AUTHOR=Cao Zi-Jian , Zhao Juan , Liu Yu , Wang Shou-Xian , Zheng Su-Yue , Qin Wen-Tao 

TITLE=Diversity of Trichoderma species associated with green mold contaminating substrates of Lentinula edodes and their interaction

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 14 - 2023

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1288585

DOI=10.3389/fmicb.2023.1288585

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>The contamination of <italic>Trichoderma</italic> species causing green mold in substrates poses a significant obstacle to the global production of <italic>Lentinula edodes</italic>, adversely impacting both yield and quality of fruiting bodies. However, the diversity of <italic>Trichoderma</italic> species in the contaminated substrates of <italic>L. edodes</italic> (CSL) in China is not clear. The purpose of this study was to assess the biodiversity of <italic>Trichoderma</italic> species in CSL, and their interactions with <italic>L. edodes</italic>.</p></sec><sec><title>Methods</title><p>A comprehensive two-year investigation of the biodiversity of <italic>Trichoderma</italic> species in CSL was conducted with 150 samples collected from four provinces of China. <italic>Trichoderma</italic> strains were isolated and identified based on integrated studies of phenotypic and molecular data. Resistance of <italic>L. edodes</italic> to the dominant <italic>Trichoderma</italic> species was evaluated in dual culture <italic>in vitro</italic>.</p></sec><sec><title>Results</title><p>A total of 90 isolates were obtained and identified as 14 different <italic>Trichoderma</italic> species, including six new species named as <italic>Trichoderma caespitosus</italic>, <italic>T. macrochlamydospora</italic>, <italic>T. notatum</italic>, <italic>T. pingquanense</italic>, <italic>T. subvermifimicola</italic>, and <italic>T. tongzhouense</italic>, among which, <italic>T. atroviride</italic>, <italic>T. macrochlamydospora</italic> and <italic>T. subvermifimicola</italic> were identified as dominant species in the CSL. Meanwhile, three known species, namely, <italic>T. auriculariae</italic>, <italic>T. paraviridescens</italic> and <italic>T. subviride</italic> were isolated from CSL for the first time in the world, and <italic>T. paratroviride</italic> was firstly reported to be associated with <italic>L. edodes</italic> in China. Notebly, the in vitro evaluation of <italic>L. edodes</italic> resistance to dominant <italic>Trichoderma</italic> species showed strains of <italic>L. edodes</italic> generally possess poor resistance to <italic>Trichoderma</italic> contamination with <italic>L. edodes</italic> strain SX8 relatively higher resistant.</p></sec><sec><title>Discussion</title><p>This study systematically investigated the diversity of <italic>Trichoderma</italic> species in the contaminated substrate of <italic>L. edodes</italic>, and a total of 31 species so far have been reported, indicating that green mold contaminated substrates of edible fungi were undoubtedly a biodiversity hotspot of <italic>Trichoderma</italic> species. Results in this study will provide deeper insight into the genus <italic>Trichoderma</italic> and lay a strong foundation for scientific management of the <italic>Trichoderma</italic> contamination in <italic>L. edodes</italic> cultivation.</p></sec>