Spruce growth response specificity after treatment with plant growth-promoting Pseudomonads

1999 ◽  
Vol 77 (1) ◽  
pp. 22-31 ◽  
Author(s):  
Masahiro Shishido ◽  
Christopher P Chanway

Naturally regenerating hybrid spruce seedlings (Picea glauca (Moench) Voss beta Picea engelmannii Parry) were collected from sites near Mackenzie, Salmon Arm, and Williams Lake, British Columbia, Canada. Bacteria were isolated from roots and screened in greenhouse trials for their ability to enhance spruce growth. Three strains belonging to the genus Pseudomonas were selected for study based on their disparate geographic origins and their capacity to consistently stimulate spruce seedling growth in screening trials. Factorial experiments were performed in the greenhouse to evaluate the effectiveness of these Pseudomonas strains with different spruce ecotypes. Factors tested were spruce seed sources, Pseudomonas isolates, and forest floor soils originating from different sites. Three levels of each factor were studied: one spruce seedlot, one Pseudomonas isolate, and one forest floor type each originated from a site at Mackenzie, Salmon Arm, and Williams Lake, British Columbia. Fourteen weeks after treatments were established, spruce biomass accumulation was greatest when spruce ecotypes were inoculated with bacteria originating from the same geographical area as spruce seed. However, Pseudomonas strains originating from sites other than the seed collection area also stimulated seedling growth significantly, rendering the difference in growth promotion between bacterial treatments small and insignificant. In addition, spruce growth promotion was not enhanced when seed was treated with combinations of Pseudomonas strains and forest floor soils originating from the same forest ecosystem. We conclude that specificity between spruce ecotypes and plant growth-promoting rhizobacteria strains can be detected under carefully controlled conditions, thereby supporting the hypothesis that growth-promoting bacteria may adapt to their plant hosts. However, the growth advantage accruing to seedlings treated with bacteria originating from the same ecosystem is small and suggests that it is not necessary to match Pseudomonas strains with spruce ecotypes and soil types for effective seedling growth promotion.Key words: Pseudomonas, spruce, specificity, growth promotion.

2000 ◽  
Vol 30 (6) ◽  
pp. 845-854 ◽  
Author(s):  
Masahiro Shishido ◽  
Christopher P Chanway

Seeds of two hybrid spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.) ecotypes were inoculated with one of six plant growth-promoting rhizobacteria (PGPR) strains previously shown to be able to stimulate spruce growth in controlled environments. The resulting seedlings were grown in the greenhouse for 17 weeks before outplanting at four reforestation sites. Inoculation with five of the six strains caused significant seedling growth promotion in the greenhouse, which necessitated analysis of relative growth rates (RGR) to evaluate seedling performance in the field. Four months after outplanting, most strains enhanced spruce shoot or root RGRs in the field, but seedling growth responses were strain specific. For example, Pseudomonas strain Ss2-RN significantly increased both shoot and root RGRs by 10-234% at all sites, but increases of 28-70% were most common. In contrast, Bacillus strain S20-R was ineffective at all outplanting sites. In addition, seedlings inoculated with four of the six strains had significantly less shoot injury than control seedlings at all sites. Evaluation of root colonization by PGPR indicated that bacterial population declines were not related to spruce growth response variability in the field. Our results indicate that once plant growth promotion is induced in the greenhouse, seedling RGR can increase by more than 100% during the first growing season in the field. However RGR increases of 21-47% were more common and may be more representative of the magnitude of biomass increases that can result from PGPR inoculation.


2014 ◽  
Vol 65 (1) ◽  
pp. 71-77
Author(s):  
Ghazala Nasim ◽  
Sobia Mushtaq ◽  
Irum Mukhtar ◽  
Ibatsam Khokhar

AbstractPenicilliumspp. are well known to produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. In this study, effects of culture filtrate of differentPenicilliumspp. were tested on tomato seeds. On the whole, presoaking of seeds in filtrates of the ninePenicilliumisolates tested, significantly increased seed germination when compared with the control seeds. Cultural extracts ofP. expensumandP. billiwere highly effective in growth promotion up to 90%. It was also observed thatP. implicatumandP. oxlalicamsignificantly enhanced the root growth in tomato seedling as compare to other species. In case of shoot length,P. verrucosum(3.38),P. granulatum(2.81) andP. implicatum(2.62) were effective. HoweverP. implicatumwas quite promising to increase shoot and root length in tomato seedlings. Where asP. simplicissimiumandP. citrinumwere leas effective on seedling growth. The plant growth promoting ability ofPenicilliumstrains may help in growth permotion in other plants and crops.Penicilliumspp. are already known for producing mycotoxin and enzymes. Plant growth promoting ability ofPenicilliumspp will open new aspects of research and investigations. The role ofPenicil-liumspp. in tomato plant growth requires further exploration.


