Identification of Rhizosphere Bacterial Diversity with Promising Salt Tolerance, PGP Traits and Their Exploitation for Seed Germination Enhancement in Sodic Soil

The present research was carried to explore bacterial diversity in rhizosphere of salt tolerant rice and wheat genotypes cultivated in sodic soils and examined for the plant growth promoting traits, seed germination and vigor index of wheat in salt affected soils of pH > 9.30. Soil was collected and analyzed for physico-chemical properties using standard methods. Valuable bacterial population was isolated from the rhizosphere of salt tolerant rice and wheat varieties grown in salt affected sodic soils of Uttar Pradesh, India. Isolates were tested for PGP traits, NaCl uptake and tolerance at varying concentration (0.5, 5.0, 7.5, 10.0%). Bacterial isolates possessing high salt tolerance and PGP traits were selected for molecular identification and further exploited for the seed germination in wheat. On the basis of partial sequencing of 16S rRNA gene in nine potential isolates were confirmed as Pseudomonas sp., Agromyces tropicus, Lysinibacillus fusiformis, Bacillus flexus, Lysinibacillus sp., Bacillus tequilensis, Bacillus licheniformis, Pseudomonas mendocina and Bacillus licheniformis, respectively. The Lysinibacillus sp. was most effective in terms of improving seed germination percent (83%), shoot length (20.3 cm), fresh (0.41 g) and dry weight (0.057 g), and seedlings vigor index I (2056.2) and II (6.2). On the other side, root growth (length, fresh and dry weight) was found significantly higher with the inoculation of Lysinibacillus fusiformis. Salt tolerant PGPR of this study could be useful for the reclamation of saline/sodic soils concomitant with improved plant growth and yield.