An amalgam of pathogenic and beneficial endophytic fungi colonizing four Dendrobium species from Meghalaya, India

Abstract

Endophytic fungi are known to play an important role in driving the evolution of plants by conferring adaptational advantages to their host through the production of secondary metabolites and phytohormones. In this study, we evaluated the diversity and phylogenetic relationship of endophytic fungal communities from four Dendrobium species viz., Dendrobium chrysanthum, Dendrobium heterocarpum, Dendrobium hookerianum, and Dendrobium longicornu of Meghalaya, India. A total of 51 culturable endophytic fungi were isolated from the four selected orchid species. The isolates were identified based on nuclear large subunit sequences into 33 species. Approximately 91% of the isolates showed affinity to Ascomycetes, while 9% of the isolates showed BLAST search similarity to Basidiomycetes. The most common genera were Trichoderma and Xylaria. The most prevalent genera were Fusarium, which was detected in all the four Dendrobium species followed by Diaporthe, which was present in three Dendrobium species viz., D. chrysanthum, D. hookerianum, and D. heterocarpum. The Shannon index value of endophytic fungal communities was the highest in D. chrysanthum (2.66), while D. longicornu (1) had the highest Evenness index. The present study revealed that endophytic fungi in these orchids are an amalgam of pathogenic and beneficial fungi, which have, at the least, switched their lifestyle to asymptomatic endophyte in their host. To our knowledge, this is the first such report on the diversity of endophytic fungi in the four selected Dendrobium species from Meghalaya, India.

How Mycorrhizal Associations Influence Orchid Distribution and Population Dynamics

“…Moreover, they also play a role in mobilizing soil nutrients in the rhizosphere to improve orchid viability and environmental adaptability, and serve as new sources of phytochemicals and bioactive substances to protect the host from soil pathogens. Hence, these ONF provide the plants with promising medicinal and agricultural breeding prospects (Chen et al, 2006;Yuan et al, 2009;Aly et al, 2010;Novotná et al, 2018;Sisti et al, 2019;Hajong and Kapoor, 2020;Wu et al, 2020). Furthermore, ONF may interact with OMF to influence the distribution and population dynamics of orchids.…”