Nodule inhabiting non-rhizobial bacteria and their influence on growth of selected leguminous plants of Bangladesh

The present study aimed to identify non-rhizobial bacteria present in the root nodules of four legume plants viz. Arachis hypogaea L., Dolichos lablab L., Vigna mungo L., and Sesbania sesban L. grown in Bangladesh. Pure isolates of the bacteria obtained from the surface sterilized root nodules were identified by sequencing of 16S rRNA gene. A total of 13 isolates belonging to 10 genera under 7 families were obtained. Effects of these non-rhizobial bacteria on nodulation, plant height, shoot biomass, and leaf chlorophyll contents were compared in between A. hypogaeae L. and V. mungo L. Of all the isolates identified, Klebsiella sp. and Enterobacter sp. produced nodules in both V. mungo L. and A. hypogaea L. and Bacillus sp. produced nodules only in V. mungo L. Results also demonstrated that most of the isolates enhanced shoot height, shoot biomass and leaf chlorophyll contents in V. mungo L. but not in A. hypogaea L. Results of the present study are thus relevant for enhancing our knowledge about the beneficial use of non-rhizobial bacterial in growth and development of leguminous crops in order to secure sustainable agriculture.