Exploration, Isolation and Characterization of Indigenous Rhizobacteria from Trigonella foenum Graecum L. (Fenugreek) rhizosphere as PGPR Candidates in producing IAA and Gibberellic

Abstract

Indian Spices are the primary commodities that are important to enhance agricultural economy of any country because of its higher impact value and export capabilities. India is the leading country for supplements of spices in the worldwide market. According to International Organization of Standardization, India is the largest consumer and exporter of spices (in year 2020-21, India exported 1,758,964.79 tons of spices) (Jabborova et. al., 2022). India exports approximately of 75 spices out of 109 varieties listed including pepper, chili, turmeric, ginger, cardamom, coriander, cumin, fennel, fenugreek, celery, nutmeg, mace garlic, tamarind and vanilla etc. Gujarat contributes substantially in growing spices such as Fenugreek, Dill seed, Fennel, Cumin, Coriander, Chilli and Garlic (Yamuna et.al, 2022). Trigonella foenum Graecum L. (Fenugreek) is herb and one of the Indian spices which is employed for medicinal purposes, food industry and in cosmetic industry. According to Spices Board India Ministry of commerce & Industry, the Government of India, Trigonella foenum Graecum L. (Fenugreek) production in 2016-17 by Gujarat was estimated about 28,920 tons, which decreased to 14,173 in 2019-20 and in 2020-21 year, it was about 13,579 tons. The production of Fenugreek is drastically reducing in Gujarat. In order to increase the production in agriculture excessive use of chemical fertilizers is employed which leads to soil deterioration, reduces in soil fertility and generate wide gap between nutrients removed from soil and nutrient supplied (Yamuna et.al, 2022) To reduce the extensive use of chemical fertilizers, a sustainable method is to used which is based on soil beneficial microorganism. These microorganisms help to maintain nutrients level of soil and plant, and also helps to improve soil fertility and enhance plant growth and development. Plant Growth Promoting Rhizobacteria (PGPR) are the soil beneficial microorganisms which helps in improving soil health and growth enhancement for the plant. The phytohormones production such as Indole Acetic Acid (IAA) and Gibberellic acid by these PGPR plays a crucial role in enhancement of the plant growth (Khan et. al., 2020). These phytohormones also help to tolerate biotic and abiotic stresses. Indole Acetic Acid helps in improving seed germination, increase in plant height and seedling development, and Gibberellic acid helps in seed germination, responds to abiotic stresses and increases stem elongation and better flowering (Plant et.al, 2020) In the present study we will isolate and characterize potent rhizobacteria and screen for their ability to produce phytohormones from the soil samples of Trigonella foenum Graecum L. (Fenugreek) from the different regions of Gujarat.