CHARACTERIZATION OF PAENIBACILLUS DURUS (PNF16) A NEW ISOLATE AND ITS SYNERGISTIC INTERACTION WITH OTHER ISOLATED RHIZOBACTERIA IN PROMOTING GROWTH AND YIELD OF CHICKPEA

Abstract

Application of PGPR in crop production and protection is well known and can also contribute in reducing use of agrochemicals. However, the performance of PGPR is influenced by various biotic and abiotic factors. Isolating new efficient PGPR strain well adapted to local soil agroclimatic conditions is expected to perform with more consistency. In this study five selected rhizobacteria isolated previously were first tested in vitro for plant growth promoting (PGP) characteristics. One of the isolate PNF16 was identified as Paenibacillus durus by 16S rRNA gene sequence analysis. PNF16 alone and in combination with other rhizobacteria (Azotobacter (AZT3), Achromobacter (PNF11), Bacillus (Bc1), Pseudomonas (Ps5) and Mesorhizobium (IARI) were tested for plant growth promoting effect under pot conditions in two consecutive years. PNF16 was found to produce 21.7 µg ml-1 of indole acetic acid like substances, hydroxymate type of siderophores (Salicylate type 11 µg ml-1 and benzoate type 6.5 µg ml-1) and solubilized phosphate (405.33 µg ml-1). PNF16 -Mesorhizobium combination was found significantly better compared to other combinations for growth parameters, nodulation and yield of chickpea over control. Similar study was also performed for other tested strain. Significant increase in plant growth (32%), nodulation (43%) compared to untreated control was recorded. Co-inoculation also showed synergy and increased the number of pods per plant, 1000-grain weight, dry matter yield, grain yield and protein content by 23%, 22%, 21%, 18% and 4.4% respectively, compared to control. The results indicated the potential usefulness of PNF16 alone and in combinations in enhancement of nodulation and stimulation of plant growth in chickpea and adapted to soil condition of the region.