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Diversity of Orchid Mycorrhizal Fungi in selected terrestrial orchids from Western Ghats, Karnataka, India

Author Affiliations

  • 1Department of Botany, Government Science College, N.T. Road, Bangalore-01, Karnataka, India

Res. J. Recent Sci., Volume 15, Issue (3), Pages 96-100, July,2 (2026)

Abstract

Orchids form mutualistic associations with a specialized group of fungi known as orchid mycorrhiza, particularly during early stages of development. This study investigates mycorrhizal associations in selected terrestrial orchid species. Transmission electron microscopy was used to examine fungal structures, measure hyphal and peloton dimensions, and assess the pattern of colonization within root tissues. Phylogenetic analysis was conducted to identify the associated fungal species. Fungal colonization was observed in 88% of the root cortex, indicating a strong symbiotic relationship. Entry of the fungus occurred mainly through root hairs, followed by the formation of tightly coiled hyphal structures, known as pelotons, within cortical cells. The spread of the fungus involved cell-to-cell penetration, and both intact and degraded pelotons were observed within the cortex. Fungal genera such as Tulasnella and Rhizoctonia were identified from root samples. Seed germination experiments using the isolated fungi demonstrated their role in promoting germination. These findings contribute to understanding the processes of colonization, isolation, and characterization of orchid mycorrhizal fungi, as well as the establishment of symbiotic relationships. Such knowledge may support conservation efforts and help address ecological challenges associated with orchid species.

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