Novel potassium solubilizing bacterium Pseudomonas marginalis (EU-MRN-08) and its role in plant growth promotion of maize (Zea mays L.)
摘要
Agricultural productivity is increasingly being hampered by potassium (K) deficiency. It is a vital mineral that plays a significant part in the biochemical and physiological processes of many plants. Balanced nutrient administration always tends to ensure greater plant growth and development. The soils have lost K more quickly due to negligent usage of inorganic K fertilizer. To retain soil sustainability and facilitate plant uptake of K nutrients, an alternative and novel approach is required. The aim of present study was to isolate efficient potassium solubilizing bacteria (KSB) from rhizosphere of maize grown in Kinnaur District. Molecular identity and authenticity were accomplished using the 16S rRNA gene sequencing and phylogenetic approach. Therefore, in the present study, efficacy of KSB for mediating maize plant growth and productivity were assessed in order to enhance crop response to bacterial inoculation by expanding our understanding of microbial ecology. A total of 46 KSB morphotypes were sorted out and quantifying in Alexsandrow broth and strains showed K solubilizing attributes ranging from 21.1 ± 0.02 mg L−1 to 222.1 ± 0.02 mg L−1 in mica and 19.3 ± 0.02 mg L−1 to 196.3 ± 0.02 mg L−1 in alumino silicate. On the basic of K solubilizing attribute, EU-MRN-08 showed maximum K solubilizing attribute upto 222.1 ± 0.02 mg L−1 in mica and 196.3 ± 0.02 mg L−1 in alumino silicate and identified as EU-MRN-08 Pseudomonas marginalis (PQ818272). Results from a subsequent green house and field experiment indicated that application of KSB distinctly increased maize growth and physiological parameters. To the best of our knowledge, the present investigation is first report on EU-MRN-08 Pseudomonas marginalis as K-solubilizer associated with rhizospheric region of maize and also reported first time as niche specific bacterium from Sapni village of Kinnaur District. The finding concluded that, application of Pseudomonas marginalis EU-MRN-08 was found to be greater ability to enhance the growth of maize and ideal bioinoculant for sustainable agriculture.