Morphology and Phylogeny of <i>Pestalotiopsis</i> ( <i>Sporocadaceae</i> , <i>Amphisphaeriales</i> ) from <i>Fagaceae</i> Leaves in China

Abstract

<i>Fagaceae</i> is a family of flowering plants widely distributed in the Northern Hemisphere, including deciduous and evergreen trees and shrubs. Species of <i>Pestalotiopsis</i> are well-known agents of leaf spot diseases, but targeted sampling on <i>Fagaceae</i> is still missing. To determine the diversity of <i>Pestalotiopsis</i> species associated with <i>Fagaceae</i> leaf spot in China, investigations were conducted in the main areas of <i>Fagaceae</i> distribution from 2016 to 2021. Diseased leaf tissues were collected, and fungal isolates were obtained from leaf spots. In the present study, 43 isolates of <i>Pestalotiopsis</i> were studied based on combined morphology and phylogeny. As a result, 10 new species were identified, <i>viz.</i>, <i>Pestalotiopsis anhuiensis</i>, <i>P. castanopsidis</i>, <i>P. changjiangensis</i>, <i>P. cyclobalanopsidis</i>, <i>P. foliicola</i>, <i>P. guangxiensis</i>, <i>P. guizhouensis</i>, <i>P. lithocarpi</i>, <i>P. shaanxiensis</i>, and <i>P. silvicola</i>, and six new host records were recognized. <b>IMPORTANCE</b> <i>Pestalotiopsis</i> is a common fungal genus inhabiting plant tissues as endophytes, pathogens, and saprophytes. <i>Fagaceae</i> is a plant family including many important tree species, such as <i>Castanea mollissima</i> and <i>Quercus</i> spp. In this study, diseased leaves of <i>Fagaceae</i> in China were investigated, and 16 <i>Pestalotiopsis</i> species were identified based on morphology and phylogeny of combined loci of internal transcribed spacers (ITS), the translation elongation factor 1-α (<i>tef1</i>), and the beta-tubulin (<i>tub2</i>) genes. Among these, 10 new species were found, and six new host records were revealed. Our study significantly updates the taxonomy of <i>Pestalotiopsis</i> and enhances our understanding of leaf diseases of <i>Fagaceae</i> hosts.