Author(s)

Ramesh Raj Puri¹, Sangharash Raj Dangi², Sabitri Adhikari Dhungana^1,2, Kazuhito Itoh^1,3*

¹The United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan.
²Nepal Agricultural Research Council, Kathmandu, Nepal.
³Faculty of Life and Environmental Science, Shimane University, Shimane, Japan.

There is no information on Nepalese sweet potato endophytes. We isolated 243 endophytic bacteria belonging to 34 genera in six classes from 12 locations of Nepal. Among them, the predominant classes were Bacilli and Gammaproteobacteria. The principal component analysis revealed that the composition of bacterial classes was unrelated to the environmental parameters of the sampling sites. Regarding their plant growth promoting potentials, 57% of the strains demonstrated indole-3-acetic acid (IAA) producing ability while 5% strains had nitrogen fixing gene (nifH) and acetylene reduction assay (ARA) activity. The representative strains in all six classes showed antagonistic effect against bacterial pathogens while only Bacillus strain showed the effect against fungal pathogen. For endophytic traits, cellulase activity was observed in 5 classes, while pectinase activity was only in Proteobacteria. Fresh weight and vine length of sweet potato increased by inoculating mixed cultures of the isolates from each location.

Sweet Potato, Endophytic Bacteria, IAA Production, Nitrogen Fixation, Antagonistic Effects

Puri, R. , Dangi, S. , Dhungana, S. and Itoh, K. (2018) Diversity and Plant Growth Promoting Ability of Culturable Endophytic Bacteria in Nepalese Sweet Potato. Advances in Microbiology, 8, 734-761. doi: 10.4236/aim.2018.89049.