MORPHOLOGICAL AND BIOCHEMICAL CHARACTERISATION OF BACTERIAL ROOT ENDOPHYTIC ISOLATES WITH POTENTIAL TO ENHANCE PLANT GROWTH FROM KENYAN (MWEA) BASMATI RICE

Abstract

Rice is an important grain food crop being a staple food for a large part of the world's human population. Anendophyte is an endosymbiont, often a bacterium or fungus, that lives within a plant for at least part of its lifewithout causing apparent disease. In this study, bioprospecting for bacterial rice root endophytes was explored. 66bacterial pure isolates were isolated from the 138 root samples collected from farmers’ and research fields. Theywere morphologically characterized and screened for biological activities. All isolates were gram negative rods.Two phosphates were used for phosphate solubilisation, in which case more positive response was observed incalcium phosphate than in Alluminium phosphate. Nine isolates were identified to produce IAA- indoleacetic acidimplying potential to enhance plant growth. All isolates tested negative for denitrification test. The biochemicaltests carried out helped reduce the number of isolates from 66 to 30 upon similarity and uniqueness. All 30selected isolates were confirmed to have potential to fix nitrogen based on acetylene reduction assay (ARA). Theselected 30 isolates have demonstrated to have the potential to promote plant growth in at least one biologicalmechanism. This is the first study on the endophytic nature of Kenyan (Mwea) Basmati rice endophytes. Thesemicroorganisms may be useful for agriculture (biofertilizer) to enhance affordable production for Kenyan basmatirice farmers, and also used in other applications. This will contribute to increased yield and trade of Kenyanbasmati rice to eradicate poverty and increase food security, and help conserve microbial diversity.