<i>Trichoderma</i> species from typical forests system in China: Geographical distribution and comparative genome-wide evaluation of selected species related to biocontrol

In this study, we isolated 633 <i>Trichoderma</i> strains from 15 forest types across six climate zones. Our findings revealed that species diversity was highly underestimated, with 239 isolates identified as new species based on ITS, <i>rpb2</i>, and <i>tef1</i> sequences. In tropical and subtropical regions, the mean values for the haplotype Chao1 richness index and the Shannon-Weiner diversity index are 73 and 3, respectively, significantly higher than those in temperate regions. <i>Trichoderma</i> cf. <i>taiwanense</i> was the most widely distributed, followed by <i>T. asperellum</i>, rather than widely reported <i>T. harzianum</i>. The maximum entropy model was used to analyse the effects of climatic factors on distribution of <i>T</i>. cf. <i>taiwanense</i> and <i>T. asperellum</i>, and showed that precipitation in the warmest quarter was the most important factor influencing their distribution. <i>T</i>. cf. <i>taiwanense</i> zj625y demonstrated significantly higher antagonistic ability, outperforming the other tested <i>Trichoderma</i> species. The genomic characteristics of <i>T</i>. cf. <i>taiwanense</i> were firstly revealed with 36.49 Mbp in size and contained 17 genes of β-1,3-glucanase and 24 genes of chitinase genes. Additionally, the activities of endochitinase, endo-1,3(4)-β-glucanase, and metallopeptidase were highly expressed in culture. Metabolomic analysis further identified specific substances produced by <i>T</i>. cf. <i>taiwanense</i> zj625y, such as ergothioneine, (3-carboxypropyl) trimethylammonium cation, NG-dimethyl-L-arginine (ADMA), N-acetyl-D-glucosamine, stearic acid, tyramine, citrate, L-leucine, and acetylcarnitine, which contribute to its potential antagonism and environmental adaptability.