Exploring Potential Soil Bacteria for Sustainable Wheat (Triticum aestivum L.) Production

The application of plant growth-promoting rhizobacteria (PGPR) could allow growers to reduce the use of synthetic fertilizers and increase the sustainability of crop production. Wheat is the main staple food crop of Pakistan, and few studies have reported on the impact of PGPR on wheat crops. To determine if PGPR can maintain wheat productivity with reduced fertilizer applications, we isolated bacteria from the rhizosphere of wheat grown in sandy loam. We selected 10 strains based on in vitro assays for traits associated with PGPR: ACC deaminase activity, siderophore productivity, P-solubilization, and productivity of indole acetic acid (IAA). Furthermore, the strains were tested in three experiments (using a growth-chamber, pots with an experimental area of 0.05 m2, and a field). Strains that possessed the four traits associated with PGPR increased the shoot length, root length, and fresh and dry weight of plants in the growth chamber study. Similarly, under the pot trial, maximum crop traits were observed under the consortium + half dose, while under field conditions maximum crop parameters were detected in the case of consortium 1 and consortium 2 along with half the recommended dose of fertilizer. This confirms that this consortium could provide growers with a sustainable approach to reduce synthetic fertilizer usage in wheat production.

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Selection of phytotoxin producing rhizobacteria

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652011005000009 ◽

2011 ◽

Vol 83 (3) ◽

pp. 1091-1096 ◽

Cited By ~ 1

Author(s):

Daniel D.C. Carvalho ◽

Denilson F. Oliveira ◽

Vicente P. Campos ◽

Moacir Pasqual

Keyword(s):

Seed Germination ◽

Sucrose Solution ◽

Triticum Aestivum L ◽

In Vitro Assays ◽

Lettuce Seed ◽

Bacterial Strains ◽

Coleoptile Growth ◽

Liquid Phases ◽

Freeze Dried

In order to select phytotoxin producing rhizobacteria to control weed plants, twenty five bacterial strains previously isolated from the rhizospheres of various plants were grown in a liquid medium and, after cell removal by centrifugation, the liquid phases were freeze-dried and the products were extracted with ethyl acetate/methanol. The extracts were concentrated to dryness under vacuum and dissolved in water and sucrose solution to be submitted to in vitro assays of lettuce (Lactuca sativa L.) seed germination and wheat (Triticum aestivum L.) coleoptile growth. Although most samples affected coleoptile growth, only those from four strains reduced lettuce seed germination. Two strains of Bacillus cereus, one strain of B. pumilus and one of Stenotrophoonas altophilia were the most promising microorganisms for producing phytotoxin and, consequently, for the development of new weed control products.

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Relative cost to soil fertility of long-term crop production without fertilization

Canadian Journal of Plant Science ◽

10.4141/cjps96-071 ◽

1996 ◽

Vol 76 (3) ◽

pp. 401-406 ◽

Cited By ~ 7

Author(s):

C. A. Campbell ◽

F. Selles ◽

J. T. Harapiak ◽

G. P. Lafond

Keyword(s):

