AUTHOR=Wang Huimin , Liu Caixia , Yue Fangzheng , Yan Dong-Hui , Lu Quan 

TITLE=Identification of ophiostomatalean fungi associated with Tomicus pilifer infesting Pinus koraiensis in Northeastern China

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.919302

DOI=10.3389/fmicb.2022.919302

ISSN=1664-302X

ABSTRACT=<p>Ophiostomatalean fungi usually facilitate bark beetles to infest tree hosts and seriously endanger the health of coniferous forests. <italic>Tomicus pilifer</italic> Spessivtsev is a common endemic bark beetle in Asia and primarily threatens <italic>Pinus koraiensis</italic>. <italic>Tomicus</italic> species have similar morphology; however, they can be differentiated by their genetic characteristics through phylogenetic analyses. To date, the 28S rDNA sequence of <italic>T. pilifer</italic> and the diversity of ophiostomatalean fungi associated with <italic>T. pilifer</italic> have not been reported. In this study, we aimed to clarify the taxonomic status of <italic>T. pilifer</italic> and identify ophiostomatalean fungi associated with <italic>T. pilifer</italic> infesting <italic>P. koraiensis</italic> in northeastern China. In total, 315 ophiostomatalean fungal strains were isolated from 62 adults of <italic>T. pilifer</italic> and 220 tissue samples from <italic>T. pilifer</italic> galleries in Jilin Province. Thirty-five representative strains were further identified by comparing their morphological and physiological characteristics and conducting the phylogenetic analysis of ITS, ITS2-LSU, TUB2, and TEF1-α. We identified nine species of ophiostomatalean fungi belonging to four genera, which included six novel species (<italic>Ceratocystiopsis changbaiensis</italic> sp. nov., <italic>Leptographium linjiangense</italic> sp. nov., <italic>Leptographium qieshaoense</italic> sp. nov., <italic>Ophiostoma piliferi</italic> sp. nov., <italic>Ophiostoma tonghuaense</italic> sp. nov., and <italic>Ophiostoma yaluense</italic> sp. nov.), two previously described species (<italic>Graphilbum interstitiale</italic> and <italic>Ophiostoma fuscum</italic>), and one undefined specie (<italic>Ceratocystiopsis</italic> sp. 1). To the best of our knowledge, this is the first report of <italic>G</italic>. <italic>interstitiale</italic> and <italic>O</italic>. <italic>fuscum</italic> in China and the fungal diversity of ophiostomatalean in <italic>T. pilifer</italic>. The dominant species were <italic>O. piliferi</italic> and <italic>L. qieshaoense</italic>, representing 39.37% and 35.87% of the isolates, respectively. The results of this study provide valuable information on the symbiotic relationship between bark beetles and ophiostomatalean fungi.</p>