Additions to Memnoniella Species (Stachybotryaceae) Associated with Bidens pilosa and Chromolaena odorata (Asteraceae) in Northern Thailand and Their Potential Antibacterial Properties

Abstract

Memnoniella species were isolated from Bidens pilosa and Chromolaena odorata in northern Thailand. Maximum likelihood and Bayesian inference analyses of the combined dataset of ITS, tef1-α, rpb2 and tub2 were conducted to confirm their taxonomic placement within Memnoniella. Updated phylogenetic analyses, together with detailed descriptions, and illustrations of the isolates are also presented. Based on the morphology and multi-gene phylogeny, Memnoniella chromolaenae, M. oblongispora, and M. longistipitata are synonymized under M. levispora. Additionally, we introduced M. asteracearum (MFLUCC 25-0166) as a new species and reported a new host record of M. levispora. This study also provides preliminarily evaluation of the antibacterial activity of Memnoniella species against three bacterial pathogens: Bacillus subtilis (TISTR 1248), Staphylococcus aureus (TISTR Y4b), and Escherichia coli (TISTR 527), revealing the strongest activity observed against B. subtilis (TISTR 1248). In addition, our study contributes to expand the understanding of weed-associated saprobic fungal diversity by documenting Memnoniella species on Bidens pilosa and Chromolaena odorata.