Coinoculation of chickpea with Rhizobium isolates from roots and nodules and phytohormone-producing Enterobacter strains

2007 ◽  
Vol 47 (8) ◽  
pp. 1008 ◽  
Author(s):  
Babur Saeed Mirza ◽  
M. Sajjad Mirza ◽  
Asghari Bano ◽  
Kauser A. Malik

The aim of the present study was to isolate plant-beneficial bacteria (both Rhizobium and plant growth promoting rhizobacteria) from roots and nodules of chickpea (Cicer arietinum L.) and to study the effect of coinoculations on growth of two cultivars of chickpea. Four Rhizobium strains were obtained from roots and four from the nodules of field-grown chickpea cv. Parbat and identified on the basis of morphological characteristics, and biochemical and infectivity tests on the host seedlings. Only one type of nitrogen and carbon source utilisation pattern and DNA banding pattern of random amplified polymorphic DNA was observed in all isolates (Rn1, Rn2, Rn3, Rn4) from nodules, while two types of such patterns were detected among the isolates from roots. The isolate Rr1 from roots also exhibited a pattern identical to those of the isolates from nodules, whereas the remaining three isolates (Rr2, Rr3 and Rr4) from roots showed a different pattern. Two strains of plant growth-promoting rhizobacteria belonging to genus Enterobacter were also isolated from chickpea roots. All the Rhizobium strains and Enterobacter strains produced the plant growth hormones indole acetic acid and gibberellic acid in the growth medium. Effects of the bacterial isolates as single- or double-strain inocula were studied on two chickpea cultivars (NIFA 88 and Parbat) grown in sterilised soil. In cultivar NIFA 88, coinoculation of Rhizobium strain Rn1 with Enterobacter strain B resulted in maximum increase in plant biomass and nodulation, as compared with the control treatment (non-inoculated as well as inoculated with Rhizobium strain Rn1 only), whereas the combination of Rhizobium Rn1 with Enterobacter A was more efficient in growth promotion of chickpea cv. Parbat. In non-sterilised soil, the same combinations of the Rhizobium strain Rn1 with Enterobacter strains A and B were found to be the most effective inoculants for cvv. Parbat and NIFA 88, respectively. However, some negative effects on plant growth were also noted in cv. Parbat coinoculated with Rhizobium strain Rr2 and Enterobacter strain B.

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 894
Author(s):  
Emad M. Hafez ◽  
Hany S. Osman ◽  
Usama A. Abd El-Razek ◽  
Mohssen Elbagory ◽  
Alaa El-Dein Omara ◽  
...  

The continuity of traditional planting systems in the last few decades has encountered its most significant challenge in the harsh changes in the global climate, leading to frustration in the plant growth and productivity, especially in the arid and semi-arid regions cultivated with moderate or sensitive crops to abiotic stresses. Faba bean, like most legume crops, is considered a moderately sensitive crop to saline soil and/or saline water. In this connection, a field experiment was conducted during the successive winter seasons 2018/2019 and 2019/2020 in a salt-affected soil to explore the combined effects of plant growth-promoting rhizobacteria (PGPR) and potassium (K) silicate on maintaining the soil quality, performance, and productivity of faba bean plants irrigated with either fresh water or saline water. Our findings indicated that the coupled use of PGPR and K silicate under the saline water irrigation treatment had the capability to reduce the levels of exchangeable sodium percentage (ESP) in the soil and to promote the activity of some soil enzymes (urease and dehydrogenase), which recorded nearly non-significant differences compared with fresh water (control) treatment, leading to reinstating the soil quality. Consequently, under salinity stress, the combined application motivated the faba bean vegetative growth, e.g., root length and nodulation, which reinstated the K+/Na+ ions homeostasis, leading to the lessening or equalizing of the activity level of enzymatic antioxidants (CAT, POD, and SOD) compared with the controls of both saline water and fresh water treatments, respectively. Although the irrigation with saline water significantly increased the osmolytes concentration (free amino acids and proline) in faba bean plants compared with fresh water treatment, application of PGPR or K-silicate notably reduced the osmolyte levels below the control treatment, either under stress or non-stress conditions. On the contrary, the concentrations of soluble assimilates (total soluble proteins and total soluble sugars) recorded pronounced increases under tested treatments, which enriched the plant growth, the nutrients (N, P, and K) uptake and translocation to the sink organs, which lastly improved the yield attributes (number of pods plant−1, number of seeds pod−1, 100-seed weight). It was concluded that the combined application of PGPR and K-silicate is considered a profitable strategy that is able to alleviate the harmful impact of salt stress alongside increasing plant growth and productivity.


