In Vitro Screening of Salt Tolerant Bacillus from Rhizosphere of Tomato (Lycopersicon esculentum) Showing Plant Growth Promoting Traits

2015 ◽  
Vol 5 (12) ◽  
pp. 55-60 ◽  
Author(s):  
Yogendra Singh ◽  
Author(s):  
Shobana Narayanasamy ◽  
Sugitha Thankappan ◽  
Sivakumar Uthandi

To develop an osmotolerant microbe, as a bioinoculant to mitigate drought it is vital to understand the impact of osmotic stress on their growth and plant growth promoting functional traits. The present study was aimed to evaluate the physiological adaptations and plant growth-promoting traits of a phyllosphere bacterium Bacillus altitudinis FD48 under osmotic stress conditions. The FD48 strain isolated from rice (cultivar ADT43) phyllosphere obtained from Biocatalysts laboratory, Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore. In vitro bioassay was conducted to evaluate the osmotolerant potentials of FD48. B. altitudinis FD48 grown in LB supplemented with PEG 6000 and grown for 48 hrs. Physiological adaptation to osmotic stress was observed by assessing the osmolytes and free amino acids content produced by FD48 under induced stress. Further the plant growth promoting traits under osmotic stress also asceratined. The growth pattern of FD48 strain decreased with the increase in PEG concentrations. The lower level of osmotic stress enhanced the growth of FD48 but at higher concentration exhibited a decline in growth. Enhanced levels of IAA (25 µg g-1 of protein) and EPS (9.76 mg mg-1 protein) production were recorded in the FD48 strain at lower levels of osmotic stress. Furthermore, an increase in osmotic stress had a deleterious effect on IAA production and ACC deaminase activity while the exopolysaccharide production was enhanced. Growth of FD48 under osmotic stress also increased the accumulation of proline and compatible sugars that will protect the FD48 strain by maintaining the turgor potential of cells and stabilizes the membrane proteins. Hence, the results of our study suggesting that, B. altitudinis FD48 strain has the potential to tolerate osmotic stress and might be used as a newer bio-inoculant for triggering moisture deficit stress resilience in plants.


2015 ◽  
Vol 2 (1) ◽  
pp. 1-8
Author(s):  
Moonmoon Nahar Asha ◽  
Atiqur Rahman ◽  
Quazi Forhad Quadir ◽  
Md Shahinur Islam

A laboratory experiment was performed to isolate some native rhizobacteria that could be used as bioinoculants for sustainable crop production. A total of 43 rhizobacteria were isolated from undisturbed plant rhizosphere soils of three different locations of Bangladesh and evaluated their plant growth promoting traits, both direct and indirect. The study has screened out isolates on the basis of their phosphorous solubilization and nitrogen (N) fixation. The phosphate solubilization assay in National Botanical Research Institute of Phosphate (NBRIP) medium revealed that 12 bacterial isolates were able to solubilize tricalcium phosphate and the rhizobacteria M25 showed best performance with a PSI of 3.33 at 5 day. Exactly 47% (20 isolates) of the isolated rhizobacteria were able to grow in N-free Winogradsky’s medium, which is an indication of potential N2-fixers. Among the 20 potential N-fixers, 15 were able to grow within 24 hours of incubation indicating that they are more efficient in Nfixation. The present study successfully isolated and characterized 43 rhizobacteria. Some of these isolated rhizobacteria have potential plant growth promoting traits and are potential plant growth promoting rhizobacteria (PGPR) candidate. Considering all plant growth promoting traits, the isolate F37 was the best followed by M6. However, further experiments are needed to determine the effectiveness of these isolates under in vitro and different field conditions to understand the nature of interaction with the plant and environment.Res. Agric., Livest. Fish.2(1): 1-8, April 2015


2021 ◽  
Vol 15 (5) ◽  
pp. 253-261
Author(s):  
Henrique Gomes Lisboa Paulo ◽  
Henrique Marques de Andrade Paulo ◽  
Cristiane Machado Paula ◽  
Paiva de Sousa Cristina ◽  
Teixeira Lacava Paulo

Author(s):  
Sangita Sahni ◽  
Bishun Deo Prasad ◽  
Tushar Ranjan

Thirty well-characterized pseudomonad isolates for plant growth-promoting traits were screened for their antagonistic activities against 20 isolates of Sclerotium rolfsii. Out of the 30 pseudomonad isolates, PUR46 was found to be best against all 20 isolates of Sclerotium rolfsii, because of its unique ability to suppress the growth of mycelia as well as the sclerotia formation of most of the S. rolfsii isolates in vitro conditions. In our previous study, PUR46 was also found to be positive for growth promoting traits like phosphorus solubilization and ammonification. The results suggested that expression of one or more of the traits like antagonistic activity against S. rolfsii and solubilization of tri-calcium phosphate may help in controlling the pathogen besides enhancement of plant growth. In this study, our investigations clearly indicate that PGPR isolates PUR 46 may be exploited to be used as potential biocontrol agents against S. rolfsii in agriculture system.


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