Indigenous Arbuscular Mycorrhizal Fungi Research Articles

Effect of Indigenous and Introduced Arbuscular Mycorrhizal Fungi on Growth and Phytochemical Content of Vegetatively Propagated Prunus Africana (Hook. f.) Kalkman Provenances.

Prunus africana bark contains phytochemical compounds used in the treatment of benign prostatic hyperplasia and prostate cancer. It has been shown that this plant establishes association with arbuscular mycorrhizal fungi (AMF). AMF are involved in nutrient uptake, which may also affect plant growth and secondary metabolites composition. However, there is no information regarding the role of AMF in the growth and phytochemical content of P. africana. A pot experiment was carried out to assess the response of 8 months old vegetatively propagated P. africana seedlings inoculated with indigenous AMF collected from Mount Cameroon (MC) and Mount Manengumba (MM) in Cameroon, Malava near Kakamega (MK) and Chuka Tharaka-Nithi (CT) in Kenya. Mycorrhizal (frequency, abundance and intensity), growth (height, shoot weight, total weight, number of leaf, leaf surface) and phytochemical (total phenol, tannin and flavonoids) parameters were measured three months after growth of seedlings from two provenances (Muguga and Chuka) with the following inoculation treatments: MK, CT, MC, MM, non-sterilized soil (NS) and sterilized sand as non-inoculated control. Results showed that seedling heights were significantly increased by inoculation and associated with high root colonization (>80%) compared to non-inoculated seedlings. We also found that AMF promoted leaf formation, whereas inoculation did not have any effect on the seedling total weight. AMF inoculum from MM had a higher tannin content, while no significant difference was observed on the total phenol and flavonoid contents due to AMF inoculation. Pearson’s correlation was positive between mycorrhizal parameters and the growth parameters, and negative with phytochemical parameters. This study is the first report on the effect of AMF on the growth and phytochemical in P. africana. Further investigations are necessary to determine the effect of single AMF strains to provide better understanding of the role of AMF on the growth performance and physiology of this important medicinal plant species.

The Current Survey of Indigenous Arbuscular Mycorrhizal Fungi of Wheat (Triticum aestivum) in Benghazi’s Coastal Plain

Rhizospheres of crop plants are complexes of chemical and microbial interactions. Of importance, arbuscular mycorrhizal fungi (AMF) are beneficial microorgansims associated with roughly eighty-percent of terrestrial land plants. In this mutualistic symbiosis, the fungus receives the photosynthetic product (sugar) fixed from its host by photosynthesis. In return, the host plant gains a plethora of benefits from the fungus such as enhanced nutrient uptakes, protection against both biotic (soil-borne root pathogens, insect attack) and abiotic (drought, heavy metal pollution, and soil salinity) stresses. Taxonomically, AMF belong to a new erected phylum called Glomeromycota. The field study was conducted in a farm owned and supervised by The Great Man-Made Project in February 2019. The present study was performed to determine the presence or the absence of AMF in a field cultivated with wheat crops (Triticum aestivum, L.) during the vegetative stage, and also to investigate soil physiochemical properties effect on AMF colonization. Results showed that colonization of wheat plant roots were significantly low. The result clearly implies that high-input fertilizers viz., phosphorus fertilization, and agricultural practices such as intensive tillage drastically reduced AMF colonization.

Could indigenous arbuscular mycorrhizal communities be used to improve tolerance of pistachio to salinity and/or drought?

