Application of Plant Growth Promoting Rhizobacteria (PGPR) Isolated from the Rhizosphere of Sesbania bispinosa on the Growth of Chickpea (Cicer arietinum L.)

Abstract

Plant Growth Promoting Rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by wide variety of mechanism. Initially twelve isolates of bacteria designated as DD1to DD12, isolated from the rhizospheric soil of Dhaincha (Sesbania bispinosa) were screened on the basis of their efficiency in PGPR characteristics and finally three most efficient PGPR strains, i.e. - DD3, DD4 and DD6, were selected and further identified as Escherichia coli DACG2 (GenBank Accession number JN858966) Pseudomonas fluorescens strain DACG3 (GenBank Accession No. KP641168) Burkholderia sp. DACG1 (GenBank Accession No. JN639877) using 16 S rRNA sequencing technology. Subsequently, to investigate the effect of PGPR isolates on the growth of Cicer arietinum L., a pot culture experiment and a field experiment were conducted using a randomized complete block design with 3 replications and 9 treatments. The treatments consisted of uninoculated control and all cases of single, dual and triple inoculants of these 3 bacteria. The maximum rates of plant height, number of leaves/plant, pod bearing branches, pods/plant, nodules/plant and 100 seed weight were recorded by applying the combined inoculation of Escherichia coli DACG2+ Pseudomonas fluorescens DACG3+ Burkholderia sp DACG1 as compared with other inoculation treatments and uninoculated control. Therefore, present study suggests that PGPR isolates viz. Escherichia coli, Pseudomonas fluorescens, and Burkholderia sp. may be used as biofertilizers to enhance the growth and productivity of chickpea.