Enhancing potassium assimilation in soil for Zingiber officinale plant by rhizosphere bacterial isolate and optimization studies by response surface modeling

Abstract

Rhizosphere bacteria have always proven their worth towards their associated plant in their defense mechanism and nutritional functions. This study was made to understand the impact of rhizosphere-associated bacterial isolate PGK01 in complimenting associated Zingiber officinale plants in their potassium nutritional requirements. The screening of the isolate suggested that it can solubilize potassium, which the plant shall use for its nutritional purposes. Molecular sequencing suggested that the strain belonged to Bacillus subtilis, whose sequence has been submitted to NCBI under the accession number OQ652138. In-situ analysis of the effect of bacteria on the growth parameters and yield of the plant indicated that in the presence of microbe, plants tend to grow more when compared to without the organism. The optimization studies conducted by response surface modeling suggested that only half of the potassium fertilizer is necessary when a plant is grown in the presence of isolate compared to the conventional method. The adequacy of the statistical model was verified by analyzing the Sequential Model Sum of Squares and Cook’s distance diagnostic, wherein the observation proved the significance of the mathematical model.

Keywords

• Bacillus subtilis
• Plant growth promoters
• Plant nutrients
• Response surface modeling
• Rhizospheric soil
• Zingiber officinale