Arbuscular mycorrhizal fungi (AMF) establish symbiosis with a number of plant species, including pistachio, under a broad range of soil conditions. Here we present a fully factorial pot experiment where four different indigenous AMF communities (two with high- and two with low-salinity legacies) were tested for improving pistachio seedling tolerance to salinity and/or drought in terms of maintaining its growth and/or mineral (phosphorus and zinc) nutrition under experimentally applied abiotic stress. The AMF communities were pre-cultured with a grass to reduce the load of pistachio pathogens before application to the seedlings. We detected systematic improvement of pistachio mineral nutrition by the AMF communities, whereas salinity and drought generally suppressed pistachio performance independently of each other. The AMF communities from saline soils systematically improved pistachio tolerance to salinity in terms of maintaining higher phosphorus acquisition of their host, whereas their effect on maintaining plant zinc nutrition under high salinity was less prominent. The effects of the different AMF communities on pistachio tolerance to drought were variable and without obvious link to the environmental legacy of the AMF. One of the AMF communities from saline soil (dominated by Rhizophagus) showed particular tolerance to salinity in terms of maintaining high colonization rates of pistachio roots. Interestingly, one of the AMF communities from low-salinity soils conferred a significant tolerance of pistachio to salinity in terms of maintaining its phosphorus acquisition upon the stress. This means that beneficial traits of plant symbiotic microbes may occur uncoupled from the selective pressure in their native range.

Soil-indigenous arbuscular mycorrhizal fungi and zeolite addition to soil synergistically increase grain yield and reduce cadmium uptake of bread wheat (through improved nitrogen and phosphorus nutrition and immobilization of Cd in roots).

Soil pollution with heavy metals is a major problem in industrial areas. Here, we explored whether zeolite addition to soil and indigenous arbuscular mycorrhizal fungi (AMF) can reduce cadmium (Cd) uptake from soil by bread wheat. We conducted a pot experiment, in which the effects of indigenous soil AMF, zeolite addition, and Cd spiking to soil [0, 5, 10, and 15 mg (kg soil)-1] were tested. Zeolite addition to soil spiked with 15 mg Cd kg-1 decreased the Cd uptake to grains from 11.8 to 8.3 mg kg-1 and 8.9 to 3.3 mg kg-1 in the absence and presence of indigenous AMF, respectively. Positive growth, nitrogen (N), and phosphorous (P) uptake responses to mycorrhization in Cd-spiked soils were consistently magnified by zeolite addition. Zeolite addition to soil stimulated AMF root colonization. The abundance of AMF taxa changed in response to zeolite addition to soil and soil Cd spiking as measured by quantitative polymerase chain reaction. With increasing Cd spiking, the abundance of Funneliformis increased. However, when less Cd was spiked to soil and/or when zeolite was added, the abundance of Claroideoglomus and Rhizophagus increased. This study showed that soil-indigenous AMF and addition of zeolite to soil can lower Cd uptake to the grains of bread wheat and thereby reduce Cd contamination of the globally most important staple food.

Sunflower response to inoculation with single and mixed species of arbuscular mycorrhizal fungi: Agronomic characteristics

The impact of indigenous arbuscular mycorrhizal fungi (AMF) on agronomic characteristics of sunflower (Helianthus annuus L.) was evaluated in a pot experiment. The indigenous AMF, including Glomus intraradices, Glomus mosseae, and Glomus viscosum, were isolated from an agricultural field in which cotton and sunflower plants were grown. The most abundant species (G. viscosum) was multiplied in a monospecific culture. Sunflower plants were inoculated with the mixture of three selected AMF species or solely with G. viscosum. The number of leaves, shoot length, head diameter, above ground biomass, and seeds mass were significantly higher in the plant inoculated with AMF mixture followed by individual inoculation with G. viscosum followed by the control. AMF mixture outperformed the G. viscosumby increasing mycorrhizal dependency and mycorrhizal inoculation effect of sunflower. The results indicate that AMF mixture could be considered as a good inoculum for improving growth and yield of sunflower in sustainable agriculture.

Development of propagation technique of indigenous AMF and their inoculation response in citrus

Arbuscular mycorrhizal fungi (AMF) have multi-pronged utility in citrus performance, while their propagation technique is a gap. In this study, indigenous AMF in rhizosphere of Citrus unshiu grafted on trifoliate orange were isolated from fresh root segments (Φ<2 mm), fresh rhizosphere soil (< 4 mm size), and air-dried rhizosphere soil (< 4 mm size) as AMF-source and propagated with white clover. Subsequently, indigenous AMF inocula were inoculated into potted trifoliate orange to assess the inoculated efficiency. Our results showed that AMF isolated from fresh root segments multiplied by 333.9% significantly higher than those isolated from fresh or air-dried rhizosphere soil. Similar results were obtained with regard to root mycorrhizal colonization (37.16–55.41%) and soil hyphal length (3.88–13.38 cm/g) in trifoliate orange after inoculated with AMF-source from root segments. Mycorrhizal trifoliate orange seedlings carrying AMF inoculum from fresh roots exhibited higher plant growth performance, root morphology, leaf P, K, Mg, Cu and Zn levels, and leaf superoxide dismutase, peroxidase, and catalase activities, compared to non-AMF treatment. Our study, hence, suggested that root segments would be a great choice to propagate indigenous AMF for later inoculating into the rhizosphere of target plants.