Soil Moisture ◽

Soil Fertility ◽

Green Manure ◽

Soil Degradation ◽

Crop Production ◽

Cropping Systems ◽

Triticum Aestivum L ◽

Growth Chamber ◽

Rotation Phase ◽

N Fertility

An earlier analysis of yield trends of stubble-wheat in six cropping systems, over 35 yr, in a thin Black Chernozemic soil at Indian Head, Saskatchewan, showed that fertilizer improved soil quality, while absence of fertilizer, combined with frequent fallowing, led to soil degradation. The inclusion of a legume green manure crop in the rotation failed to maintain soil fertility, apparently because legumes do not supply P. Because the fertility and stored moisture effects were confounded, we conducted a growth chamber experiment to quantify soil responses to N and P in these six cropping systems. Soil from the top 15-cm of the rotation phase that had just grown two successive wheat (Triticum aestivum L.) crops was used. Various factorial combinations of ammonium nitrate-N and triple superphosphate-P were applied at N/P2O5 rates up to 200/200 kg ha−1. Soil moisture was maintained in the available range. Regression analysis showed that the fallow-wheat-wheat (F-W-W) and continuous wheat (Cont W) systems that had not been fertilized in 35 yr, and which had moderate amounts of NaHCO3-P, only responded to N. In contrast, the green manure (GM)- and hay (H)- containing systems, which had also not been fertilized before had low levels of NaHCO3-P and responded to both N and P. In the field, the yields of wheat grown on stubble in 1991 rated: Cont W (N + P) > F-W-W (N + P) > F-W-W-H-H-H > Cont W > GM-W-W > F-W-W. However, in the growth chamber the rating was: Cont W (N + P) > F-W-W-H-H-H > GM-W-W > Cont W > F-W-W (N + P) > F-W-W. We suggest that the growth chamber results more accurately reflect the present fertility status of these soils, because fertility is no longer confounded with soil moisture. Grain yields in the growth chamber were directly proportional to the previously measured initial potential rate of N mineralization, indicating the value of the latter parameter as a useful index of soil N fertility. Key words: Nitrogen, phosphorus, soil degradation, legumes, fertilizers

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Ferric Iron Reduction by Bacteria Associated with the Roots of Freshwater and Marine Macrophytes

Applied and Environmental Microbiology ◽

10.1128/aem.65.10.4393-4398.1999 ◽

1999 ◽

Vol 65 (10) ◽

pp. 4393-4398 ◽

Cited By ~ 71

Author(s):

G. M. King ◽

Meredith A. Garey

Keyword(s):

Iron Reduction ◽

Ferric Iron ◽

Sodium Molybdate ◽

Dry Weight ◽

Root Activity ◽

In Vitro Assays ◽

Freshwater Macrophytes ◽

Marine Macrophytes ◽

Marine Isolate

ABSTRACT In vitro assays of washed, excised roots revealed maximum potential ferric iron reduction rates of >100 μmol g (dry weight)−1 day−1 for three freshwater macrophytes and rates between 15 and 83 μmol (dry weight)−1 day−1 for two marine species. The rates varied with root morphology but not consistently (fine root activity exceeded smooth root activity in some but not all cases). Sodium molybdate added at final concentrations of 0.2 to 20 mM did not inhibit iron reduction by roots of marine macrophytes (Spartina alterniflora and Zostera marina). Roots of a freshwater macrophyte, Sparganium eurycarpum, that were incubated with an analog of humic acid precursors, anthroquinone disulfate (AQDS), reduced freshly precipitated iron oxyhydroxide contained in dialysis bags that excluded solutes with molecular weights of >1,000; no reduction occurred in the absence of AQDS. Bacterial enrichment cultures and isolates from freshwater and marine roots used a variety of carbon and energy sources (e.g., acetate, ethanol, succinate, toluene, and yeast extract) and ferric oxyhydroxide, ferric citrate, uranate, and AQDS as terminal electron acceptors. The temperature optima for a freshwater isolate and a marine isolate were equivalent (approximately 32°C). However, iron reduction by the freshwater isolate decreased with increasing salinity, while reduction by the marine isolate displayed a relatively broad optimum salinity between 20 and 35 ppt. Our results suggest that by participating in an active iron cycle and perhaps by reducing humic acids, iron reducers in the rhizoplane of aquatic macrophytes limit organic availability to other heterotrophs (including methanogens) in the rhizosphere and bulk sediments.