2018 ◽  
Vol 109 (4) ◽  
pp. 479-489 ◽  
Author(s):  
R. Sattari Nasab ◽  
M. Pahlavan Yali ◽  
M. Bozorg-Amirkalaee

AbstractThe cabbage aphid, Brevicoryne brassicae L. (Hem: Aphididae), is an important pest of canola that can considerably limit profitable crop production either through direct feeding or via transmission of plant pathogenic viruses. One of the most effective approaches of pest control is the use of biostimulants. In this study, the effects of humic acid, plant growth-promoting rhizobacteria (PGPR), and integrated application of both compounds were investigated on life table parameters of B. brassicae, and the tolerance of canola to this pest. B. brassicae reared on plants treated with these compounds had the lower longevity, fecundity, and reproductive period compared with control treatment. The intrinsic rate of natural increase (r) and finite rate of increase (λ) were lowest on PGPR treatment (0.181 ± 0.004 day−1 and 1.198 ± 0.004 day−1, respectively) and highest on control (0.202 ± 0.005 day−1 and 1.224 ± 0.006 day−1, respectively). The net reproductive rate (R0) under treatments of humic acid, PGPR and humic acid + PGPR was lower than control. There was no significant difference in generation time (T) of B. brassicae among the tested treatments. In the tolerance test, plants treated with PGPR alone or in integrated with humic acid had the highest tolerance against B. brassicae. The highest values of total phenol, flavonoids, and glucosinolates were observed in treatments of PGPR and humic acid + PGPR. Basing on the antibiosis and tolerance analyses in this study, we concluded that canola plants treated with PGPR are more resistant to B. brassicae. These findings could be useful for integrated pest management of B. brassicae in canola fields.


1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes

Early seedling root growth of the nonlegumes canola (Brassica campestris cv. Tobin, Brassica napus cv. Westar) and lettuce (Lactuca saliva cv. Grand Rapids) was significantly promoted by inoculation of seeds with certain strains of Rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. The growfh-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. Auxotrophic Rhizobium mutants requiring tryptophan or adenosine (precursors for indole-3-acetic acid and cytokinin synthesis, respectively) did not promote growth to the extent of the parent strain. The findings of this study demonstrate a new facet of the Rhizobium–plant relationship and that Rhizobium leguminosarum can be considered a plant growth-promoting rhizobacterium (PGPR).Key words: Rhizobium, plant growth-promoting rhizobacteria, PGPR, indole-3-acetic acid, cytokinin, roots, auxotrophic mutants.


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.


Author(s):  
Di Fan ◽  
Donald L. Smith

There are pressing needs to reduce the use of agrochemicals, and PGPR are receiving increasing interest in plant growth promotion and disease protection. This study follows up our previous report that the four newly isolated rhizobacteria promote the growth of Arabidopsis thaliana .


2021 ◽  
Vol 21 (No 1) ◽  
Author(s):  
Aghajan bahadori ◽  
Mohmmad Hossein GHarineh ◽  
Abdolmahdi Bakhshandeh ◽  
Naeimeh Enayatizamir ◽  
Alireza Shafeinia

This study was performed in order to investigate the effect of Plant growth-promoting rhizobacteria in reducing nitrogen and phosphorus Fertilizers Application in Sugarcane. The field experiment of this study was in the form of Split–block design with subplots in stips with four replications and three factors, including bacterial factor at four levels (control, Enterobacter cloaca, Pseudomonas putida and a combination of two types of bacteria), nitrogen factor at three levels (50, 75 and 100% recommended nitrogen for sugarcane (and phosphorus factor at three levels (50, 75 and 100% recommended phosphorus for sugarcane), was carried out in 2016-2017crop year in DC7-10 research farm of Dehkhoda sugarcane agro-industryin Ahvaz, in the southwest of Iran, on CP73-21 sugarcane variety. According to the analysis of variance tables, simple and interaction effects of the tested treatments, in the case of quantitative traits, including stalk yield, height, diameter, stalk density, percentage of nitrogen and phosphorus of leaves, chlorophyll content, LAI and HI in sugarcane were significant at the level of 1% probability. Comparison of means showed that the application of simultaneous application of growth-promoting bacteria along with the application of 75% recommended nitrogen and phosphorus for sugarcane, compared with the control treatment (application of 100% recommended nitrogen and phosphorus for sugarcane, without the use of bacteria), Was able to succeed in these traits 96.9%, 98.1%, 95.7%, 96.3%, 100.2% ,101.9%, 91.2% and 94.8%, respectively and Provide 21/9, 23/1, 20/7, 21/3, 25, 25, 16.2 and 19.8% of the nutrients of nitrogen and phosphorus for sugarcane, respectively, and is saved the same amount of nitrogen and phosphorus consumption for sugarcane. Also, regarding the sugarcane yield, the simultaneous application treatment of the tested bacteria along with the application of 100% recommended phosphorus and nitrogen for sugarcane, Compared to the control treatment


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