scholarly journals Evaluation of thermotolerant rhizobacteria for multiple plant growth promoting traits from pigeonpea rhizosphere

2018 ◽  
Vol 10 (1) ◽  
pp. 518-521 ◽  
Author(s):  
Ritika Modi ◽  
Veena Khanna

In pigeonpea due to the prevailing high temperature, poor nodulation have usually been observed as a limiting factor in its productivity. Plant growth promoting traits of 5 pigeonpea rhizobacterial isolates out of 32, selected on the basis of maximum growth at 30, 40 and 50°C, were evaluated for their potential application in enhancing symbiosis and plant growth of pigeonpea. The level of IAA at 30, 40 and 50°C varied from 0.95-20.96 μg/ml, 1.21- 34.82 μg/ml and 0.16-17.34 μg/ml in the presence of tryptophan respectively. Maximum flavonoid production and siderophore production was recorded bacterial isolates with S12p6 (6.68 μg/ml) at 30°C and S1p1 (4.2 cm) at 40°C respectively. Isolates S1p1 and S12p6 showed relatively superior production of growth hormone, flavonoid-like compounds and siderophores can further be tested as co-inoculant with recommended Rhizobium for studying their efficacy under field conditions for symbiotic parameters and growth of pigeonpea.

2017 ◽  
Vol 9 (2) ◽  
pp. 920-923
Author(s):  
Gurmeet Kaur ◽  
Veena Khanna

PGPR strains exhibiting optimum functional traits at high temperature and are compatible with Rhizobium can be used in pigeonpea as biofertilizer. A total of 45 rhizobacterial isolates were isolated from 13 different locations of pigeonpearhizospheric soil of Punjab. Out of the 45 isolates, 5 isolates selected on the basis of maximum growth at 30°C and 40°C were morphologically and biochemically characterized, belonging to genera Pseudomonas (P-6, P-9) and Bacillus (P-30, P-31, P-32). Selected isolates were further evaluated for the production of IAA, GA, SA and flavonoids. IAA production was estimated in the range from 0.45-25.13 μg/ml and 4.62-34.34 μg/ml in the presence of tryptophan at 30 and 40°C respectively. Maximum gibberellic acid production was recorded with P-30 (108.99 μg/ml and 112.12 μg/ml) at 30 and 40°C respectively. Similarly maximum salicylic acid was also estimated with P-30 (157.2 μg/ml) followed by P-31 (141.0 μg/ml) at 40°C. All the isolates were also found to produce flavonoids ranged from 2.98 - 4.40 μg/ml at 40 °C. Isolates P-30, P-31 showed superior production of growth hormones and flavonoid-like compounds can further be tested under the field conditions to enhance growth and yield of pigeonpea.


2018 ◽  
Vol 64 (4) ◽  
pp. 253-264 ◽  
Author(s):  
Yanlei Zhu ◽  
Xiaoping She

The objective of this study was to assess the plant-growth-promoting abilities of 45 endophytic bacterial isolates from Ammodendron bifolium through physiological characteristics detection and endophytic bacteria–plant interaction. Each of these isolates exhibited 1 or more plant-growth-promoting traits, but only 11 isolates belonging to the genera Bacillus, Staphylococcus, and Kocuria were capable of promoting seed germination and radicle growth. These results together with the results of the correlation analysis revealed that the completion of seed germination may not be due to IAA production, phosphate solubilization, pellicle formation, and ACC deaminase, protease and lipase production by endophytic bacteria, but may be closely related to amylase and cellulase production. Further, endophytic bacterial isolates with plant-growth-promoting traits may also provide beneficial effects to host plants at different growth stages. Thus, these results are of value for understanding the ecological roles of endophytic bacteria in host plant habitats and can serve as a foundation for further studies of their potential in plant regeneration.


2020 ◽  
Vol 10 (2) ◽  
pp. 44-53
Author(s):  
Sana Shakeel ◽  
Ifrah Javaid ◽  
Ambreen Ahmed

Background: Rhizosphere is a soil region closest to roots of the plants inhabiting different types of microorganisms including rhizobacteria. Chemical fertilizers which are conventionally used for increasing crop production are dangerous in terms of minimizing the nutritional value of crops and may also be hazardous for biological agents. Therefore, the use of Plant Growth Promoting Rhizobacteria (PGPR) are favorable for improved crop production over chemical fertilizers. Objectives: The current study highlights the growth promoting traits of bacterial isolates through isolation of rhizospheric bacterial strains from different plants. Methodology: In this study, ten rhizospheric bacterial isolates were used, which were morpho-physiologically characterized and then tested for plant growth-promoting traits i.e., HCN production, ammonification and auxin production. Most of the bacterial strains gave positive results for these plant growth-promoting traits. To study the beneficial effects of these bacteria on plants, plant-microbial interaction assay was conducted using Zea mays. Results: Results revealed that these bacteria enhanced the growth as compared to control plants. Bacterial isolates Streptomyces lydicus (Cn6), Staphylococcus aureus (Cn7) and Bacillus pumilus (PP3) showed strong ammonia producing effects. The isolates Bacillus subtilis (Cn2), PP2 and PP5 exhibited strong potential of HCN production whereas only Streptomyces lydicus (Cn6) and Bacillus pumilus (PP3) were observed to be auxin producers. A maximum increase in fresh weight of the plants was observed in treatment with PP2 showing 94.36% increase over controls. Cn1 showed an increase (26.12%) in shoot length while Cn5 revealed a prominent increase (64.95%) in root length compared to the control plant. The isolates Cn5 and Cn4 showed improvement in the total chlorophyll content of the treated plants with a percentage increase of 100% and 99.82%, respectively compared to the control. Conclusion: In conclusion, these PGPR may be further used in agriculture research for growth improvement.


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