TITLE:
Diversity and Plant Growth Promoting Ability of Culturable Endophytic Bacteria in Nepalese Sweet Potato
AUTHORS:
Ramesh Raj Puri, Sangharash Raj Dangi, Sabitri Adhikari Dhungana, Kazuhito Itoh
KEYWORDS:
Sweet Potato, Endophytic Bacteria, IAA Production, Nitrogen Fixation, Antagonistic Effects
JOURNAL NAME:
Advances in Microbiology,
Vol.8 No.9,
September
25,
2018
ABSTRACT: 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.