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

2021 ◽  
Vol 3 ◽  
Author(s):  
S. Sharath ◽  
S. Triveni ◽  
Y. Nagaraju ◽  
P. C. Latha ◽  
B. Vidyasagar

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.

2021 ◽  
Vol 3 ◽  
Author(s):  
Yalavarthi Nagaraju ◽  
Mahadevaswamy ◽  
Nagaraj M. Naik ◽  
S. B. Gowdar ◽  
K. Narayanarao ◽  
...  

In this study, a total of 50 halophilic bacterial isolates were screened for 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, of these six with the highest ACC deaminase activity were selected for an increase in chickpea yield under salinity. The ACC deaminase activity among the isolates was ranged between 0.12 and 3.56 mM α-KB mg−1 min−1. These six isolates and one reference strain from the Agricultural College, Raichur, were used in the microcosm experiment during the rabi season of 2018. After 60 days of sowing, decreased rhizosphere pH and electrical conductivity (EC) from 8.4 to 7.6 and 4.3 to 3.4 dS m−1, respectively, were reported in chickpea. Among the treatments, Bacillus safensis (B. safensis)-inoculated plants showed a higher number of flowers (71 flowers/plant), pods (49.3 pods/plant), branches (33.3 branches/plant), and enhanced fresh weight (17.2 g/plant) and dry weight (8.1 g/plant). They were corroborated by improved nitrogen and phosphorus absorption of 71.5 and 43.5%, respectively, in B. safensis-treated plants. Based on the microcosm experimental findings, three cultures improving biometric and yield attributes were chosen for the field investigation. The field study was carried out at the Agricultural Research Station, Ganagavathi, during Kharif 2019. The chickpea plants treated with the consortium [B. safensis, Pseudomonas stutzeri, and Staphylococcus xylosus] increased the superoxide dismutase and catalase activity of plants by 258 and 196%, respectively. In addition, an increase in ascorbate peroxidase activity (0.41 μmol of ascorbate oxidized s−1 g−1 fresh weight) in the leaves and proline content was also recorded. The consortium (B. safensis, P. stutzeri, and S. xylosus) significantly increased nutrient uptake (N and P), the number of flowers, number of pods, and yield by 63.26, 39.03, 110, 59.96, and 17.56%, respectively, in chickpeas. Finally, inoculation with a mixture of three isolates is an effective method for increasing chickpea production under osmotic stress.


2020 ◽  
Vol 51 (4) ◽  
pp. 1001-1014
Author(s):  
Sulaiman & Sadiq

The experiment was conducted in a greenhouse during 2017 and 2018 growing seasons to evaluate the impact of the shading and various nutrition programs on mitigating heat stress, reducing the use of chemical minerals, improving the reproductive growth and yield of tomato plant. Split-plot within Randomized Complete Block Design (RCBD) with three replications was conducted in this study. Shading factor was allocated in the main plots and the nutrition programs distributed randomly in the subplots. Results indicate that shading resulted in the decrease of daytime temperature by 5.7˚C as an average for both seasons; thus a significant increasing was found in leaf contents of macro nutrients (Nitrogen, Phosphorous, and Potassium), and micro nutrients (Iron, Zinc and Boron), except the Iron content in 2018 growing season. Furthermore, shading improved significantly the reproductive growth and tomato yield. Among the plant nutrition programs, the integrated nutrient management (INM) including the application of organic substances, bio inoculum of AMF and 50% of the recommended dose of chemical fertilizers; lead to the enhancement of nutrients content, reproductive characteristics and plant yield. Generally, combination of both shading and INM showed positive effects on plants nutrient status and persisting balance on tomato flowering growth and fruits yield.


