Diversity and biological properties of saprobic asscomycota on Chromolaena odorata and Bidens pilosa

Abstract

Bidens pilosa and Chromolaena odorata are widespread weeds in the Asteraceae, recognized as invasive species in many regions worldwide. Comparative research on fungal diversity across Asteraceae weeds remains limited, with only a few studies conducted on the diversity of saprobic fungi on these weeds. Further research is necessary to discover the potential ecological or biotechnological benefits of these fungi. In this study, saprobic fungi collected from Bidens pilosa and Chromolaena odorata in northern Thailand comprise 54 species, distributed across 33 genera, 21 families, and seven orders within Dothideomycetes and Sordariomycetes. Among them, 23 species are identified as novel species (Albifimbria bidentis, Austropleospora chromolaenae, Bahusandhika bidentis, Bartalinia bidenticola, Dothiorella asteracearum, D. chromolaenae, Diaporthe asteracearum, D. chromolaenicola, Forliomyces bidentis, Fusarium bidentis, F. chromolaenae, Kalmusia thailandica, Memnoniella asteracearum, Murichromolaenicola thailandica, Neoroussoella chromolaenae, Pseudothyridariella asteracearum, Ps. thailandica, Pseudolophiostoma chromolaenae, Pseudoneoconiothyrium chromolaenae, Pseudo. thailandicum, Pseudoroussoella bidenticola, Sarocladium bidentis, and Tremateia asteracearum). In addition, 25 new host records (Aplosporella artocarpi, Acrocalymma pterocarpi, Bahusandhika indica, Chromolaenicola chiangraiensis, C. siamensis, C. thailandica, Colletotrichum gigasporum, C. truncatum, Diaporthe biconispora, Dictyocheirospora nabanheensis, Dendryphion hydei, Fusarium hainanense, Lasiodiplodia henanica, L. theobromae, Leptospora thailandica, Memnoniella levispora, Montagnula chromolaenae, Neodendryphiella mali, Neoroussoella entadae, Periconia byssoides, Pseudoithomyces chartarum, Remotididymella anthropophila, R. fici-microcarpae, Torula canangae, and T. mackenziei) and six reference specimens (Aplosporella hesperidica, Chromolaenicola nanensis, Rhytidhysteron bruguierae, Lophiostoma longiappendiculatum, Montagnula donacina, and Torula fici) were documented. The species boundaries were delineated based on morphology and multi-gene phylogenetic approaches. Furthermore, the preliminary assays revealed antibacterial activity in 31 species against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus, highlighting their biotechnological potential. Fungal metabolites of ethyl acetate extract of M. asteracearum were investigated using LC-QTOF analysis. The results revealed a total of 142 compounds categorized into alkaloids, carbohydrates and derivatives, heterocyclic compounds, organic acids and carboxylic acids, lipids and fatty acids, terpenoids and steroids. The detailed morphologies, illustrations and characterized compounds of M. asteracearum were provided together with its chemical profiles. A worldwide checklist documented 76 fungal taxa on Bidens pilosa and 145 fungal taxa on Chromolaena odorata, underscoring their roles as reservoirs of fungal diversity. This study expands the taxonomic and ecological understanding of microfungi associated with invasive Asteraceae weeds in Thailand and the host-fungal relationships in a global context by encouraging future mycological and ecological research efforts.