Concomitant biocontrol of pepper Phytophthora blight by soil indigenous arbuscular mycorrhizal fungi via upfront film-mulching with reductive fertilizer and tobacco waste

Both reductive disinfestation and germicide can suppress Phytophthora blight, while soil arbuscular mycorrhizal (AM) fungi also have biocontrol effects on soilborne diseases. However, the combined effects of reductive disinfestation and botanical germicide [e.g., tobacco (Nicotiana tabacum L.) waste] on pepper (Capsicum annuum L.) Phytophthora blight and soil AM fungi are at present unclear. The purposes of this work were to develop application strategy for dealing with pepper Phytophthora blight, and to explore the concomitant contribution from soil indigenous AM fungi. A field experiment with four treatments was carried out in a pepper continuous planting field, including normal film-mulching with common fertilizer (control), normal film-mulching with reductive fertilizer (RF), upfront film-mulching with reductive fertilizer (UM+RF), and upfront film-mulching with reductive fertilizer and tobacco waste (UM+RF+TW). Phytophthora blight severity index, root mycorrhizal colonization rate, and the biomass and nutrient (N, P, and K) concentrations of shoots, roots, and fruits of pepper were measured. Soil pH, organic C, mineral N, available P, available K, acid phosphatase activity, and AM fungal abundance were also tested. The Pearson correlation analysis was carried out among plant and soil parameters. RF tended to increase pepper fruit yield compared with control, and UM+RF tended to decrease Phytophthora blight severity in relative to RF, while UM+RF+TW tended to decrease blight severity and increase fruit yield compared with UM+RF, and had a significantly (P < 0.05) lower blight severity and a significantly higher fruit yield in comparison with control. UM+RF+TW also significantly decreased soil pH, and significantly increased AM fungal population and colonization, as well as soil acid phosphatase activity and available P concentration. In addition, UM+RF+TW had a significantly higher fruit K accumulation ratio, which negatively correlated with blight severity and positively correlated with fruit yield. However, fruit K accumulation ratio positively correlated with fruit P accumulation ratio, which was greatly elevated by the enhanced mycorrhizal colonization. The coalition of reductive disinfestation (upfront film-mulching with reductive fertilizer) and tobacco waste had the greatest suppression of pepper Phytophthora blight, and the highest fruit yield and AM fungal population. It suggests that combined application of reductive disinfestation and botanical germicide has superposition in inhibiting Phytophthora blight and increasing fruit yield, and there seems to be a concomitant biocontrol by soil indigenous AM fungi which could enhance P and K transfer from plant to fruit.

First report of community dynamics of arbuscular mycorrhizal fungi in radiocesium degradation lands after the Fukushima-Daiichi Nuclear disaster in Japan

Arbuscular mycorrhizal fungi (AMF) can be beneficial for improving restoration of radioactive-cesium (137Cs)-contaminated soils through soil remediation. However, there has been no information on species diversity and the composition of AMF communities in 137Cs-contaminated soil after the Fukushima-Daiichi Nuclear Power Plant (NPP) disaster. We examined the community dynamics of indigenous AMF colonizing roots of napiergrass (Pennisetum purpureum) in two different 137Cs-contaminated land-use fields (grassland and paddy field) by an Illumina MiSeq sequencing investigation within a 30-km radius around the Fukushima-Daiichi NPP in 2013 (sampling year 1) and 2014 (sampling year 2). We found nine AMF families, including Glomeraceae, Gigasporaceae, Paraglomeraceae, Claroideoglomeraceae, Acaulosporaceae, Archeosporaceae, Ambisporaceae, Diversisporaceae and uncultured Glomeromycotina in roots. Glomeraceae was the most abundant in both grassland and paddy field, followed by Paraglomeraceae. The diversity of AMF in grassland and paddy field was higher in 2014 than in 2013. Furthermore, the AMF community structure was impacted by sampling year and land-use type. The AMF community structures colonizing napiergrass roots were also significantly impacted by land-use type and year throughout the 2-year investigation. To our knowledge, our results are the first report to reveal the community dynamics of indigenous AMF in the 137Cs-contaminated fields around NPP.

