Molecular Characterization of Endophytic Bacteria Isolated from Root of Different Field Crops

Plant associated bacteria that live inside plant tissues without causing any harm to plants are defined as endophytic bacteria. Endophytes were successfully isolated from root of different field crops and characterized based on their morphological and biochemical characters. The biochemical parameters viz., IAA production and phosphate solubilisation were studied from endophytic isolates. The results showed that IAA production ranged from highest 9.16 ìM.ml⁻¹ (eb-6; chick pea) to lowest 0.47 ìM.ml⁻¹(eb-7; pearl millet). All endophytes solubilised phosphate. RAPD polymorphism was carried out from ten endophytes isolated from field crops. Out of 50, total 12 RAPD primers showed polymorphism which generated 119 bands having 97.5% polymorphism with an average of 9.92 bands per primer. Among the screened primers OPA-13, OPA-16, OPB-11, OPC-04, OPD-07, OPF-09, OPJ-06, OPM-12 and OPP-13 demonstrated 100% polymorphism. RAPD analysis using random primers showed presence of high level of polymorphism. The calculated PIC values were ranged from 0.726 to 0.905. On the basis of PIC value, primer OPC-13 gave best results for characterization of endophytic isolates. The dendrogram generated three main clusters that consisted all the endophytes grouped together in their respective sub-cluster. Isolates derived from cluster bean (eb-1) and chick pea (eb-6) is most diverse in RAPD cluster analysis which also showed better IAA production and phosphate solubilisation activities.