Dixit et al.

numerous genera of both Gram-negative and Gram-positive species. Genera such

as Bacillus , Enterobacter , Klebsiella , Rhizobium , Pseudomonas , Burkholderia ,

Pantoea , Agrobacterium , Methylobacterium constitute the endophytes commonly

isolated from various leguminous and non-leguminous plants (Bacon and Hinton,

2006). Endophytic bacteria produce unusual secondary metabolites of plant

importance (Taechowisan et al ., 2005) thus they have an excellent potential to

be used as plant growth promoters for legumes and non-legumes (Antoun et

al ., 1998; Bai et al ., 2002). The direct promotion by endophytic bacteria entails

either synthesis of plant growth promoting substance or facilitating the uptake

of certain plant nutrients from the environment. The indirect promotion of plant

growth occurs when endophytic bacteria lessen or prevent the deleterious effect

of one or more phytopathogenic micro-organisms. Although exact mechanisms

by which plant growth promoting rhizobacteria (PGPR) promote plant growth are

not fully understood, but the activities of PGPR includes: the ability to produce

or change the concentration of plant growth regulators like indole acetic acid,

gibberellic acid, cytokinins and ethylene (Arshad and Frankenberger, 1993; Glick,

1995), symbiotic N ₂ fixation (Boddey and Dobereiner, 1995), antagonism against

phytopathogenic microorganisms by production of siderophores (Scher and Baker,

1982), antibiotics (Shanahan et al ., 1992) and cyanide (Flaishman et al., 1996),

solubilization of mineral phosphates and other nutrients (Gaur, 1990; De Freitas

et al ., 1997).

The endophytic bacteria are known to show either synergism or antagonism among

them. Interactions among endophytes influencing the plant productivity have been

explained extensively. Some of the rhizobial isolates have been reported to display

synergistic interaction with Pseudomonas (Dubey and Gupta, 2012).

Lentil ( Lens culinaris Medik.) is one of the important rabi pulse crop of India,

which is cultivated in the different states. It suffers from several microbial

diseases including wilt diseases caused by Fusarium oxysporum. Exploitation of

antagonistic endophytic bacteria for plant growth promotion and biocontrol of

phytopathogens has earlier been attempted (Kumar et al., 2011, 2012; Nejad and

Johnson, 2000). The present work was aimed at the isolation, characterization

and identification of plant growth promoting and antagonistic endophytic bacteria

from Lens culinaris and their exploitation for enhanced production and protection

in future.

material and methods

Sample collection

Sample of Lens culinaris (20-30 days) were collected from seven districts viz ,

Jhansi, Kanpur, Lucknow and Varanasi (Uttar Pradesh) India, during November –

December, 2011. These fields were never been inoculated with any bioinoculants.

96

Int. J. Bioinformatics and Biological Sci.: v.2 n.1&2, p. 95-109. March & June 2014