The Role of Phyllosphere Bacteria in Improving Cotton Growth and Yield Under Drought Conditions

Abstract

Cotton is a valuable fiber and cash crop in Telangana, India. This study examines how crop growth and fiber yield are affected by the uneven distribution of rainfall. Cotton phyllosphere bacterial isolates were gathered from the Rangareddy andWarangal Districts of Telangana, and in total, 31 phyllosphere bacterial isolates were obtained. These isolates were screened for drought tolerance and it was found that fifteen suitable isolates grew at −1.25 Mpa stress level with copious amounts of exopolysaccharides production. These isolates were further screened for ACC deaminase production and we observed 0.13–0.40mM of a-ketobutyrate per milligram of cellular protein per hour. Five efficient bacterial isolates, namely Pseudomonas stutzeri, Acinetobacter sp., Bacillus mojavensis, Pseudomonas chlororaphis, and Enterobacter asburiae were found to produce ACC deaminase and were able to grow at −1.25 Mpa stress level. The cotton variety ADB-542 (drought susceptible) was treated with drought-tolerant five isolates. Acinetobacter sp. treated seeds had the highest seed germination and seedling vigor of 76.67 and 45.81%, respectively. The nutrient status of inoculated plots was considerably improved. The root length, fresh weight, proline content, and the number of bolls were increased by 28.52, 41.9, 28.78, and 12.99%, respectively, with the inoculation of Acinetobacter sp., to plants at −0.75 Mpa water potential. Overall the performance of cotton was improved significantly with the inoculation of phyllosphere bacteria to seeds; hence they can be recommended for the application of field crops as bio-inoculants.