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Soaps and Detergents: Alternatives to Animal Eye Irritation Tests

Journal of the American College of Toxicology ◽

10.3109/10915819609008705 ◽

1996 ◽

Vol 15 (1) ◽

pp. 1-44 ◽

Cited By ~ 17

Author(s):

Mildred S. Christian ◽

Robert M. Diener

Keyword(s):

False Negative ◽

Screening Tools ◽

Current Status ◽

In Vitro Assays ◽

Computer Search ◽

Eye Irritation ◽

Vitro Assay ◽

Predictive Values ◽

The Impact

An extensive computer search was conducted, and a comprehensive overview of the current status of alternatives to animal eye irritation tests was obtained. A search of Medline and Toxline databases (1988 to present) was supplemented with references from sources regarding in vitro eye irritation. Particular attention was paid to soap and detergent products and related ingredients. Eighty-five references are included in the review; the in vitro assays are categorized, and their predictive values for assessing acute ocular irritation are evaluated and compared with the Draize rabbit eye irritation assay and with each other. The present review shows that the increased activity of scientists from academia, industry, and regulatory agencies has resulted in substantial progress in developing alternative in vitro procedures and that a number of large, interlaboratory evaluations and international workshops have assisted in the selection process. However, none of these methodologies has obtained acceptance for regulatory classification purposes. Conclusions drawn from this review include that (a) no single in vitro assay is considered capable of replacing the Draize eye irritation test; (b) the chorioallantoic membrane vascular assay (CAMVA) or the hen egg test-chorio-allantoic membrane test (HET-CAM), the chicken or bovine enucleated eye test, the neutral red and plasminogen activation assays for cytotoxicity, and the silicon microphysiometer appear to have the greatest potential as screening tools for eye irritation; and (c) choosing a specific assay or series of assays will depend on the type of agent tested and the impact of false-negative or false-positive results. New assays will continue to be developed and should be included in future evaluations, when sufficient data are available.

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EFFECT OF LIGHT, CO2, AND SUCROSE CONCENTRATIONS ON THE IN VITRO GROWTH OF WHITE POTATO (SOLANUM TUBEROSUM L.)

HortScience ◽

10.21273/hortsci.27.6.696f ◽

1992 ◽

Vol 27 (6) ◽

pp. 696f-696

Author(s):

N.C. Yorio ◽

R.M. Wheeler ◽

R.C. Weigel

Keyword(s):

Solanum Tuberosum ◽

Solanum Tuberosum L ◽

Dry Weight ◽

Growth Chamber ◽

Photon Flux ◽

Photosynthetic Photon Flux ◽

White Potato ◽

High Sucrose ◽

Effect Of Light

Growth measurements of potato (Solanum tuberosum L.) cvs. Norland (NL), Denali (DN), and Kennebec (KN) were taken from 21-day-old plantlets grown in vitro. Studies were conducted in a growth chamber, with nodal explants grown in culture tubes with loose-fitted Magenta 2-way caps containing Murashige and Skoog salts with either 0, 1, 2 or 3% sucrose. The cultures received either 100 or 300 μmol m-2 s-1 photosynthetic photon flux (PPF), and the growth chamber was maintained at either 400 or 4000 μmol mol-1 CO2. All cvs. showed significant increases in growth on 0% sucrose media at 4000 μmol mol-1 CO2, indicating an autotrophic response. At 400 μmol mol-1 CO2, all cvs. showed an increase in total plantlet dry weight (DW) with increasing sucrose under both PPF levels. Within any sucrose treatment, the highest total DW for all cvs. resulted from 300 μmol m-2 s-1 PPF and 4000 μmol mol-1 CO2. At 4000 μmol mol-1 CO2, shoot DW declined with sucrose above 2% for DN and sucrose above 1% for NL at both PPF levels, suggesting that high sucrose levels may hinder growth when CO2 enrichment is used.

