Performance and Establishment of a Commercial Mycorrhizal Inoculant in Viticulture

(1) Background: Arbuscular mycorrhizal (AM) fungi are symbiotic organisms that help plants acquire nutrients from the soil in exchange for photosynthetic carbon. Commercial AM fungal inoculants are widely available and are used extensively in agriculture including wine grape production. However, positive growth responses from inoculants are more consistent in the greenhouse compared to the field. (2) Methods: We grew three grapevine rootstocks with and without an AM fungal inoculant in the greenhouse for one year, then they were transplanted to the field for two years. To quantify the establishment of the inoculant, we analyzed root samples with a digital PCR assay. (3) Results: We show that AM fungal inoculation increased biomass production only in the greenhouse. After two growing seasons in the field, the commercial inoculant colonized roots but did not increase biomass production compared to uninoculated rootstocks. (4) Conclusions: This study highlights that AM fungal inoculants do not always promote growth of grapevines in the field. Future research should focus on inoculant strains designed for viticulture applications and take rootstock into consideration to maximize their efficacy.

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Commercial arbuscular mycorrhizal fungal inoculant failed to establish in a vineyard despite priority advantage

PeerJ ◽

10.7717/peerj.11119 ◽

2021 ◽

Vol 9 ◽

pp. e11119

Author(s):

Corrina Thomsen ◽

Laura Loverock ◽

Vasilis Kokkoris ◽

Taylor Holland ◽

Patricia A. Bowen ◽

...

Keyword(s):

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Digital Pcr ◽

Priority Effects ◽

Plant Performance ◽

Agricultural System ◽

Available Phosphorus ◽

Fungal Abundance ◽

Before And After ◽

Commercial Inoculant

Background Arbuscular mycorrhizal (AM) fungi associate with most plants and can increase nutrient uptake. As a result, commercial inoculants called “biofertilizers” containing AM fungi have been developed and marketed to increase plant performance. However, successful establishment of these inoculants remains a challenge, and may be negatively impacted by competition with fungi already present (priority effects). Perennial agriculture may be more amenable if inoculants can be successfully established on crops prior to field planting. Methods Here, we inoculate grapevine (Vitis vinifera) with a commercial inoculant in three treatments designed to manipulate the strength and direction of priority effects and quantified the abundance of the fungal strain before and after introduction using droplet digital PCR (ddPCR). Results We found that the introduced strain did not establish in any treatment, even with priority advantage, and inoculated vines did not differ in performance from non-inoculated vines. Fungal abundance was not greater than in pre-inoculation soil samples during any of the five years sampled and may have been impaired by high available phosphorus levels in the soil. This study highlights the need to understand and evaluate how the management of the agricultural system will affect establishment before introduction of “biofertilizers”, which is often unpredictable.

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Elucidating the Mechanisms Underlying Enhanced Drought Tolerance in Plants Mediated by Arbuscular Mycorrhizal Fungi

Frontiers in Microbiology ◽

10.3389/fmicb.2021.809473 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shen Cheng ◽

Ying-Ning Zou ◽

Kamil Kuča ◽

Abeer Hashem ◽

Elsayed Fathi Abd_Allah ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Mycorrhizal Fungi ◽

Host Plants ◽

Molecular Mechanisms ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Host Cells ◽

