International Journal of Agriculture, Environment & Biotechnology
Citation: IJAEB: 7(4): 747-757 December 2014
DOI Number: 10.5958/2230-732X.2014.01383.7
©2014 New Delhi Publishers. All rights reserved
In vitro evaluation of plant growth regulators on tissue
culture bioassay produced by Pseudomonas species
Shweta Sharma* 1 , Mohinder Kaur 1 , Dinesh Kumar Srivastva 2 and
Geetika Gambhir 2
1 Department of Basic Science (Microbiology), Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni-Solan-173230, India.
2 Department of Biotechnology, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni-Solan-173230, India.
*Corresponding author:
Paper No. 264
Received: 10 July, 2014
Accepted: 15 November, 2014
Published: 18 December, 2014
Fluorescent Pseudomonas sp. is emerging as largest and potentially most promising group of PGPR
(plant growth promoting rhizobacteria) that are involved in plant growth enhancement. Plant growth
regulators viz., auxins, cytokinins and gibberellins help in plant growth and development. In present
study, fluorescent Pseudomonas strains isolated from rhizospheric soil from temperate fruit zone of
Himachal Pradesh were investigated for plant growth regulator production i.e. auxins, gibberellins and
cytokinins in nutrient broth. All the strains tested produced plant growth regulators in concentrations
auxins (1.83-21μg/ml), gibberellins (116.1-485.8μg/ml) and cytokinins (45.4-295.4μg/ml). Two strains
(An-1-kul and An-13-kul) were selected on the basis of over all PGPR activities for production of growth
regulators. Molecular characterization of best selected Pseudomonas strains were done by 16S-rRNA
technique. Plant growth regulators produced by best isolates were further studied to observe their effect
on growth of callus formation, shoot formation of broccoli and root elongation of cabbage
In recent study we evaluated that partially purified cytokinins and auxins extracted from Pseudomonas
aeruginosa showed maximum callus formation and shoots regeneration in broccoli cotyledon explants in
vitro developed shoots and development of roots at concentration of 2.0mg/l.
Keywords: Plant growth regulators, auxins, gibberellins, cytokinins, PGPR, Callus formation, root
Fluorescent Pseudomonads are considered to
of temperate fruit growing zone (apple and pear
promote plant growth directly and indirectly and
orchards) appear to have greater potential to
kept under plant growth promoting rhizobacteria
synthesize and release auxins, gibberellins and
(PGPR) group. PGPR can exhibit a variety of
cytokinins as secondary metabolites and these are
characteristics responsible for influencing plant
responsible for pronounced effect on plant growth
growth. The common traits include production
and development. Plant growth regulators are the
of plant growth regulators (auxins, gibberellins,
organic substances that influence physiological
cytokinins etc.), siderophore, HCN and antibiotics
processes of plants at very low concentrations
( Arshad and Frankenberger, 1992; Ahad et al.,
when produced endogenously by plants, they are
2012). Microorganism isolated from the rhizosphere
referred to as phytohormones (plant hormones),