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Efecto de bacterias promotoras de crecimiento vegetal (PGPR) asociadas a Pennisetum clandestinum en el altiplano cundiboyacense

Ciencia y Tecnología Agropecuaria ◽

10.21930/rcta.vol13_num2_art:254 ◽

2013 ◽

Vol 13 (2) ◽

pp. 189 ◽

Cited By ~ 4

Author(s):

Paola Jimena Criollo ◽

Melissa Obando ◽

Leonardo Sánchez M. ◽

Ruth Bonilla

Keyword(s):

Dry Weight ◽

Plant Growth Promoting Rhizobacteria ◽

Pennisetum Clandestinum ◽

Root Dry Weight ◽

Indole Compounds ◽

Plant Growth Promoting ◽

Biological Nitrogen ◽

Absolute Control

Pennisetum clandestinum (kikuyo) es una pastura común en los sistemas silvopastoriles del altiplano cundiboyacense, con altas propiedades nutritivas. Por tanto estudios que permitan mejorar el proceso de producción en términos económicos y ambientales reviste gran importancia. En este estudio se evaluó el papel de la inoculación con bacterias promotoras de crecimiento vegetal (PGPR) sobre el crecimiento de pasto kikuyo. Las cepas 4K y 5B fueron identificadas mediante amplificación y análisis del 16S rADN, como Stenotrophomona ssp. y Pseudomona ssp., respectivamente, caracterizadas por su eficiencia in vitro en la fijación biológica de nitrógeno, producción de compuestos indólicos y solubilización de fosfatos. Se evaluaron las cepas en condiciones de invernadero en tres tiempos de crecimiento de la planta (70, 100 y 130 días). Se evidenció que la cepa 4K incrementó el peso seco radicular de la planta en 50% a los 70 y 100 días, mientras que la cepa 5B mostró un comportamiento similar en el peso seco aéreo y radicular con aumentos de hasta el 50% a los 130 d. El efecto más importante se presentó después de 100 d donde los tratamientos TQ, TB1 y TB2, superaron en más del 80% al testigo absoluto en el peso fresco de la parte aérea. Estos resultados demostraron que la inoculación de PGPR representa una alternativa biotecnológica para promover el crecimiento de P. clandestinum, con efectos relevantes en producción de biomasa 100 días después de la siembra (dds). Effect of plant growth-promoting rhizobacteria (PGPR) associated to Pennisetum clandestinum in the altiplano cundiboyacense Pennisetum clandestinum (kikuyo) is a common pasture in the altiplano cundiboyacense silvopastoral systems, which possesses high nutritional value. Therefore, studies to improve the production process in both economic and environmental terms are very important. The role of inoculation with plant growthpromoting bacteria was evaluated on the growth of kikuyu grass. The 4K and 5B strains were identified, through amplification and analysis of their 16S rDNA, as members of the Stenotrophomonas and Pseudomonas genera, respectively. They were characterized in vitro for their efficiency of biological nitrogen fixation, production of indole compounds, and phosphate solubilization. Four treatments were evaluated under greenhouse conditions. Furthermore, the biomass was evaluated at different stages of the plant (70, 100 and 130 days). The 4K strain demonstrated a root dry weight that increased by 50% at 70 and 100 days and the 5B strain showed a statistically significant behavior for plant and root dry weight with an increase of 50% at 130 days. The most important effect was presented after 100 d where treatments, TQ, TB1 and TB2, exceeded more 80% to absolute control in the fresh weight of the air. These results showed that inoculation with PGPR represents a biotechnological alternative to promote growth of P. clandestinum, as we observed relevant effects on biomass production 100 days after planting.

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Evaluation of different growth hormones mediated callus induction and regeneration as well as the effect of colchicines, ethyl methanesulfonate (EMS) and gamma radiation on some traits of Impatiens walleriana

Genetika ◽

10.2298/gensr2101379s ◽

2021 ◽

Vol 53 (1) ◽

pp. 379-391

Author(s):

Sedigheh Sharafi ◽

Pejman Azadi ◽

Maryam Jafarkhani Kermani ◽

Vahid Abdossi ◽

Ali Eskandri

Keyword(s):