Future Research ◽

Symbiotic Association

Plants are often subjected to various environmental stresses during their life cycle, among which drought stress is perhaps the most significant abiotic stress limiting plant growth and development. Arbuscular mycorrhizal (AM) fungi, a group of beneficial soil fungi, can enhance the adaptability and tolerance of their host plants to drought stress after infecting plant roots and establishing a symbiotic association with their host plant. Therefore, AM fungi represent an eco-friendly strategy in sustainable agricultural systems. There is still a need, however, to better understand the complex mechanisms underlying AM fungi-mediated enhancement of plant drought tolerance to ensure their effective use. AM fungi establish well-developed, extraradical hyphae on root surfaces, and function in water absorption and the uptake and transfer of nutrients into host cells. Thus, they participate in the physiology of host plants through the function of specific genes encoded in their genome. AM fungi also modulate morphological adaptations and various physiological processes in host plants, that help to mitigate drought-induced injury and enhance drought tolerance. Several AM-specific host genes have been identified and reported to be responsible for conferring enhanced drought tolerance. This review provides an overview of the effect of drought stress on the diversity and activity of AM fungi, the symbiotic relationship that exists between AM fungi and host plants under drought stress conditions, elucidates the morphological, physiological, and molecular mechanisms underlying AM fungi-mediated enhanced drought tolerance in plants, and provides an outlook for future research.

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Shelf Life Studies of Seed Coat Formulation of Rhizobium and Arbuscular Mycorrhizal Fungus (AMF) for Pulses - A New Perspective in Biofertilizer Technology

Indian Journal of Agricultural Research ◽

10.18805/ijare.a-5543 ◽

2021 ◽

Author(s):

K. Kumutha ◽

R. Parimala Devi ◽

P. Marimuthu ◽

R. Krishnamoorthy

Keyword(s):

Shelf Life ◽

Seed Coat ◽

Mycorrhizal Fungi ◽

Room Temperature ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Viable Count ◽

Spore Count ◽

One Year

Background: Arbuscular Mycorrhizal Fungi (AMF) and Rhizobium are beneficial plant partners exhibiting mutual association with crop plants. Conventional carrier based formulation has lesser population and limited shelf life. Present study was aimed to evaluate and to assess the shelf life in new formulation as well as in coated seeds under storage.Methods: Three experiments are conducted in this study. Population of Rhizobium and AM fungi spore count were assessed in newer seed coat formulation under room temperature storage. Secondly survival of these organisms on the coated seeds of blackgram and greengram were evaluated. In third experiment the coated seeds stored for different duration were evaluated for germination, growth and vigour index.Result: Rhizobial population was maintained at 1011 g-1 and AM spore load was 900-1000 spores g-1 up to one year of storage. AM spore count was also found sufficient up to 9 months of storage in coated seeds of both crops. Growth and vigour index were significantly enhanced in inoculated plants over uninoculated control. From the study, it was evident that these formulations can be stored upto one year at room temperature without any loss in viable count and can be used for seed coating.

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Growth responses of sugarcane to mycorrhizal spore density and phosphorus rate

Australian Journal of Agricultural Research ◽

10.1071/ar04185 ◽

2005 ◽

Vol 56 (12) ◽

pp. 1405 ◽

Cited By ~ 7

Author(s):

R. M. Kelly ◽

D. G. Edwards ◽

J. P. Thompson ◽

R. C. Magarey

Keyword(s):

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Spore Density ◽

Yield Response ◽

Yield Reduction ◽

Growth Responses ◽

Root Colonisation ◽

P Concentration

Arbuscular mycorrhizal (AM) fungi, commonly found in long-term cane-growing fields in northern Queensland, are linked with both negative and positive growth responses by sugarcane (Saccharum spp.), depending on P supply. A glasshouse trial was established to examine whether AM density might also have an important influence on these growth responses. Mycorrhizal spores (Glomus clarum), isolated from a long-term cane block in northern Queensland, were introduced into a pasteurised low-P cane soil at 5 densities (0, 0.06, 0.25, 1, 4 spores/g soil) and with 4 P treatments (0, 8.2, 25, and 47 mg/kg). At 83 days after planting, sugarcane tops responded positively to P fertilizer, although responses attributable to spore density were rarely observed. In one case, addition of 4 spores/g led to a 53% yield response over those without AM at 8 mg P/kg, or a relative benefit of 17 mg P/kg. Root colonisation was reduced for plants with nil or 74 mg P/kg. For those without AM, P concentration in the topmost visible dewlap (TVD) leaf increased significantly with fertiliser P (0.07 v. 0.15%). However, P concentration increased further with the presence of AM spores. Irrespective of AM, the critical P concentration in the TVD leaf was 0.18%. This study confirms earlier reports that sugarcane is poorly responsive to AM. Spore density, up to 4 spores/g soil, appears unable to influence this responsiveness, either positively or negatively. Attempts to gain P benefits by increasing AM density through rotation seem unlikely to lead to yield increases by sugarcane. Conversely, sugarcane grown in fields with high spore densities and high plant-available P, such as long-term cane-growing soils, is unlikely to suffer a yield reduction from mycorrhizal fungi.