Arbuscular Mycorrhizal Fungi Alleviate Drought Stress in C3 (Leymus chinensis) and C4 (Hemarthria altissima) Grasses via Altering Antioxidant Enzyme Activities and Photosynthesis.

As one of the most important limiting factors of grassland productivity, drought is predicted to increase in intensity and frequency. Greenhouse studies suggest that arbuscular mycorrhizal fungi (AMF) can improve plant drought resistance. However, whether AMF can improve plant drought resistance in field conditions and whether the effects of AMF on drought resistance differ among plants with different photosynthetic pathways remain unclear. To evaluate the effect of indigenous AMF on plant drought resistance, an in situ rainfall exclusion experiment was conducted in a temperate meadow in northeast China. The results showed that AMF significantly reduced the negative effects of drought on plant growth. On average, AMF enhanced plant biomass, photosynthetic rate (A), stomatal conductance (gs), intrinsic water use efficiency (iWUE), and superoxide dismutase (SOD) activity of the C3 species Leymus chinensis by 58, 63, 38, 15, and 45%, respectively, and reduced levels of malondialdehyde (MDA) by 32% under light and moderate drought (rainfall exclusion of 30 and 50%, respectively). However, under extreme drought (rainfall exclusion of 70%), AMF elevated only aboveground biomass and catalase (CAT) activities. Averagely, AMF increased the aboveground biomass, A, and CAT activity of Hemarthria altissima (C4) by 37, 28, and 30%, respectively, under light and moderate droughts. The contribution of AMF to plant drought resistance was higher for the C3 species than that for the C4 species under both light and moderate drought conditions. The results highlight potential photosynthetic type differences in the magnitude of AMF-associated enhancement in plant drought resistance. Therefore, AMF may determine plant community structure under future climate change scenarios by affecting the drought resistance of different plant functional groups.

Exploration of Indigenous Arbuscular Mycorrhizal Fungi on Post Mining Soil as Rehabilitation Strategy

Exploration of Indigenous Arbuscular Mycorrhizal Fungi on Post Mining Soil as Rehabilitation Strategy

Wheat landraces with low mycorrhizing ability at field respond differently to inoculation with artificial or indigenous arbuscular mycorrhizal fungal communities

Conventional farming is not sustainable in a context of climate change and of dramatic reductions in natural resource stocks worldwide. A change of paradigm towards more sustainable farming is necessary, based on the preservation and management of ecosystem services. The soil is a reservoir of organisms beneficial for plant production. Among these are arbuscular mycorrhizal fungi. Nevertheless, the response of plants – especially cereal landraces – to mycorrhization, and the effect of domestication on the response to mycorrhization are controversial. In the present paper we investigated the response of four wheat landraces with a low mycorrhizogenous ability to inoculation with the indigenous arbuscular mycorrhizal fungi community or an artificial community in greenhouse and field conditions. We showed that the community of arbuscular mycorrhizal fungi can have an effect on yield, even in wheat landraces with a low mycorrhizogenous ability. We also highlighted the importance to properly choose the criteria (phenotypic criteria as root and shoot biomasses versus quality criteria as grain quality) used to measure this possible gain.