2021 ◽  
Vol 11 (5) ◽  
pp. 2233
Author(s):  
Maria J. Ferreira ◽  
Angela Cunha ◽  
Sandro Figueiredo ◽  
Pedro Faustino ◽  
Carla Patinha ◽  
...  

Root−associated microbial communities play important roles in the process of adaptation of plant hosts to environment stressors, and in this perspective, the microbiome of halophytes represents a valuable model for understanding the contribution of microorganisms to plant tolerance to salt. Although considered as the most promising halophyte candidate to crop cultivation, Salicornia ramosissima is one of the least-studied species in terms of microbiome composition and the effect of sediment properties on the diversity of plant-growth promoting bacteria associated with the roots. In this work, we aimed at isolating and characterizing halotolerant bacteria associated with the rhizosphere and root tissues of S. ramosissima, envisaging their application in saline agriculture. Endophytic and rhizosphere bacteria were isolated from wild and crop cultivated plants, growing in different estuarine conditions. Isolates were identified based on 16S rRNA sequences and screened for plant-growth promotion traits. The subsets of isolates from different sampling sites were very different in terms of composition but consistent in terms of the plant-growth promoting traits represented. Bacillus was the most represented genus and expressed the wider range of extracellular enzymatic activities. Halotolerant strains of Salinicola, Pseudomonas, Oceanobacillus, Halomonas, Providencia, Bacillus, Psychrobacter and Brevibacterium also exhibited several plant-growth promotion traits (e.g., 3-indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophores, phosphate solubilization). Considering the taxonomic diversity and the plant-growth promotion potential of the isolates, the collection represents a valuable resource that can be used to optimize the crop cultivation of Salicornia under different environmental conditions and for the attenuation of salt stress in non-halophytes, considering the global threat of arable soil salinization.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.


2021 ◽  
Vol 16 (8) ◽  
pp. 75-80
Author(s):  
Pitchaiah Pelapudi ◽  
Sasikala Ch ◽  
Swarnabala Ganti

In the present rapid growing world, need for a sustainable agricultural practice which helps in meeting the adequate food demand is much needed. In this context, plant growth promoting bacteria were brought into the spot light by the researchers. Though the plant growth promoting bacteria have several beneficial applications, due to some of the disadvantages in the field conditions, they lagged behind. In the current research work, native PGPR were isolated from the rhizosphere soil samples of maize with an aim to isolate the nitrogen fixing, phosphate solubilising and potash solubilising bacteria. Out of the several isolates, potent PGPR isolates viz., Paenibacillus durus PCPB067, Bacillus megaterium PCBMG041 and Paenibacillus glucanolyticus PCPG051 were isolated and identified by using the 16 S rRNA gene sequencing studies. Genomic DNA sequences obtained were deposited in the NCBI Genbank and accession numbers were assigned as MW793452, MW793456 and MW843633. In order to check the efficacy of the PGPR isolates, pot trials were conducted by taking maize as the host plant. Several parameters viz. shoot length, shoot weight, root length, root weight and weight of the seeds were tested in which PGP treatment showed good results (shoot length - 187±3.5 cm, shoot weight - 31±4 g, root length - 32±3.6 cm, root weight - 17±2 g, yield- 103.3±6.1 g) when compared to the chemical fertilizer treatment (shoot length - 177±3.5 cm, shoot weight - 25±3.6 g, root length - 24±3.5 cm, root weight - 14.6±1.52 g, yield- 85.6±7.6 g). Based on the results, it can be stated that these native PGPR isolates can be effectively used in the plant growth promotion of maize.


2017 ◽  
Vol 5 (5) ◽  
Author(s):  
Vanessa Nessner Kavamura ◽  
Suikinai Nobre Santos ◽  
Rodrigo Gouvêa Taketani ◽  
Rafael Leandro Figueiredo Vasconcellos ◽  
Itamar Soares Melo

ABSTRACT The strain of Bacillus sp. CMAA 1363 was isolated from the Brazilian Caatinga biome and showed plant growth-promoting traits and ability to promote maize growth under drought stress. Sequencing revealed genes involved in stress response and plant growth promotion. These genomic features might aid in the protection of plants against the negative effects imposed by drought.


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