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Inter- and Intraspecific Variability in Infectivity and Effectiveness of Five Glomus sp . Strains and Growth Response of Tomato Host

Agrokémia és Talajtan ◽

10.1556/agrokem.55.2006.1.27 ◽

2006 ◽

Vol 55 (1) ◽

pp. 251-260 ◽

Cited By ~ 1

Author(s):

Tünde Takács ◽

I. Biró ◽

A. Anton ◽

He Chaoxing

Keyword(s):

Plant Growth ◽

Nutrient Uptake ◽

Biomass Production ◽

Glomus Mosseae ◽

Am Fungi ◽

Climatic Conditions ◽

Growth Responses ◽

Terrestrial Plants ◽

Mycorrhizal Dependency ◽

Mean Values

Arbuscular mycorrhizal (AM) fungi are obligatory biotrophic symbionts living in the roots of most terrestrial plants. AM fungi (AMF) have a positive effect on plant growth and plant nutrition, especially under stress conditions. The aim of the present study was to observe the relationship between the mycorrhizal dependency and nutrient uptake of host plants and the rate of AMF colonization in a pot experiment. The degree of host growth responses to AMF colonization is expressed as mycorrhizal dependency (MD). The pot trial was set up with a sterilized calcareous chernozem soil from Nagyhörcsök (Hungary) in a growth chamber under controlled climatic conditions. Tomato (Lycopersicon esculentum L.) plants were inoculated with Glomus claroideum (BEG23) , Glomus fasciculatum (BEG53), Glomus geosporum (BEG11), Glomus mosseae (BEG12) strains and a Glomus mosseae AMF culture produced by authors. The dry biomass production, the micro- and macronutrient concentrations of the shoots and the parameters of the mycorrhizal infection were determined. Each AM fungi species or isolate caused different and distinct changes in host plant growth and nutrient uptake. The biomass production of tomato increased significantly in the presence of AM symbiosis. The mean values of MD, calculated from shoot dry matter, varied between 36% and 55%. Mycorrhizal inoculation improved the P, N and K uptake of tomato. The highest values for root colonization, frequency of infection or arbuscular richness were found in the root of tomato inoculated with the two Glomus mosseae strains. The highest MD and nutrient contents appeared in the shoot of tomato treated withour Glomus mosseae strain, which may indicate a stronger affinity (compatibility) between the symbiotic partners. The results confirmed that the selected AMF strains are applicable in sustainable horticulture.

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Long-term effect of heavy metal loads on the mycorrhizal colonization and metal uptake of barley

Agrokémia és Talajtan ◽

10.1556/agrokem.59.2010.1.21 ◽

2010 ◽

Vol 59 (1) ◽

pp. 175-184

Author(s):

B. Biró ◽

A. Füzy ◽

K. Posta

Keyword(s):