Optimization of a Novel Vegetable Nursery Substrate Using Date Palm Wastes Peat and Indigenous Arbuscular Mycorrhizal Fungi

ABSTRACTQuality of vegetable seedlings is affected by nursery management practices, essentially growing media. For sustainable greenhouse horticulture, it is important to characterize biologically based approaches to improve plantlet quality. Here, we investigate the possibility of developing a biotized growth substrate for nursery production using date palm wastes (DPWs) peat as an alternative to commercial sphagnum peat and indigenous arbuscular mycorrhizal fungi (AMF). A greenhouse experiment was established using different rates of DPWs peat to substitute commercial peat in both conventional and organic nursery production systems. Lettuce seedlings were inoculated or not with native AMF isolated from plots with conventional or organic production system (CM and OM respectively). When lettuce plantlets attained commercial size, a microscopic observation revealed that the establishment of mycorrhizal association was successful in all mixtures of growing media. Significant increase in growth parameters (height shoot, number and area of leaves, shoot and root biomass) were observed on plantlets inoculated with indigenous AMF isolated from organic plot compared to those isolated from conventional plot and to control (without AMF). Commercial peat partial substitution with DPWs peat in proportion of 25–50% improves better lettuce performance than complete-peat use. Consequently, these mixtures seem to be an appropriate formulation for sustainable nursery production.

The cover crop determines the AMF community composition in soil and in roots of maize after a ten-year continuous crop rotation

Intensive agricultural practices are responsible for soil biological degradation. By stimulating indigenous arbuscular mycorrhizal fungi (AMF), cover cropping enhances soil health and promotes agroecosystem sustainability. Still, the legacy effects of cover crops (CCs) and the major factors driving the AM fungal community are not well known; neither is the influence of the specific CC. This work describes a field experiment established in Central Spain to test the effect of replacing winter fallow by barley (Hordeum vulgare L.) or vetch (Vicia sativa L.) during the intercropping of maize (Zea mays L.). We examined the community composition of the AMF in the roots and rhizosphere soil associated with the subsequent cash crop after 10 years of cover cropping, using Illumina technology. The multivariate analysis showed that the AMF communities under the barley treatment differed significantly from those under fallow, whereas no legacy effect of the vetch CC was detected. Soil organic carbon, electrical conductivity, pH, Ca and microbial biomass carbon were identified as major factors shaping soil AMF communities. Specific AMF taxa were found to play a role in plant uptake of P, Fe, Zn, Mn, and Cd, which may shed light on the functionality of these taxa. In our conditions, the use of barley as a winter CC appears to be an appropriate choice with respect to promotion of AMF populations and biological activity in agricultural soils with intercropping systems. However, more research on CC species and their legacy effect on the microbial community composition and functionality are needed to guide decisions in knowledge-based agriculture.

Arbuscular mycorrhizal fungi in the rhizosphere soil of poisonous plants depressed the growth of pasture grasses in the Tibetan Plateau Alpine meadow

ABSTRACT In order to explore the influence of arbuscular mycorrhizal (AM) fungi in the rhizosphere of poisonous plants on the neighboring pasture grasses in the Tibetan Plateau Alpine meadow ecosystem, rhizosphere soils were collected from eight different poisonous plants in degraded grasslands and one from pasture grass in non-degraded grasslands (CK). The collected soils were used as inocula to assess the influence of indigenous AM fungi on the growth of two typical pasture grass species, Elymus nutans and Poa pratensis, in a bioassay experiment. Five growth parameters and two AM parameters were determined. The mycorrhizal responsiveness and the importance value were calculated. Significant differences between the eight poisonous plants and CK were observed. Compared to CK, rhizosphere soil from the eight poisonous plants had lower AM fungal spore densities. The growth of E. nutans and P. pratensis seedlings was depressed with the inoculation from poisonous plants rhizosphere soil. This study demonstrated that the presence of poisonous plants with grassland degradation altered inherent AM fungal community abundance, and could exert inhibition effects on the growth of pasture grasses. It may attribute to discover the important role of rhizosphere soil of different poisonous plants to AM fungal community on the Alpine meadow.

