Application of Plant Growth Promoting Rhizobacteria in Growth Enhancement of a Multipurpose crop Crotalaria Juncea (Sunhemp) in Saline Soil

Abstract

Salinity is a major abiotic stress which limits the crop productivity.
In this study salt tolerant bacteria were isolated from root nodules
of Crotalaria juncea plant collected from different salt affected sites.
Salt tolerance activity of all the isolates was checked and it was
observed that 47% of the isolates showed up to 8% salt tolerance.
On the basis of morphological, biochemical and physiological characterization
isolates were found to be Gram negative, rod shaped
and motile bacteria that belong to rhizobia. All the isolates also
showed nodulation in host plant. Most of the isolates were positive
for various plant growth promoting attributes. On the basis of salt
tolerance and plant growth promoting characterization isolate CR6
was selected for further studies. CR6 showed positive results for
phosphate and zinc solubilisation, and was able to produce indole
acetic acid (IAA), siderophore and exopolysaccharides (EPS). CR6
also showed nitrogen fixation and ACC deaminase activity. CR6 was
applied on Crotalaria plant to enhance growth in saline soil. After
application of CR6 seed germination rate and various growth parameters
such as root length, shoot length, nodule number, fresh weight,
dry weight, leaves count, chlorophyll and proline content of plants
were enhanced in comparison to control, hence CR6 can be used as
an efficient bioinoculant to enhance crop growth in saline soil.