AUTHOR=Wang Yongjun , Zeng Linzhou , Wu Jiayi , Jiang Hong , Mei Li 

TITLE=Diversity and effects of competitive Trichoderma species in Ganoderma lucidum–cultivated soils

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1067822

DOI=10.3389/fmicb.2022.1067822

ISSN=1664-302X

ABSTRACT=<p><italic>Ganoderma lucidum</italic> (GL) is a well-known medicinal mushroom that has been extensively cultivated. Our previous study has shown that abundant <italic>Trichoderma</italic> colonies grow on the casing soil surface, posing cultivation obstacles for GL. However, an understanding of species-level characteristics of <italic>Trichoderma</italic> strains and their adverse effects on GL growth is limited. This study aimed to investigate the diversity and potential effects of <italic>Trichoderma</italic> from GL-cultivated soils. Over 700 <italic>Trichoderma</italic> isolates were collected from two trails in Longquan Country, southeast China. Eight <italic>Trichoderma</italic> species, including <italic>T. atrioviride</italic>, <italic>T. guizhouense</italic>, <italic>T. hamatum</italic>, <italic>T. harzianum</italic>, <italic>T. koningiopsis</italic>, <italic>T. pleuroticola</italic>, <italic>T.</italic> sp. <italic>irale</italic>, and <italic>T. virens</italic>, were identified based on the combination alignment of <italic>tef-1α</italic> and <italic>rpb2</italic> sequences. The number of <italic>Trichoderma</italic> colonies increased dramatically during GL cultivation, with an increase of 9.2-fold in the Lanju trail. <italic>T. virens</italic> accounted for the most colonies (33.33 and 32.50% in Lanju and Chengbei, respectively) at the end of GL cultivation. The <italic>Trichoderma</italic> species growth varied but was satisfactory under different temperature or pH conditions. Moreover, <italic>Trichoderma</italic> species showed different adverse effects on GL growth. The non-volatile metabolites from <italic>T. virens</italic> and volatile metabolites from <italic>T. atroviride</italic> displayed the strongest antagonistic activity. Furthermore, the volatile 6-pentyl-2H-pyran-2-one (6-PP) showed a significant inhibitory effect on GL growth with an 8.79 μl mL<sup>−1</sup> headspace of 50% effective concentration. The different <italic>Trichoderma</italic> spp. produced different amounts of 6-PP. The most efficient 6-PP producer was <italic>T. atroviride</italic>. To the best of our knowledge, this study is the first to demonstrate the abundance of competitive <italic>Trichoderma</italic> species associated with GL cultivation. Our results would contribute to.</p>