2017 ◽  
Vol 9 (3) ◽  
pp. 1310-1316
Author(s):  
Gurjot Kaur ◽  
Poonam Sharma ◽  
Deepika Chhabra ◽  
Kailash Chand ◽  
Gurjit Singh Mangat

The present investigation was carried out to exploit bacterial endophytes associated with root and leaf tissue of rice plant for plant growth promotion (PGP) and colonization study in vitro. Total 10 endophytic bacterial isolates (Pseudomonas sp.) were evaluate for PGP traits like P solubilization, production of Indole acetic acid (IAA), siderophore, ACC deaminase, protease, cellulase, fluorescent pigment, urease and denitrification activity. Out of 10 endophytic bacteria 30 %, 60 %, 20 %, 70 %, 10 % and 10 % were positive for siderophore, protease, cellulase, fluorescent pigment, urease and denitrification respectively. Maximum IAA production was recorded with isolate LRBLE7 (18.8 μgml-1) followed by LRBRE4 (16.0 μgml-1) and maximum P-solubilization was recorded with isolate LRBRE4 (5.8 mg 100 ml-1) followed by LRBLE7 (4.4 mg 100 ml-1). ACC deaminase production was recorded with isolate LRBLE6 (O.D=0.352 nm) followed by LRBRE5 (O.D=0.324nm). Three potential isolates (LRBRE4, LRBRE6 and LRBLE7) were selected on the basis of multiple PGP traits and were subjected to colonization study of rice seedling in vitro. Potential bacterial isolates can be exploited for improving growth and productivity in rice under sustainable management system.


2019 ◽  
Vol 11 (2) ◽  
pp. 346-351
Author(s):  
Deepika Chhabra ◽  
Poonam Sharma

Bacteria that colonize plant tissues other than rhizobia and are beneficial for plant growth referred to non rhizobial plant growth-promoting endophytic bacteria (PGPEB). This study was designed to assay the biocontrol activity of plant growth promoting endophytic bacterial isolates those found positive for P. solubilization, ACC deaminase, Indole acetic acid and Gibberelic acid production. These bacterial isolates were obtained from chickpea (Cicer arietinum L.) tissues (roots and nodules).  In a previous study a total of 263 non rhizobial endophytic bacterial isolates were isolated. Out of 263 isolates, 64.5% and 34.5% were Gram positive and negative, respectively. Further for biochemical characterization, catalase, oxidase, citrate utilization, nitrate reduction, methyl red and Voges Proskauer’s tests, were performed. On the basis of P solubilization, ACC deaminase, Indole acetic acid and Gibberelic acid production 75 potential isolates were selected and screened for their biocontrol activity viz. (production of cell wall degrading enzymes, production of HCN and fluorescent pigment). Out of 75 isolates, only 29 isolates produced cellulase, 64 isolates were able to produce protease and 28 were positive for both cellulose and protease. Of 75 endophytic isolates 12 isolates (7 from root tissue and 5 from nodules tissue, respectively) were positive for HCN production and 16 isolates were found to be fluorescent pigment producer under µv ligh. As chemical fertilizers and pesticides have detrimental effects on the environment. So these bacterial endophytic isolates will be used not only as a biofertilizer because of their plant growth promotional activities but also used as an alternative of synthetic chemicals for control of several plant diseases.


Author(s):  
Saeed Banawas ◽  
Ahmed Abdel-Hadi ◽  
Mohammed Alaidarous ◽  
Bader Alshehri ◽  
Abdul Aziz Bin Dukhyil ◽  
...  

