Isolation and molecular characterization of plant growth-promoting Bacillus spp. and their impact on sugarcane (Saccharum spp. hybrids) growth and tolerance towards drought stress

Dar GH, Sofi S, Padder SA, Aisha Kabli A. 2018. Molecular characterization of rhizobacteria isolated from walnut (Juglans regia) rhizosphere in Western Himalayas and assessment of their plant growth promoting activities. Biodiversitas 19: 662-669. The present study was aimed to isolate and characterize effective bacteria from the rhizosphere of walnut (Juglans regia) grown in North Western Himalayas and assess their growth promoting potential so that they may, in future, be exploited as biofertilizers. Based on preliminary screening of 98 bacterial isolates obtained from four walnut growing districts of Kashmir valley during survey in 2015, 12 isolates were characterized morpho-biochemically and molecularly basis. On the basis of 16S rDNA sequencing they were identified as Bacillus licheniformis WI 90, B. tequilensis WI 62, B. cereus WI 36, B. subtilis strains WI 63 and WI 65, Micrococcus luteus strains WI 12, WI 41 and WI 80; M. yunnanensis strains WI 60 and WI 30 and Micrococcus sp. strains WI 11 and WI 91. The assessment of these rhizobacteria for plant growth promoting attributes revealed that B. licheniformis WI 90 possessed higher phosphorus solubilization activity (312 mg/L), followed by Micrococcus sp. WI 91 (267 mg/L) while high siderophore was produced by M. luteus WI 12 (27.2% siderophore units), followed by B. licheniformis WI 90. B. cereus strains WI 36. High IAA contents (30 µg/mL) was yielded by WI 41, followed by M. yunnanensis WI 60 (28 µg IAA/mL) while higher and statistically at par gibberellic acid was produced by B. licheniformis WI 90, Micrococcus sp. WI 91 and M. luteus WI 80. Higher chitinase enzyme activity was observed in B. subtilis WI 63 (30.5 units/mL), followed by B. tequilensis WI 62 (25.3 units/mL) and B. subtilis WI 65 (25.1 units/mL). The study revealed high plant growth promoting potential in these rhizobacteria.

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Isolation screening and molecular characterization of zinc solubilizing bacteria and their effect on the growth of wheat (Triticum aestivum)

Asia Pacific Journal of Molecular Biology and Biotechnology ◽

10.35118/apjmbb.2021.029.2.09 ◽

2021 ◽

pp. 85-97

Author(s):

Vandana Nandal ◽

Manu Solanki

Keyword(s):

Triticum Aestivum ◽

Plant Growth ◽

Molecular Characterization ◽

Wheat Plant ◽

Chitinase Activity ◽

World Population ◽

Zinc Tolerance ◽

Plant Growth Promoting ◽

Growth Promoting

Wheat (Triticum aestivum) is a major cereal crop grown worldwide. Most of the world population depends on wheat for their nutrient requirement. Zinc (Zn) is one of the most crucial elements required for the development of wheat plant. It is one of the micronutrients required in many biochemical cycles. It has been found that the concentration of Zn is below the required level in the soil and hence it remains deficient in the crops. To ameliorate the deficit, chemical fertilizers are added in the soil, where as biofertilizers are preferred over chemicals in sustainable agriculture. The paper describes the isolation, screening and molecular characterization of the zinc solubilizing bacteria (ZSB) to improve plant growth. A total of 100 soil samples were collected from the rhizospheric soil of wheat plants. ZSB were isolated by dilution plating on Bunt and Rovira media. The 50 isolates were selected and screened for their Zn solubilization. The zinc tolerance of all the isolates varied from 0.5% to 2% of insoluble Zn. Based on the Zn tolerance ability, 15 bacterial isolates were screened for Phosphate solubilization and further analyzed for the synthesis of IAA, NH3, siderophore production and chitinase activity. The three isolates were selected on the basis of the plant growth promoting characteristics for molecular characterization and were found to be homologous to Bacillus cereus, Pseudomonas aeruginosa and Bacillus tropicus. This study documented the establishment and survival of ZSB in the wheat rhizosphere and enhanced plant productivity, thus indicating the potential of isolates as commercial biofertilizers.

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