochaetia and enhances our understanding of leaf diseases of Fagaceae hosts.

Published in Microbiology Spectrum

ISSN: 2165-0497 (Online)
Publisher: American Society for Microbiology
Country of publisher: United States
LCC subjects: Science: Microbiology
Website: https://journals.asm.org/journal/spectrum

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