HB Roghan¹, I Sekar²*, M Tilak³ and K Sivakumar⁴

¹PG Research Scholar, Department of Agroforestry, Forest College and Research Institute, Tamil Nadu Agricultural University, Mettupalayam-641 301, India
²Professor (Forestry), Department of Agroforestry, Forest College and Research Institute, Tamil Nadu Agricultural University, Mettupalayam-641 301, India
³Research Scholar, Department of Agroforestry, Forest College and Research Institute, Tamil Nadu Agricultural University, Mettupalayam-641 301, India
⁴Associate Professor (Soil Science), Department of Soil Science and Agricultural Chemistry, Tamil Nadu Agricultural University, Coimbatore-641 003, India

*Corresponding Author: I Sekar, Professor (Forestry), Department of Agroforestry, Forest College and Research Institute, Tamil Nadu Agricultural University, Mettupalayam-641 301, India.

Received: December 02, 2024; Published: January 15, 2025

Abstract

Frankia is a Gram-positive, nitrogen-fixing actinobacterium that forms a symbiotic association with actinorhizal plants, contributing to nitrogen fixation in the soil. It is also found free-living in soil environments. This study investigates the isolation of Frankia strains from the root nodules of Casuarina junghuhniana, a species that thrives in sodic soils and is known for its ability to withstand environmental stresses such as drought, salinity, and heavy metal contamination. Root nodules were surface-sterilized, processed, and incubated in Liquid Qmod media, which proved to be the most effective medium for Frankia growth. The study focused on the morphological characteristics of Frankia in culture, such as hyphal outgrowth, sporangia formation, and vesicle production, which are essential for nitrogen fixation. Hyphal outgrowth from vesicle clusters was observed within 3–10 days of inoculation, and the colonies were macroscopically visible within 14–20 days. The formation of sporangia occurred after 7–30 days, depending on the medium composition. Vesicles formed in nitrogen-deficient media were critical sites of nitrogen fixation, promoting plant growth. The results affirm that Frankia plays a key role in enhancing the growth and stress tolerance of Casuarina species, and highlight the effectiveness of Qmod medium for isolating Frankia from nodules. This study contributes to the understanding of Frankia-plant symbiosis and its potential for improving plant productivity in challenging environments.

Keywords:Casuarina junghuhniana; QMOD Media; Frankia; Isolation; Root Nodules

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Citation

Citation: I Sekar., et al. “Isolation of Frankia from Root Nodules of Casuarina junghuhniana Using the Liquid Qmod Media". Acta Scientific Microbiology 8.2 (2025): 35-38.

Copyright

Copyright: © 2025 I Sekar., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.