Biocontrol of Foot and Root Rot Disease of Grasspea (Lathyrus sativus) by Dual Inoculation with Rhizobium and Arbuscular Mycorrhiza

The present study was carried out to evaluate the effect of indigenous arbuscular mycorrhizal fungi (AMF) and Rhizobium (R) on plant growth and their biocontrol against grasspea foot and root rot disease caused by Sclerotium rolfsii. The bio-control potential of these bio-agents against foot and root rot pathogen was carried out under pot culture condition using AMF alone or in combination with rhizobial inoculum in the nethouse of Soil Science Division, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during 2014-2015 through 2015-2016. The experiment was designed in RCBD with 8 treatments and 4 replications. Grasspea variety BARI Khesari-1 was used as a test crop. Peat based rhizobial inoculum (BARI RLs-10) was used in this experiment @ 50 g kg-1 seed. The AM fungi used in this experiment were Glomus fusianum, Glomus macrocarpum, Glomus warcuppi, Acaulospora foveata, Acaulospora denticulate, Gigaspora albida, Gigaspora rosea, Glomus spp. etc. Soil based AM inoculum containing about approximate 252 spores and infected root pieces of the host plant was used pot-1. There were eight treatments viz. T1: Arbuscular mycorrhiza (AM), T2: Rhizobium, T3: AM + Rhizobium, T4: Sclerotium rolfsii, T5: Sclerotium rolfsii + AM, T6: Sclerotium rolfsii + Rhizobium, T7: Sclerotium rolfsii + AM + Rhizobium and T8: Control. Dual inoculation (AM + Rhizobium) increased 20-25% germination, 50-100% seed yield and 36-98% stover yield compared to control. Dual inoculation reduced 44-48% foot and root rot disease compared to control. On the contrary, Sclerotium rolfsii + Rhizobium, Sclerotium rolfsii + AM, and Sclerotium rolfsii + AM + Rhizobium reduced 12-17%, 16-20% and 28-31% foot and root rot disease, respectively compared to only Sclerotium rolfsii trearment. Therefore, arbuscular mycorrhizal fungal species and its combination with rhizobial inoculum were significant both in the formation and effectiveness of AM symbiosis and the reduction of foot and root rot incidence in grasspea plants. Use of these bio-control agents could be promoted as an active component of bio-intensive Integrated Disease Management Program (IDMP) under organic mode.&#x0D; Bangladesh J Microbiol, Volume 34 Number 2 December 2017, pp 109-117

Influence of indigenous arbuscular mycorrhizal fungus and bacterial bioinoculants on growth and yield ofCapsicum chinensecultivated in non-sterilized soil

AbstractDespite the global importance ofCapsicumspecies, there is limited information on the indigenous endomycorrhizal fungal association in this crop. Therefore, the diversity and colonization patterns of arbuscular mycorrhizal fungi (AMF) in roots of Naga King chilli (Capsicum chinense) were assessed during pre-flowering, flowering and fruit ripening growth stages under a sub-tropical shifting cultivation system of North Eastern India. All the roots examined had AMF colonization and the presence ofParis-type arbuscular mycorrhizal morphology is reported for the first time inC. chinense. A total of 11 AMF spore morphotypes were isolated from both field and trap culture soils. Maximum AMF spore density and root colonization were recorded during the pre-flowering and flowering stages, respectively. The influence ofFunneliformis geosporum, individually or in combination withPseudomonas fluorescensandAzotobacter chroococcum, on growth and yield ofC. chinense, was evaluated in a pot experiment using sterilized and non-sterilized soils. The application of AMF andP. fluorescensto sterilized soil significantly increased the growth, flower and fruit production, and nutrient content ofC. chinense. The highest growth rates and yields ofC. chinensein non-sterilized soils were achieved when AMF was combined with bothP. fluorescensandA. chroococcum. The results of the current study indicate the value of applying microorganisms to improve plant growth and performance in chillies. One of the mechanisms for this could be the facilitated assimilation of nutrients promoted by AMF and bacterial bioinoculants.

