Abstract

Isolation and Characterization of Phosphate Solubilizing Bacteria from Rhizosphere of Coffee Plant and Evaluating Their Effects on Growth and Development of Coffee Seedlings

Author(s): Vijay Singh Kunwar, Sharmila Chimouriya, Janardan Lamichhane and Dhurva Prasad Gauchan

Soil samples from the rhizosphere of 6 months old coffee seedling were collected. Phosphate Solubilizing Bacteria (PSB) were selected based on the quantitative ability to solubilize phosphate by measuring the clear zone surrounding the colonies in Pikovskaya’s agar. In total, 26 PSB were isolated. Best 8 isolates (PSB 1, PSB 2, PSB 8, PSB 10, PSB 11, PSB 14, PSB 19, and PSB 20) were selected and phenotypic and biochemical characteristics were carried out. Best four isolates were selected for germination assay, seedling growth experiment and greenhouse experiment. The effect of inoculation of PSB on germination of coffee seeds in vitro was evaluated and the result showed that all isolates (PSB 1, PSB 10, PSB 11, and PSB 20) enhanced germination by 51.72% - 58.82% over uninoculated water control. In seedling growth experiment, isolate PSB 20 isolates significantly enhanced shoot length and shoot fresh weight. In the greenhouse experiment conducted over 5 months, isolates PSB 20 and PSB 1 significantly enhanced coffee seedling shoot length, fresh shoot biomass and fresh root biomass over uninoculated water control plants. PSB 1 and PSB 10 significantly increased chlorophyll content and protein content in the coffee leaves. So, this study suggests bio-inoculants are able to stimulate plant growth, and recommends further experiments at field conditions