Evaluation of PGPR Activity of Cow Dung Rhizobacterial Isolates and Their Effect on Wheat Plant Growth
DOI:
https://doi.org/10.53555/cfpyke85Keywords:
Cow dung, Klebsiella pneumoniae, Plant growth-promoting rhizobacteria, Wheat growth promoterAbstract
Plant growth-promoting rhizobacteria (PGPR) are beneficial microbes residing in the rhizosphere that enhance plant growth by supplying essential nutrients and protecting against pathogenic organisms. This study aimed to identify and characterize PGPR strains native to cow dung in India and assess their plant growth-promoting potential.Ten bacterial isolates (designated KG1 to KG10) were isolated and subjected to in vitro screening for PGPR traits. Among these, isolate KG9 demonstrated superior performance. Phylogenetic analysis of 16S rRNA sequences revealed that these isolates represent novel strains of Klebsiella pneumoniae.Isolate KG9 exhibited high production levels of key growth-promoting compounds: indole-3-acetic acid (786 µg/mL), gibberellic acid (9.52 mg/mL), and ammonia (0.85 mg/L). The strain was applied to wheat seeds using various methods, including seed priming, bacterial broth application before and after germination, and encapsulation in beads both pre- and post-germination. These treatments were compared to untreated control seeds. The most significant enhancement in shoot length (1.48-fold increase) was observed with bacterial broth application prior to germination (KG9B), while the greatest improvement in root length (1.40-fold increase) occurred with bead encapsulation before and after germination (KG9D*). Additionally, treated plants showed increased chlorophyll and proline content. K. pneumoniae KG9 exhibits multiple beneficial traits that support wheat growth and development. This strain holds promise for use as a safe and effective bio inoculant in sustainable agriculture.
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