Identification and characterization of root nodule associated bacteria from chickpea germplasm lines

Present study explored the genetic variability of chickpea minicore lines to understand the diversity of endophytic bacteria. A total of 395 nodule associated bacteria from healthy root nodules of chickpea and 30 bacterial isolates were identified based on 16SrDNA sequence similarity and characterized for plant growth promoting traits. BLAST analysis indicated that 16.67% of tested isolates showed only 68–96% sequence similarity with available dataset at NCBI. In total, 22 bacterial isolates belong to Gram negative Genus via. Enterobacter, Rhizobium, Stenotrophomonas, Pseudomonas, and Burkholderia while 8 are Gram positive (Bacillus, and Brevibacillus). Bacterial isolate No. 329B recorded very low 16S rDNA sequence similarity (69%) to Pseudomonas required further analysis for identifying its appropriate taxonomy. He was detected in isolate 281 while nodAB was detected in isolate 365 and 369 of Burkholderia. All 30 bacterial isolates gave negative results for mineral phosphate solubilization as well as HCN production, while 9 isolates produced siderophore. Two bacterial isolates (251A, 265A) were identified for IAA production. Further research on revealing endophytic bacterial diversity and their plant beneficial traits may lead to development and commercialization of microbial formulations to enhance chickpea yield under rainfed condition.