Dry Weight ◽

Control Treatment ◽

Lower Survival Rate ◽

Randomized Design ◽

Effective System ◽

Number Of Leaves ◽

Impatiens Walleriana ◽

The Impact ◽

Disease Free

Impatiens is an ornamental member of family Balsaminaceae. This plant mostly propagated by vegetative technique, which generally time wasting process. It is often multiplicities via seed but is barricaded by F1 seed sterility. In vitro culture of Impatiens walleriana has much significant function in fast proliferation with useful features and elicitation of healthful and disease-free plants. This experiment was conducted to investigate the impact of medium and different hormones on in vitro propagation of Impatiens walleriana by using a completely randomized design. MS medium was prepared along with various concentrations of BAP, TDZ and ZEA. Callus was induced and grew well in media supplemented with 0.5 mg/l NAA + 1 mg/l BAP. In order to indirect propagation, explants were cultured in same media containing BAP, ZEA and TDZ in combination with NAA. These treatments have ability to organogenesis. The results revealed that the control treatment had the lowest effect on traits including shoot percentage, number of shoots, number of leaves, shoot length, fresh and dry weight, and it lead to maximum proliferations in medium supplemented with 0.5 mg/l NAA + 1 mg/l BAP. The highest root length and rooting percentage was observed in 0.5 mg/l IBA + 0.5 mg/l BAP. In addition, the effect of mutation agents was studied. Aseptic samples were treated with ?- irradiation, Ethyl Methane Sulfonate and colchicines at growth chamber. Treatments with 30 and 60 grey respectively had the lower survival rate, growth rate and polyploidy while colchicines with 0.1 and 0.2 had the highest rats. Regarding to these, the present technique illustrate an effective system for in vitro reproduction of Impatiens walleriana by hypocotyls cultures. In addition, colchicines proved to be effective in induction of polyploidy in this plantlet.

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Effects of Potassium Availability on Growth and Development of Barley Cultivars

Agronomy ◽

10.3390/agronomy11112269 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2269

Author(s):

Widad Al Azzawi ◽

Muhammad Bilal Gill ◽

Foad Fatehi ◽

Meixue Zhou ◽

Tina Acuña ◽

...

Keyword(s):

Crop Production ◽

Dry Weight ◽

Major Effect ◽

Grain Weight ◽

Grain Number ◽

Barley Cultivars ◽

Shoot Dry Weight ◽

Spike Number ◽

Potassium Supply ◽

The Impact

Potassium deficiency is one of the major issues affecting crop production around the globe. Giving the high cost of potassium fertilizers and environmental concerns related to inappropriate fertilization practices, developing more potassium use efficient (KUE) varieties is critical for sustainable food production in agricultural systems. In this study, we analysed the impact of potassium availability on agronomical attributes of thirty barley genotypes grown at four different levels of potassium (0.002 mM, 0.02 mM, 2 mM, 20 mM) under glasshouse conditions. The results showed that the availability of potassium in the soil had a major effect on yield components i.e., spike number, grain number and grain weight. Furthermore, grain weight showed a strong correlation with grain number and spike number at all levels of potassium supply. Although an increase in potassium supply led to an increase in plant height in all genotypes, the correlation with grain weight was very weak at all levels. Potassium supplementation caused an increase in shoot dry weight, which also showed a weak correlation with grain weight at the 0.002 mM potassium supply level. The genotypes Gebeina, Skiff, YF374, Flagship and YF374 were highly efficient in performing at suboptimal K supply levels and, thus, can be recommended to be grown in K-impoverished soils. We also suggest that grain and spike numbers could be used as proxies for KUE studies, to construct DH lines and identify QTL to improve low potassium tolerance and KUE in barley.

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Evaluation of diverse range microbes for their plant growth promoting abilities and their pesticide compatibility

Environment Conservation Journal ◽

10.36953/ecj.2021.22306 ◽

2021 ◽

pp. 47-58

Author(s):

Tulja Sanam ◽

S. Triveni ◽

J. Satyanaryana ◽

Sridhar Goud Nerella ◽

K. Damodara Chari ◽

...