Cell phones may be an ideal habitat for colonization by bacterial pathogens, especially in hot climates, and may be a reservoir or vehicle in transmitting nosocomial infections. We investigated bacterial contamination on cell phones of healthcare workers in three hospitals in Saudi Arabia and determined antibacterial resistance of selected bacteria. A questionnaire was submitted to 285 healthcare workers in three hospitals, and information was collected on cell phone usage at the work area and in the toilet, cell phone cleaning and sharing, and awareness of cell phones being a source of infection. Screening on the Vitek 2 Compact system (bioMérieux Inc., USA) was done to characterize bacterial isolates. Of the 60 samples collected from three hospitals, 38 (63.3%) were positive with 38 bacterial isolates (4 Gram-negative and 34 Gram-positive bacteria). We found 38.3% of cell phones were contaminated with coagulase-negative staphylococci, particularly Staphylococcus epidermidis (10 isolates). Other bacterial agents identified were S. aureus, S. hominis, Alloiococcus otitis, Vibrio fluvialis, and Pseudomonas stutzeri. Antimicrobial susceptibility testing showed that most coagulase-negative staphylococci were resistant to benzylpenicillin, erythromycin, and rifampicin. Eight isolates were resistant to oxacillin, specifically S. epidermidis (3), S. hominis (2), and S. warneri (2). A. otitis, a cause of acute otitis media showed multidrug resistance. One isolate, a confirmed hetero-vancomycin intermediate-resistant S. aureus, was resistant to antibiotics, commonly used to treat skin infection. There was a significant correlation between the level of contamination and usage of cell phone at toilet and sharing. Our findings emphasize the importance of hygiene practices in cell phone usage among healthcare workers in preventing the transmission of multidrug-resistant microbes.


Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 343 ◽  
Author(s):  
Muhammad Zafar-ul-Hye ◽  
Subhan Danish ◽  
Mazhar Abbas ◽  
Maqshoof Ahmad ◽  
Tariq Muhammad Munir

Drought stress retards wheat plant’s vegetative growth and physiological processes and results in low productivity. A stressed plant synthesizes ethylene which inhibits root elongation; however, the enzyme 1-Aminocyclopropane-1-Carboxylate (ACC) deaminase catabolizes ethylene produced under water stress. Therefore, the ACC deaminase producing plant growth promoting rhizobacteria (PGPR) can be used to enhance crop productivity under drought stress. Biochar (BC) is an organically active and potentially nutrient-rich amendment that, when applied to the soil, can increase pore volume, cation exchange capacity and nutrient retention and bioavailability. We conducted a field experiment to study the effect of drought tolerant, ACC deaminase producing PGPR (with and without timber waste BC) on plant growth and yield parameters under drought stress. Two PGPR strains, Agrobacterium fabrum or Bacillus amyloliquefaciens were applied individually and in combination with 30 Mg ha−1 BC under three levels of irrigation, i.e., recommended four irrigations (4I), three irrigations (3I) and two irrigations (2I). Combined application of B. amyloliquefaciens and 30 Mg ha−1 BC under 3I, significantly increased growth and yield traits of wheat: grain yield (36%), straw yield (50%), biological yield (40%). The same soil application under 2I resulted in greater increases in several of the growth and yield traits: grain yield (77%), straw yield (75%), above- and below-ground biomasses (77%), as compared to control; however, no significant increases in chlorophyll a, b or total, and photosynthetic rate and stomatal conductance in response to individual inoculation of a PGPR strain (without BC) were observed. Therefore, we suggest that the combined soil application of B. amyloliquefaciens and BC more effectively mitigates drought stress and improves wheat productivity as compared to any of the individual soil applications tested in this study.


Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 226-234 ◽  
Author(s):  
Frank L. Young ◽  
Donald L. Wyse ◽  
Robert J. Jones

Field studies were conducted to evaluate the effect of quackgrass [Agropyron repens(L.) Beauv. ♯ AGRRE] density and soil moisture on corn (Zea maysL.) growth and yield. Quackgrass densities ranging from 65 to 390 shoots/m2reduced corn yield 12 to 16%. A quackgrass density of 745 shoots/m2reduced corn yields an average of 37% and significantly reduced corn height, ear length, ear-fill length, kernels/row, rows/ear, and seed weight. In the soil moisture study, quackgrass was shorter than corn throughout the growing season, and analyses of corn leaf tissue indicated that quackgrass did not interfere with the nutrient status of the corn. In 1979, soil moisture was not limiting and corn yields were similar in all treatments regardless of irrigation or the presence of quackgrass. In 1980, soil moisture was limited and irrigation increased the yield of quackgrass-free corn. Irrigation also increased the yield of quackgrass-infested corn to a level similar to irrigated corn. When light and nutrients are not limiting factors, an adequate supply of soil moisture can eliminate the effects of quackgrass interference on the growth, development, and yield of corn.


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