Characterization of Multiple Plant Growth Promoting Traits of Serratia Spp. Associated With Vegetables Rhizospheric Soil

The rhizosphere zone of 1-2 mm around plant roots is rich in nutrients and provides niches different from those in bulk soil for bacteria to thrive. Plant growth promoting rhizobacteria (PGPR) are known to influence plant growth by various direct or indirect mechanisms. The current research assessed the plant growth promoting (PGP) potential of Serratia spp isolated from the fields growing horticultural crops of the rhizosphere of 6 different crops viz. , eggplant, cabbage, ladies finger, tomatoes, green chili and pea plants from both Namakkal and Erode districts of Tamil Nadu state.45 soil samples were collected from the rhizospheric soil of vegetable plants and Ten isolates of Serratia spp were isolated. IAA production was shown in all the isolates of Serratia spp (100 %). Ser 1, 4 and 9 produced the highest level of IAA as compared to other isolates while Ser 2, 3, 7 and 8 produced moderate amount of IAA. All the isolates produced yellow color indicating their ability to produce ammonia. For all the ten isolates, HCN production was seen in Ser 1, 4, 5, 7 and 10 while the rest produced little or no significant amounts of HCN. The formation of clear zones on the medium was an indication of phosphate solubilization. The isolates exhibited more than one PGP trait which may promote plant growth directly or indirectly or synergistically. The results provide insights into biotechnological approaches to using PGPR as an alternative to chemicals.