Keyword(s):

Plant Growth ◽

Plant Growth Promoting Rhizobacteria ◽

Atomic Absorption Spectrophotometry ◽

In Vitro Assays ◽

Bacterial Isolates ◽

Diverse Range ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Bacillus Isolate

Plant growth-promoting rhizobacteria (PGPR) contribute to an increase in crop yield through an environmentally friendly method, therefore eight rhizospheric bacteria, two of each genera Bacillus, Pseudomonas, Azotobacter and Azospirillum were examined for their efficacy to solubilize mineral nutrients using atomic absorption spectrophotometry and a flame photometer. Their potency to produce phytohormones, synthesis biocontrol components and their compatibility with pesticides using in vitro assays was studied. All of the chosen bacterial isolates proved positive for the above-mentioned Plant Growth Promoting traits. Among the eight bacterial isolates Pseudomonas isolate P69 showed the highest phosphorous solubilization efficiency of 190.91 % and another isolate P48 produced a maximum of 27.63µg mL-1 of gibberellic acid, Bacillus isolate B120 could solubilize maximum amount of ZnO and ZnCO3 accounting for 21.3ppm and 25.9ppm, respectively, not merely in terms of solubilization when compared to the other isolates, B120 produced the highest levels of HCN (77.33 ppm TCC) and siderophores (48.87psu). On day 9 after inoculation, Azotobacter isolate AZB17 performed effectively in potassium solubilization of 6.25g mL-1 with a pH drop to 3.83. The Azospirillum isolate ASP25 outperformed all other isolates in terms of IAA production (22.64g mL-1) and Bacillus isolate B365 was found to be more compatible with eight different pesticides used in the field at varying concentrations. All of these factors point to the possibility of using these bacterial isolates B120, P48, P69, AZB17, and ASP25 as biofertilizers in sustainable agriculture.

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Microbiological Insights into the Stress-Alleviating Property of an Endophytic Bacillus altitudinis WR10 in Wheat under Low-Phosphorus and High-Salinity Stresses

Microorganisms ◽

10.3390/microorganisms7110508 ◽

2019 ◽

Vol 7 (11) ◽

pp. 508 ◽

Cited By ~ 1

Author(s):

Yue ◽

Shen ◽

Chen ◽

Liang ◽

Chu ◽

...

Keyword(s):

Abiotic Stresses ◽

Germination Rate ◽

Acc Deaminase ◽

Dry Weight ◽

Triticum Aestivum L ◽

Culture Conditions ◽

Wheat Seedlings ◽

Bacillus Altitudinis ◽

Phosphorus Stress ◽

Low Phosphorus

An indole–3–acetic acid producing Bacillus altitudinis WR10 was previously isolated from the root of wheat (Triticum aestivum L.). In this study, the strain WR10 was used for relieving abiotic stresses in wheat under low phosphorus and high saline in hydroponic co-culture models. Significantly, strain WR10 improved wheat seed relative germination rate under salinity stress (200/400 mM NaCl) and the root dry weight in wheat seedlings under phosphorus stress (10 μM KH2PO3) when insoluble phosphates are available. To provide insights into its abiotic stress-alleviating properties, the strain was characterized further. WR10 grows well under different culture conditions. Particularly, WR10 resists salt (12% NaCl) and hydrolyzes both inorganic and organic insoluble phosphates. WR10 uses many plant-derived substrates as sole carbon and energy sources. It produces catalase, amylase, phosphatase, phytase, reductase, and 1–aminocyclopropane–1–carboxylate (ACC) deaminase. In addition, WR10 possesses long peritrichous flagella, and its biofilm formation, as well as phytase production, is induced by abiotic stresses. Overall, the salinity-alleviating property of WR10 in wheat can be attributed to its inherent tolerance to NaCl, formation of biofilm, and production of enzymes, like catalase, amylase, and ACC deaminase. Meanwhile, B. altitudinis WR10 reduces low-phosphorus stress in wheat by production of phosphatases and phytases in the presence of insoluble phosphates.

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