AUTHOR=Ye Chuwen , You Yanbo , Li Wenjie , Jing Tingting , Mo Minghe , Qiao Min , Yu Zefen 

TITLE=Diversity of Trichoderma species associated with the black rot disease of Gastrodia elata, including four new species

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1420156

DOI=10.3389/fmicb.2024.1420156

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p><italic>Trichoderma</italic> species establish symbiotic relationships with plants through both parasitic and mutualistic mechanisms. While some <italic>Trichoderma</italic> species act as plant pathogenic fungi, others utilize various strategies to protect and enhance plant growth.</p></sec><sec><title>Methods</title><p>Phylogenetic positions of new species of <italic>Trichoderma</italic> were determined through multi-gene analysis relying on the internal transcribed spacer (ITS) regions of the ribosomal DNA, the translation elongation factor 1-α (<italic>tef1-</italic>α) gene, and the RNA polymerase II (<italic>rpb2</italic>) gene. Additionally, pathogenicity experiments were conducted, and the aggressiveness of each isolate was evaluated based on the area of the cross-section of the infected site.</p></sec><sec><title>Results</title><p>In this study, 13 <italic>Trichoderma</italic> species, including 9 known species and 4 new species, namely, <italic>T. delicatum, T. robustum, T. perfasciculatum</italic>, and <italic>T. subulatum</italic> were isolated from the diseased tubers of <italic>Gastrodia elata</italic> in Yunnan, China. Among the known species, <italic>T. hamatum</italic> had the highest frequency. <italic>T. delicatum</italic> belonged to the Koningii clade. <italic>T. robustum</italic> and <italic>T. perfasciculatum</italic> were assigned to the Virens clade. <italic>T. subulatum</italic> emerged as a new member of the Spirale clade. Pathogenicity experiments were conducted on the new species <italic>T. robustum, T. delicatum</italic>, and <italic>T. perfasciculatum</italic>, as well as the known species <italic>T. hamatum, T. atroviride</italic>, and <italic>T. harzianum</italic>. The infective abilities of different <italic>Trichoderma</italic> species on <italic>G. elata</italic> varied, indicating that <italic>Trichoderma</italic> was a pathogenic fungus causing black rot disease in <italic>G. elata</italic>.</p></sec><sec><title>Discussion</title><p>This study provided the morphological characteristics of new species and discussed the morphological differences with phylogenetically proximate species, laying the foundation for research aimed at preventing and managing diseases that affect <italic>G. elata</italic>.</p></sec>