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Accueil du site → Master → Inde → 2020 → Isolation and Characterization of Drought Tolerant Plant Growth Promoting Rhizobacteria PGPR Strains Associated with Spilanthes acmella Murr from Western Himalayas

Shoolini University of Biotechnology and Management Sciences (2020)

Isolation and Characterization of Drought Tolerant Plant Growth Promoting Rhizobacteria PGPR Strains Associated with Spilanthes acmella Murr from Western Himalayas

Devi, Menaka

Titre : Isolation and Characterization of Drought Tolerant Plant Growth Promoting Rhizobacteria PGPR Strains Associated with Spilanthes acmella Murr from Western Himalayas

Auteur : Devi, Menaka

Université de soutenance : Shoolini University of Biotechnology and Management Sciences

Grade : Doctor of Philosophy (PhD) 2020

Résumé
Various abiotic stresses reduce crop production, degrade the food quality and constraint food security globally. Due to drought stress plant gets affected at physiological, biochemical and molecular level. As we know that the soil fertility gets degraded and environment get polluted by the excess and continuous use of inorganic fertilizers and pesticides in agriculture. Therefore, it is necessity of the present scenario to develop sustainable and non-toxic means to ensure good crop production. The use of plant growth promoting rhizobacteria (PGPR) offers an economically fascinating and ecologically sound ways for protecting plants against stress condition. PGPR not only exhibit biocontrol and biofertilizer traits but also help plant to survive in adverse environmental conditions. In this study the rhizobacteria are being explored for their ability to tolerate drought stress and their potential to act as plant growth promoter. Herein, we have isolated bacterial strains from the rhizosphere of Spilanthes acmella Murr. (toothache plant) found in Shivalik hills region of Himachal Pradesh. We screened nine drought tolerant culturable bacteria by analysing their ability to survive in varying concentration of polyethylene glycol (PEG) (10%-50%) which is further supported by their 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity and their ability to release exopolysaccharides (EPS). The 16S rDNA analysis revealed that the isolated strains belong to four genera i.e., Klebsiella, Enterobacter, Burkholderia and Pantoea. These isolates also harbored plant growth promoting potential such as solubilization of phosphate and, production of indole-3-acetic acid (IAA), siderophore, ammonia, hydrogen cynide (HCN) and antifungal activity. The Enterobacter cloacae showed maximum drought tolerance among all the other isolated strains it is able to grow in with 50% PEG. This study revealed that drought stress of 60% PEG inhibited the growth of seedlings but the bacterization with the isolated strains stimulated seedling growth for Triticum aestivum. Hence, we conclude that these drought tolerant PGPR from rhizosphere of S. acmella Murr. can be used to improve survival and growth of plant under drought stress.

Présentation et version intégrale (Shodhganga)

Page publiée le 19 mars 2021