scholarly journals Morphophysiological, Enzymatic, and Elemental Activity in Greenhouse Tomato Saladette Seedlings from the Effect of Plant Growth-Promoting Rizobacteria

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1008
Author(s):  
Tomás Juan Álvaro Cervantes-Vázquez ◽  
Ana Alejandra Valenzuela-García ◽  
María Gabriela Cervantes-Vázquez ◽  
Tania Lizzeth Guzmán-Silos ◽  
Erika Lagunes Fortiz ◽  
...  

The tomato is a widely cultivated and consumed vegetable globally. Comarca Lagunera is an important tomato-exporting region of Mexico. Salinity is an abiotic factor that reduces productivity and increases production costs. To advance growing period, there is high demand for the sustainable production of seedlings. Plant-growth-promoting rhizobacteria (PGPR) are characterized by improving plant growth through different mechanisms and can be an option for reducing the misuse of chemical fertilizers. The importance of the application of strains, evaluating various inoculation methods (in seed, soil, foliar spraying, and root immersion), should be evaluated to propose biofertilization packages in a specific crop. Thus, the study aimed to determine the effect of PGPR (Bacillus paralicheniformis, Acinetobacter guillouiae, Aeromonas caviae, and Pseudomonas lini) vs. nutrient solution and distilled water in the seedlings stage of saladette-type tomato on morphophysiological variables, nitrate reductase (NR) enzyme activity, and plant minerals via tissue analysis under greenhouse conditions. The four PGPR were inoculated by different methods (inoculation in seed, sprinkling, and both) in saladette-type tomato seedlings under greenhouse conditions and evaluated in vivo 40 days after sowing for morphophysiological variables, such as seedling height; stem diameter; root displaced volume; fresh and dry weight matter of the leaves, stems, and roots; leaf area; and nitrate reductase enzyme activity. The effect of the inoculation of PGPR showed significant results for Pseudomonas lini vs. the control, with 40% higher values, on average, for plant height, stem diameter, displaced root volume, and fresh weight of root, leaf, and stem. The response of enzymatic and mineral content in seedlings was variable with nutrient solution and significant with distilled water. Studies related to the promotion of plants in the subsequent phenological stages of a tomato, considering the selected PGPR, should be considered in future research.

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1449
Author(s):  
Dasun Premachandra ◽  
Lee Hudek ◽  
Aydin Enez ◽  
Ross Ballard ◽  
Steve Barnett ◽  
...  

Canola (Brassica napus L.) is the third largest crop produced in Australia after wheat and barley. For such crops, the variability of water access, reduced long-term annual rainfall and increasing water prices, higher overall production costs, and variability in production quantity and quality are driving the exploration of new tools to maintain production in an economical and environmentally sustainable way. Microorganisms associated with the rhizosphere have been shown to enhance plant growth and offer a potential way to maintain or even increase crop production quality and yield in an environmentally sustainable way. Here, seven bacterial isolates from canola rhizosphere samples are shown to enhance canola growth, particularly in low water activity systems. The seven strains all possessed commonly described plant growth promoting traits, including the ability to produce indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase, and the capacity to solubilise nutrients (Fe2+/3+ and PO43−). When the isolates were inoculated at the time of sowing in pot-based systems with either sand or clay loam media, and in field trials, a significant increase in dry root and shoot biomass was recorded compared to uninoculated controls. It is likely that the strains’ plant growth promoting capacity under water stress is due to the combined effects of the bacterial phenotypes examined here.