Host Plant ◽

Root System ◽

Biomass Production ◽

Contaminated Soils ◽

Mycorrhizal Fungi ◽

Root Biomass ◽

Infection Intensity ◽

Arbuscular Mycorrhizal ◽

Am Fungi

A pot experiment was designed to study the colonization of indigenous arbuscular mycorrhizal fungi (AMF) on barley ( Hordeum vulgare L.) host plant. Soils of the pots were collected from a long-term field microelement loading experiment on calcareous chernozem soil twelve years after 13 heavy metals (Al, As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sr and Zn) were applied once in four doses (0, 30, 90 and 270 mg element·kg -1 d.w.). The biomass production and element accumulation of the host plant, the various colonization values of the arbuscular mycorrhiza fungi (AMF) – such as colonization intensity (M %), arbusculum richness (A %) in the root system and the sporulation intensity (g -1 dry soil) in the rhizosphere – were measured. When considering the twelve-year adaptation process of the AM fungal populations at the various metal loads, a relatively balanced inside mycorrhiza colonization was found, suggesting the potentials for the selection of tolerant fungi in metal contaminated soils. The balanced infection intensity (M %) of the AM fungi and their common strategies with the host plant have resulted a nonsignificant shoot and root biomass production of barley in general. Mycorrhiza sporulation in the root system proved to be much variable and indicated the toxicity of metals and metal rates. Cd, Pb and Sr elements significantly reduced spore numbers, while a value of 34 spores·g -1 soil was counted in the case of Ni in comparison to the control’s 22 spores·g -1 soil value. Stress-defending strategies of the fungal–plant symbiosis, such as the increased arbusculum richness (A %) could be established for the Hg and Pb rates. In the case of Cd an increased root biomass production became a tool for stress alleviation and reduced the metal allocation towards the shoots. Mycorrhiza fungi are part of the common plant–microbe interactions and appropriate defending mechanisms in metal contaminated soils.

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Ectomycorrhizal Fungal Inoculation of Sphaerosporella brunnea Significantly Increased Stem Biomass of Salix miyabeana and Decreased Lead, Tin, and Zinc, Soil Concentrations during the Phytoremediation of an Industrial Landfill

Journal of Fungi ◽

10.3390/jof6020087 ◽

2020 ◽

Vol 6 (2) ◽

pp. 87 ◽

Cited By ~ 3

Author(s):

Dimitri J. Dagher ◽

Frédéric E. Pitre ◽

Mohamed Hijri

Keyword(s):

Trace Element ◽

Mycorrhizal Fungi ◽

Plant Biomass ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Symbiotic Associations ◽

Growing Seasons ◽

Abiotic Stressors ◽

Sphaerosporella Brunnea ◽

Am Fungus

Fast growing, high biomass willows (Salix sp.) have been extensively used for the phytoremediation of trace element-contaminated environments, as they have an extensive root system and they tolerate abiotic stressors such as drought and metal toxicity. Being dual mycorrhizal plants, they can engage single or simultaneous symbiotic associations with both arbuscular mycorrhizal (AM) fungi and ectomycorrhizal (EM) fungi, which can improve overall plant health and growth. The aim of this study was to test the effect of these mycorrhizal fungi on the growth and trace element (TE) extraction potential of willows. A field experiment was carried out where we grew Salix miyabeana clone SX67 on the site of a decommissioned industrial landfill, and inoculated the shrubs with an AM fungus Rhizophagus irregularis, an EM fungus Sphaerosporella brunnea, or a mixture of both. After two growing seasons, the willows inoculated with the EM fungus S. brunnea produced significantly higher biomass. Ba, Cd and Zn were found to be phytoextracted to the aerial plant biomass, where Cd presented the highest bioconcentration factor values in all treatments. Additionally, the plots where the willows received the S. brunnea inoculation showed a significant decrease of Cu, Pb, and Sn soil concentrations. AM fungi inoculation and dual inoculation did not significantly influence biomass production and soil TE levels.

