scholarly journals Effects of Plant Growth Promoting Rhizobacteria (PGPR) on <i>In Vitro</i> Bread Wheat (<i>Triticum aestivum</i> L.) Growth Parameters and Biological Control Mechanisms

2016 ◽  
Vol 06 (09) ◽  
pp. 677-690 ◽  
Author(s):  
Benderradji Laid ◽  
Kellou Kamel ◽  
Ghadbane Mouloud ◽  
Salmi Manel ◽  
Saibi Walid ◽  
...  
2017 ◽  
Vol 107 (8) ◽  
pp. 928-936 ◽  
Author(s):  
Ke Liu ◽  
Molli Newman ◽  
John A. McInroy ◽  
Chia-Hui Hu ◽  
Joseph W. Kloepper

A study was designed to screen individual strains of plant growth-promoting rhizobacteria (PGPR) for broad-spectrum disease suppression in vitro and in planta. In a preliminary screen, 28 of 196 strains inhibited eight different tested pathogens in vitro. In a secondary screen, these 28 strains showed broad spectrum antagonistic activity to six different genera of pathogens, and 24 of the 28 strains produced five traits reported to be related to plant growth promotion, including nitrogen fixation, phosphate solubilization, indole-3-acetic acid production, siderophore production, and biofilm formation. In advanced screens, the 28 PGPR strains selected in vitro were tested in planta for biological control of multiple plant diseases including bacterial spot of tomato caused by Xanthomonas axonopodis pv. vesicatoria, bacterial speck of tomato caused by Pseudomonas syringae pv. tomato, damping-off of pepper caused by Rhizoctonia solani, and damping-off of cucumber caused by Pythium ultimum. In all, 5 of the 28 tested strains significantly reduced three of the four tested diseases, and another 19 strains showed biological control to two tested diseases. To understand the observed broad-spectrum biocontrol capacity, antiSMASH was used to predict secondary metabolite clusters of selected strains. Multiple gene clusters encoding for secondary metabolites, e.g., bacillibactin, bacilysin, and microcin, were detected in each strain. In conclusion, selected individual PGPR strains showed broad-spectrum biocontrol activity to multiple plant diseases.


Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 774-784 ◽  
Author(s):  
Ni Xiang ◽  
Kathy S. Lawrence ◽  
Joseph W. Kloepper ◽  
Patricia A. Donald ◽  
John A. McInroy ◽  
...  

In the past decade, increased attention has been placed on biological control of plant-parasitic nematodes using various fungi and bacteria. The objectives of this study were to evaluate the potential of 662 plant growth-promoting rhizobacteria (PGPR) strains for mortality to Meloidogyne incognita J2 in vitro and for nematode management in greenhouse, microplot, and field trials. Results indicated that the mortality of M. incognita J2 by the PGPR strains ranged from 0 to 100% with an average of 39%. Among the PGPR strains examined, 212 of 662 strains (or 33%) caused significantly greater mortality percent of M. incognita J2 than the untreated control. Bacillus was the major genus initiating a greater mortality percentage when compared with the other genera. In subsequent trials, B. velezensis strain Bve2 reduced M. incognita eggs per gram of cotton root in the greenhouse trials at 45 days after planting (DAP) similarly to the commercial standards Abamectin and Clothianidin plus B. firmus I-1582. Bacillus mojavensis strain Bmo3, B. velezensis strain Bve2, B. subtilis subsp. subtilis strain Bsssu3, and the Mixture 2 (Abamectin + Bve2 + B. altitudinis strain Bal13) suppressed M. incognita eggs per gram of root in the microplot at 45 DAP. Bacillus velezensis strains Bve2 and Bve12 also increased seed-cotton yield in the microplot and field trials. Overall, results indicate that B. velezensis strains Bve2 and Bve12, B. mojavensis strain Bmo3, and Mixture 2 have potential to reduce M. incognita population density and to enhance growth of cotton when applied as in-furrow sprays at planting.


Author(s):  
Thanh Nguyen Chu ◽  
Nhi Yen Nguyen ◽  
Diep Ngoc Dao ◽  
Bao Thi Hoai Tran ◽  
Minh Thi Thanh Hoang ◽  
...  

Plant growth promoting rhizobacteria (PGPR) are free-living soil bacteria (rhizosphere bacteria), rhizoplane bacteria or endophytic bacteria that may promote plant growth and suppress plant diseases. The aim of this study is to evaluate effects of 2 rhizobacteria strains belonging to the genus Pseudomonas isolated from maize rhizosphere on the plant growth promotion. The in vitro tests showed that both of strain could fix nitrogen, solubilize phosphate, produced phytohormones (IAA and GAs), and improved the germination and growth of Arabidopsis thaliana. Under the greenhouse condition, growth parameters of bacteria inoculated maizes (fresh weight of shoot, dry weight of root, chlorophyll content) were also increased significantly than those of uninoculated ones. Our results reported 2 promising bacteria strain candidates and revealed their potential as a biological agent for eco-friendly agricultural practices.


The Analyst ◽  
2021 ◽  
Author(s):  
Yuchen Zhang ◽  
Rachel Komorek ◽  
Jiyoung Son ◽  
Shawn Riechers ◽  
Zihua Zhu ◽  
...  

Plant growth-promoting rhizobacteria (PGPR) play a crucial role in biological control and pathogenic defense on and within plant tissues, however the mechanism(s) by which plants associate with PGPR to elicit...


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