Growth stimulation of clusterbean (Cyamopsis tetragonoloba) by coinoculation with rhizosphere bacteria and Rhizobium

Abstract

Clusterbean [Cyamopsis tetragonoloba (L.) Taub.] is an important commercially utilizable crop grown in arid zone of India. Microorganisms present in the rhizosphere of this crop produce various plant growth-promoting substances and enhance the availability of nutrients to the plants. Therefore, fifty five bacterial isolates obtained from the rhizosphere of clusterbean were explored for beneficial characteristics. Twenty rhizobacterial isolates produced indole acetic acid ranging from 3.9 to 24.7 µg/mL. Only six isolates HCS7, HCS19, HFS7, HFS9, HFS10 and HFS12 showed d-aminolevulinic acid production varying from 1.3 to 7.0 µg/mL. Fourteen isolates showed solubilization of potassium on mica containing Aleksandrov medium plates. Stimulation of root and shoot growth of clusterbean seedlings on water agar plates was observed by inoculation of eleven rhizobacterial isolates at 5 and 10 days of growth whereas some isolates showed stunting effect on the growth of shoot and root as compared to uninoculated seedlings. At 60 days of plant growth, inoculation of Bradyrhizobium strain GSA11 and Rhizobium strain GSA110 showed significant nodulation and their inoculation resulted in 141.94 and 151.43% gains in shoot dry weight, respectively under chillum jar conditions. Coinoculation of Bacillus isolate HCS43 with Rhizobium strain GSA110 formed 48 nodules/plant and plant dry weight was enhanced by 190.09% in comparison to uninoculated control plants.

Açaí palm seedling growth promotion by rhizobacteria inoculation

“…Potassium (K) is correlated with enzymatic activation, carbohydrate transport, and stomatal opening regulation [57]. The PGPRs may benefit plants through their ability of solubilizing potassium and make it available to the plant, therefore contributing to a higher growth [8,58], as observed in the present study, where inoculation of rhizobacteria induced K accumulation in leaves and positively influenced the growth of açaí palm seedlings. In rice plants inoculated with rhizobacteria, the higher potassium absorption efficiency contributed to higher roots and the aerial part growth [59].…”

“…Rhizobacteria are found in free-living in the soil and promote benefits to the plant through colonization of the root system [7]. The benefits include increased recycling, solubilization, and absorption of mineral nutrients, synthesis of vitamins, amino acids, siderophores, and plant growth, promoting hormones such as gibberellin, auxin, and cytokinin [8,9].…”

Screening and Characterization of Stress Tolerant Rhizobia From Different Soils of Telangana

“…Among five isolates, three isolates were moderate (++) in ACCd production (RR-1, WR-14), two isolates were weak (+) for ACCd production (GR-5, GNR-8, ASR-17). [18] reported similar results i.e fifty Mesorhizobium isolates were obtained from nodules of chickpea plants on yeast extract mannitol agar medium. Mesorhizobium isolates were screened for ACC utilization and growth at different salt concentrations in YEMA medium.…”

A Comprehensive Study on IAA production by Bradyrhizobium japonicum and Bacillus subtilis and Its Effect on Vigna radiata Plant Growth

“…Several researchers had reported that Bradyrhizobium sp. (Chaudhary and Sindhu, 2016;Ahemad and Khan, 2012;Shaharoona et al 2006) and Bacillus sp. (Saeid et al 2018) can produce HCN, Ammonia and siderophores and also solubilize phosphate by organic acid production.…”