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Pengaruh Independensi, Kompetensi, Dan Pengalaman Kerja Auditor Terhadap Kualitas Audit

Jurnal ULTIMA Accounting ◽

10.31937/akuntansi.v4i2.133 ◽

2012 ◽

Vol 4 (2) ◽

pp. 91-110

Author(s):

Caroline Sytha Sunarta ◽

Suhajar Wiyoto

Keyword(s):

Audit Quality ◽

Multiple Regression Model ◽

Future Research ◽

Survey Area ◽

Process Data ◽

External Auditors ◽

Job Experience ◽

Independent Variables ◽

One Year ◽

Public Accountant

The objective of this research is to examine the effect of auditor’s independency, competency, and job experience towards audit quality.This research is conducted by using method survey to public accountants (external auditors) that working settled in Public Accountant Firm (KAP) in Jakarta and Tangerang, in 2012 and have one year minimum experience, as respondents with type research of causality. Using likert scale as an instrument (questionaire) for measure auditor’s perceptions about the independency, competency, and job experience that influence audit quality. From 150 questionaire distributed, returned was 109 questionaire, and 24 not complete, so that only 85 questionaire could be process. Data analysis conducted with multiple regression model. The hypotheses tested are revealed as that independency, competency, and job experience have influence to audit quality as well as partially and simultaneously. The result of the test showed empirical testimony that auditor’s independency, competency, and job experience as well as simultaneously significantly influence audit quality. Partially, independency, competency, and job experience also have significant influence to audit quality. Future research expected can extend survey area coverage and add more independent variables that can have influence to audit quality. Keywords: independency, competency, job experience, audit quality.

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Growth Responses of Boreal Scots Pine, Norway Spruce and Silver Birch Seedlings to Simulated Climate Warming over Three Growing Seasons in a Controlled Field Experiment

Forests ◽

10.3390/f11090943 ◽

2020 ◽

Vol 11 (9) ◽

pp. 943

Author(s):

Katri Nissinen ◽

Virpi Virjamo ◽

Antti Kilpeläinen ◽

Veli-Pekka Ikonen ◽

Laura Pikkarainen ◽

...

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

Root Biomass ◽

Growing Season ◽

Silver Birch ◽

Shoot Biomass ◽

Growth Responses ◽

Growing Seasons ◽

Simulated Climate ◽

Shoot And Root Biomass

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.

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Tracking of Zinc Ferrite Nanoparticle Effects on Pea (Pisum sativum L.) Plant Growth, Pigments, Mineral Content and Arbuscular Mycorrhizal Colonization

Plants ◽

10.3390/plants10030583 ◽

2021 ◽

Vol 10 (3) ◽

pp. 583

Author(s):

Reda E. Abdelhameed ◽

Nagwa I. Abu-Elsaad ◽

Arafat Abdel Hamed Abdel Latef ◽

Rabab A. Metwally

Keyword(s):

Pisum Sativum ◽

Plant Growth ◽

Zinc Ferrite ◽

Crop Improvement ◽

Nanocrystalline Structure ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Transmission Electron ◽

Agricultural Applications ◽

The Impact

Important gaps in knowledge remain regarding the potential of nanoparticles (NPs) for plants, particularly the existence of helpful microorganisms, for instance, arbuscular mycorrhizal (AM) fungi present in the soil. Hence, more profound studies are required to distinguish the impact of NPs on plant growth inoculated with AM fungi and their role in NP uptake to develop smart nanotechnology implementations in crop improvement. Zinc ferrite (ZnFe2O4) NPs are prepared via the citrate technique and defined by X-ray diffraction (XRD) as well as transmission electron microscopy for several physical properties. The analysis of the XRD pattern confirmed the creation of a nanocrystalline structure with a crystallite size equal to 25.4 nm. The effects of ZnFe2O4 NP on AM fungi, growth and pigment content as well as nutrient uptake of pea (Pisum sativum) plants were assessed. ZnFe2O4 NP application caused a slight decrease in root colonization. However, its application showed an augmentation of 74.36% and 91.89% in AM pea plant shoots and roots’ fresh weights, respectively, compared to the control. Moreover, the synthesized ZnFe2O4 NP uptake by plant roots and their contents were enhanced by AM fungi. These findings suggest the safe use of ZnFe2O4 NPs in nano-agricultural applications for plant development with AM fungi.

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