Alginate Beads Encapsulated Auxin-Producing PGPR as a Biofertilizer Promotes Triticum aestivum Growth

Plant growth-promoting rhizobacteria (PGPR) can be utilized to enhance plant growth and production. The use of efficient PGPR is one of the effective ways to improve (wheat) growth and nutrition. The exploration of native rhizobacterial strains as biofertilizers with suitable carriers in immobilized form is an alternative way to prevent soil ecosystem pollution. In order to evaluate the potential of biofertilizers and multiple plant growth-promoting attributes, numerous experiments were conducted on isolated strains. The impact of auxin-producing rhizobacterial strains (APRS) on various growth parameters of wheat was examined through laboratory and field experiments. This study aimed to investigate the potential of rhizobacteria (isolated from various crop types) to encourage wheat growth by immobilization in alginate beads. The PGPR, obtained from different rhizospheric soils, were identified based on their colony morphology and biochemical characteristics. In addition, they were evaluated for their ability to produce indole-3-acetic acid (IAA), hydrogen cyanide (HCN), ammonia (NH3), and siderophores. The 16S rRNA-based identification revealed that auxin-producing rhizobacterial strains showed homology to various genera, including Bacillus, Brevundimonas, and Exiguobacterium spp. Selected strains showed plant growth-promoting (PGP) attributes and hydrolytic enzyme-producing abilities. Most of the strains had multifaceted plant growth-promoting attributes. Growth potential, assessed under laboratory and natural environments, confirmed the efficacy of bacterial strains as alginate beads biofertilizers. Encapsulation with alginate beads showed a 70-80% improvement in seed germination and a 60-70% enhancement in root and shoot length than control. The results revealed that the selected strain can be used as biofertilizers. Screening and the application of efficient PGPR encapsulation with alginate beads can be a better option to promote the production and yield of wheat.