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 and Warangal 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 0.13–0.40 mM of α-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.

Drought-Tolerant Bacteria and Arbuscular Mycorrhizal Fungi Mitigate the Detrimental Effects of Drought Stress Induced by Withholding Irrigation at Critical Growth Stages of Soybean (Glycine max, L.)

“…Bacterial isolates (Bradyrhizobia and Rhizobacteria) were grown on YEM and NB liquid media, respectively, and the media were supplemented by Polyethylene glycol (PEG) with a molecular weight of 6000 at a rate of 40 gm per liter [ 37 ]. Inoculation was carried out with 24 h-old isolates, incubated for 24 h at 30 °C, then 10 mL of each flask was taken, and the optical density (OD) was estimated by a spectrophotometer at 600 nm based on the following: less than 0.3, completely sensitive; between 0.3 and 0.39, sensitive-to-tolerant, 0.4 and 0.5, tolerant; greater than 0.5, completely tolerant [ 38 ].…”

“…Gibberellic acid (GA) was determined at 760 nm using a spectrophotometer by the method mentioned by Abou-Aly et al [ 40 ]. Exopolysaccharides (EPS) were determined after 72 h of incubation and calculated as mg/L, as described by Sharath et al [ 37 ]. Proline was determined in the bacterial supernatant by the ninhydrin colorimetric method [ 41 ].…”

Unexplored agronomic, socioeconomic and policy domains for sustainable cotton production on small landholdings: a systematic review

“…Symbiotic relationships with cotton roots are widely reported including Arbuscular mycorrhizal (AM) fungi that enhance nutrient uptake, especially phosphorus, by extending their hyphae into the soil and increasing the root's surface area for nutrient absorption (Pereg and McMillan, 2015). Nitrogen-fixing bacteria like rhizobia establish a symbiotic relationship with leguminous cover crops that are often intercropped with cotton (Saghafi et al, 2020;Sharath et al, 2021). These bacteria convert atmospheric nitrogen into a form that the plants can utilize, promoting soil fertility and reducing the need for synthetic fertilizers.…”