2008 ◽  
Vol 35 (2) ◽  
pp. 141 ◽  
Author(s):  
Josef Kohler ◽  
José Antonio Hernández ◽  
Fuensanta Caravaca ◽  
Antonio Roldán

This study examined the effect of inoculation with the plant-growth-promoting rhizobacterium (PGPR) Pseudomonas mendocina Palleroni, alone or in combination with an arbuscular mycorrhizal (AM) fungus, Glomus intraradices (Schenk & Smith) or Glomus mosseae (Nicol & Gerd.) Gerd. & Trappe, on antioxidant enzyme activities (superoxide dismutase, catalase and total peroxidase activities), phosphatase and nitrate reductase activities and solute accumulation in leaves of Lactuca sativa L. cv. Tafalla affected by three different levels of water stress. At moderate drought, bacterial inoculation and mycorrhizal inoculation with G. intraradices, alone or in combination, stimulated significantly nitrate reductase activity. At severe drought, fertilisation and P. mendocina inoculation, alone or in combination with either of the selected AM fungi, increased significantly phosphatase activity in lettuce roots and proline accumulation in leaves. Total peroxidase (POX) and catalase (CAT) activities increased in response to drought, whereas superoxide dismutase activity decreased. Inorganic fertilisation and both combined treatments of PGPR and AM fungus showed the highest values of leaf POX activity under severe drought. The highest CAT activity was recorded in the fertilised plants followed by the P. mendocina-inoculated plants grown under severe stress conditions. These results support the potential use of a PGPR as an inoculant to alleviate the oxidative damage produced under water stress.


Author(s):  
Shamal S. Kumar ◽  
Ananta G. Mahale ◽  
Md. Mifta Faizullah ◽  
J. Radha Krishna ◽  
Tharun K. Channa

Water scarcity is known as a major stumbling block towards crop development and its output all over the world. Certain free-living bacterial strains have been found near the plant root zones which have shown to improve resistance of plants towards water stress. Despite availability of basic nutrients, drought an abiotic factor substantially inhibits growth, development and yield of crops by causing an increase in ethylene levels. It is a good idea to incorporate the use of a management tool which is the utilization of plant growth-promoting rhizobacteria to help several crops manage drought conditions. Drought stress in crops can be alleviated by reducing ethylene synthesis, exopolysaccharide, osmoregulation, Indole-3-acetic acid and aggregation with the ACC deaminase-containing plant growth-promoting rhizobacteria. Inoculating pathogens like root rot (Macrophomina phaseolina) affected plant with Pseudomonas fluorescens strain TDK1 with ACC deaminase function improves drought stress. Using plant growth-promoting rhizobacteria to mitigate the negative imbibes of drought in most crops is a good idea. Several studies have been carried out on plant growth-promoting rhizobacteria, as its inoculation not only manages drought related conditions but increases root hair growth and lateral root, which assist in increased water and nutrient uptake. It limits ethylene supply, alternatively increases plant root growth by hydrolyzing 1-aminocyclopropane-1-carboxylic acid (ACC). This review will give us a perspective on the importance of plant growth-promoting rhizobacteria, as it is one of the efficient tools that helps manage drought stress on several crops.


2020 ◽  
Vol 19 (1) ◽  
pp. 97-105
Author(s):  
Gölgen Bahar Öztekin ◽  
Yüksel Tüzel

This study was conducted in order to determine the effects of oxygen enrichment of nutrient solution coupled with plant growth promoting rhizobacteria on soilless grown iceberg lettuce (cv. ‘Papiro’) production. Seeds were treated with Bacillus subtilis, Pseudomonas putida, P. fluorescens, P. punonensis and combined application of B. subtilis + P. fluorescens and were sown into vermicompost : peat (1 : 1.5, v/v) mixture on January 14th, 2015. After germination in growth chamber, seedlings were moved to a greenhouse for seedling growing till they were ready for planting. Seedlings were transplanted to the polyethylene greenhouse 35 days after sowing. Perlite as growing medium was used in open-system soilless culture. Nutrient solution was aerated with an air compressor and applied to plants 2 days after planting with drip irrigation. To diffuse oxygen into nutrient solution in large bubbles, a circular air-stone commonly used in fisheries was used. The nutrient solution without oxyfertigation and plants not treated with bacteria constituted the control treatment. Experiments were conducted in randomized plots design with 2 factors and 3 replications. Heads were harvested 2 months after transplanting. Yield and head quality parameters of head were determined. It was concluded that oxygen enrichment of nutrient solution through a compressor (aeration) provided increases in yield and plant growth. Especially root development, head size and leaf number were higher in plants grown with aerated nutrient solution. Among the tested bacteria, B. subtilis, P. fluorescens and B. subtilis + P. fluorescens were found promising due to the their higher performance under aerated conditions on greenhouse lettuce grown in perlite.


