Isolation and characterization of bacterial root endophytes with potential to enhance plant growth from Kenyan Basmati rice

Abstract

Rice is an important grain food crop being a staple food for a large part of the world's human population including Kenya. Rice production in Kenya is limited by various factors, the most significant being application of fertilizers, which are expensive, unaffordable and not eco-friendly. In this study, a survey of bacterial root endophytes was carried out. Seventy three bacterial rice root pure isolates from farms and research fields in Mwea and Ahero were characterized using morphological, biochemical and molecular techniques. Ten isolates were identified to produce indoleacetic acid (IAA) while sixty seven showed a positive outcome for phosphate solubilisation. All these isolates were confirmed to have the potential to fix nitrogen based on acetylene reduction assay (ARA). Phylogenetic analysis of the twenty eight selected isolates clustered into four different genera namely Pseudomonas, Bacillus, Enterobacter and Micrococcus which was in agreement with other previous tests. Isolates M31 and M32 from Mwea Basmati 370 rice were shown to promote plant growth which makes them potential candidates for the development of a biofertilizer. Therefore, if used they would consequently enhance affordable production of Kenyan basmati rice. This will not only eradicate poverty and increase food security, but also help conserve microbial diversity.