Screening mined-out indigenous mycorrhizal fungi for the rehabilitation of mine tailing areas in the Philippines

Arbuscular mycorrhizal fungi (AMF) play a significant role for mine tailing rehabilitation due to their sensitivity towards a range of soil pollutants. This beneficial biological agent can enhance plant tolerance to heavy metal contamination. This study screened indigenous AMF associated with growing indigenous ferns and grasses in the mine tailings for potential use in rehabilitating a 3-decade abandoned mined out area in Mogpog, Marinduque. Pterocarpus indicus Willd. (narra) was used as the host plant to establish mycorrhizal fungi association. Among the treatments, indigenous AMF associated with Ferns 1, 2 and 5 generally improved the height and shoot diameter of the narra seedlings and the effect was comparable with commercially available AMF inoculants, MYKOVAM® and MYKORICH®. The dry weight of the roots and nodules was consistently improved by indigenous AMF from Fern2 and Grass1, which had comparable effect with MYKOVAM® and MYKORICH®. Overall, the total seedling dry matter of narra seedlings was significantly stimulated by AMF, irrespective of isolates’ origin. The mycorrhizal root infection by AMF and number of spores in the soil were all high as compared with the uninoculated control counterpart. Lastly, AMF inoculation induced Cu retention in the roots of the seedlings. Thus the results imply that, the mined out indigenous AMF are potential agents to rehabilitate the abandoned mine tailings in the Philippines.

Impact of Introduction of Arbuscular Mycorrhizal Fungi on the Root Microbial Community in Agricultural Fields.

Arbuscular mycorrhizal (AM) fungi are important members of the root microbiome and may be used as biofertilizers for sustainable agriculture. To elucidate the impact of AM fungal inoculation on indigenous root microbial communities, we used high-throughput sequencing and an analytical pipeline providing fixed operational taxonomic units (OTUs) as an output to investigate the bacterial and fungal communities of roots treated with a commercial AM fungal inoculum in six agricultural fields. AM fungal inoculation significantly influenced the root microbial community structure in all fields. Inoculation changed the abundance of indigenous AM fungi and other fungal members in a field-dependent manner. Inoculation consistently enriched several bacterial OTUs by changing the abundance of indigenous bacteria and introducing new bacteria. Some inoculum-associated bacteria closely interacted with the introduced AM fungi, some of which belonged to the genera Burkholderia, Cellulomonas, Microbacterium, Sphingomonas, and Streptomyces and may be candidate mycorrhizospheric bacteria that contribute to the establishment and/or function of the introduced AM fungi. Inoculated AM fungi also co-occurred with several indigenous bacteria with putative beneficial traits, suggesting that inoculated AM fungi may recruit specific taxa to confer better plant performance. The bacterial families Methylobacteriaceae, Acetobacteraceae, Armatimonadaceae, and Alicyclobacillaceae were consistently reduced by the inoculation, possibly due to changes in the host plant status caused by the inoculum. To the best of our knowledge, this is the first large-scale study to investigate interactions between AM fungal inoculation and indigenous root microbial communities in agricultural fields.

The Potential Types of Indigenous Arbuscular Mycorrhizal Fungi as Sources of Inoculum and Their Effect on Rice Production Using the System of Rice Intensification Method

The Potential Types of Indigenous Arbuscular Mycorrhizal Fungi as Sources of Inoculum and Their Effect on Rice Production Using the System of Rice Intensification Method

Effect of Arbuscular Mycorrhizal Fungi on Pratylenchus penetrans Infestation in Apple Seedlings under Greenhouse Conditions.

A major problem in fruit cultivation in Flanders is replant disease due to a lack of uncultivated soils available for new plantings. Replant disease can cause poor growth and affect time to full production, however Arbuscular Mycorrhizal Fungi (AMF) can prove their usefulness with regard to these problems. To further investigate the effect of AMF on nematodes, different AMF species were amended to potted apple seedlings in the presence of the nematode Pratylenchus penetrans. Generally, apple seedlings grew better in the presence of nematodes when mycorrhiza were inoculated into the soil. Moreover, a positive correlation (R2 ≥ 0.88) was found between the percentage root length colonization of the roots of apple seedlings, by AMF species, and nematode reduction in the soil of the seedlings. Indigenous AMF could colonize the roots of apple seedlings the most efficiently, resulting in a higher biocontrol effect. Besides, a synergistic effect was observed when two AMF strains were applied together leading to a significant growth response of the seedlings.