Author(s):  
Vijay Kumar ◽  
Indu Richa ◽  
Sahil Kumar ◽  
Diksha Sehajpal

The bacteria that colonize the plant's rhizosphere are known as PGPR. The rhizospheric region is the area under the ground surface that is linked with plant roots. PGPR bacteria are free-living bacteria that colonize plant roots and have positive impacts on plant growth. The objectives of this paper were to isolate and identify the most powerful PGPR, as well as to assess their efficacy in terms of P-solubilization, HCN generation, and lytic enzyme activity (protease). A total of 11 bacterial isolates were identified in the Hamirpur district of Himachal Pradesh. All isolates were tested for a variety of plant growth-promoting characteristics, including phosphate solubility, HCN production and protease production. On PVK agar, 8 of the 11 isolates tested positive for P-solubilization in the 5-20 mm zone. One bacterial isolate exhibited positive hydrogen cyanide activity in the event of HCN generation. In the case of lytic enzyme activity, 7 bacterial isolates were positive for protease production.


Author(s):  
João Pedro Alves de Aquino ◽  
Francisco Barbosa de Macedo Junior ◽  
Jadson Emanuel Lopes Antunes ◽  
Marcia do Vale Barreto Figueiredo ◽  
Francisco de Alcântara Neto ◽  
...  

ABSTRACT Plant growth-promoting bacteria (PGPB) are found in plant tissues and promote plant growth by secretion of hormones and enzymes, or by facilitating the nutrient uptake. This study assessed forty PGPB isolates to determine their effects on maize and sorghum growth. These isolates were also compared with uninoculated plants, as negative (-N; without N fertilization) and positive (+N; with N fertilization) controls. Plant height, stem diameter, shoot and root dry mass, leaf N accumulation and chlorophyll content were evaluated. For both the maize and sorghum, the height, stem diameter and shoot dry mass in plants inoculated with PGPB were similar to those of uninoculated plants supplied with N, and the responses for root mass were higher than in plants supplied with N. However, the PGPB isolates did not promote N accumulation and chlorophyll content similar to those of uninoculated plants supplied with N. The IPACC26 and IPACC30 isolates, both identified as Bacillus subtilis, resulted in better responses for plant growth and N accumulation than the other isolates.


2020 ◽  
Author(s):  
Qian Song ◽  
Xiaoshuang Song ◽  
Xun Deng ◽  
Jiayu Luo ◽  
Junkai Wang ◽  
...  

Abstract [Objective] Determine the ability of three plant growth promoting rhizobacteria (PGPR) strains (Pseudomonas Mandelli A36, Serratia plymuthica A13 and Pseudomonas koreensis A20) to promote plant growth, evaluate the effect of inoculation with PGPR strains on seedling biomass, root structure, nutrient index, and enzyme activity, and assess the effect of PGPR inoculation on soil nutrient index, enzyme activity, and the soil microecological environment.[Method] The ability of the three PGPR strains to secrete indole-3-acetic acid (IAA), dissolve inorganic phosphorus, and produce siderophore and hydrolase was determined by the medium color change method, pot experiment to determine the effects of three PGPR strains on plant biomass, physicochemical properties, soil physicochemical properties and microbial diversity. [Result] The three PGPR strains had the ability to secrete IAA, solubilize inorganic phosphorus, and produce siderophore, the results of the pot experiment showed that inoculation with PGPR strain had a significant effect on plant biomass, root index, nutrient index and enzyme activity, as well as soil nutrient index, enzyme activity and bacterial diversity. [Conclusion] This study provides basic data references for PGPR strains to improve the soil microecological environment and promote the growth and development of Pinus sylvestris var. Mongolica seedlings.


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