Combination Of Arbuscular Mycorrhizal Fungi Research Articles

Arbuscular mycorrhizal fungi impact on yield attributes, protein quantity and quality in bread wheat (Triticum aestivum L.) grown under drought stress

Drought is increasingly becoming a production constraint in wheat world-wide. Arbuscular mycorrhizal fungi (AMF)-bread wheat symbiosis has been shown to improve the tolerance under drought stress. The objective of this study was to determine the effects of AMF inoculation on yield attributes (spike number per plant, spike weight per plant, number of grains per spike, grain weight per spike and 1000 grain weight) and protein quantity and quality in two bread wheat cultivars (PAN3497 and SST806) grown under drought stress. Plant growth was significantly reduced due to drought stress in both cultivars. Shoot dry weight was significantly increased (23%) due to AMF inoculation in SST806. AMF inoculation caused a further significant increase of protein content in both cultivars (10.70% and 13.42% in PAN3497 and SST806, respectively). Low molecular weight (LMW) glutenin was significantly decreased in PAN3497 under drought stress. However, the monomeric proteins were significantly increased by drought and/or a combination of drought and AMF inoculation in both cultivars. In cultivar SST806, significant reduction of polymeric protein was observed due to application of both AMF (6%) and a combination of AMF with drought stress (4%). Regarding the two-dimensional separation of the gluten proteins, drought had the largest effect on protein spots, with AMF causing up-regulation of only some spots. SST806 was generally more drought tolerant than PAN3497.

Synergistic interplay between arbuscular mycorrhizal fungi and fern manure compost tea suppresses common tomato phytopathogens and pest attacks on-farm

Actually, there are intensive efforts towards eco-friendly integrated agricultural management measures to control plant diseases and pests. One of the most promising approaches is the use of arbuscular mycorrhizal fungi (AMF) in combination with organic biopesticides such as eagle fern manure (FM) compost tea. However, their effects have been mainly studied independently from each other. The potential interactions between belowground plant-associated microorganisms such as AMF and aboveground foliar application of biopesticide to mitigate common tomato phytopathogens and pests remain untapped, particularly under on-farm conditions. In a randomized complete block design, the impact of inoculating tomato seedlings with a selected AMF consortium and beyond that the impact of mycorrhized plants receiving three different doses of FM compost tea (0%, 5%, and 10%) on the control of tomato-specific plant diseases and pests and subsequently on the crop yield were examined. The present study demonstrated a sevenfold increase in the rate of mycorrhizal root colonization (from 10% to 70%) in tomato plants that received the combined application of AMF and 10% FM compost tea compared to the control plants that did not receive AMF inoculum and FM compost tea. The combination of AMF and FM compost tea application led to positive synergistic effects that promoted beneficial effects in suppressing the incidence and severity of common tomato diseases and pests. The magnitude of these synergistic effects increased with AMF inoculation and FM compost tea dosage, culminating in greater suppression of tomato plant diseases and pests and, moreover, in an increase in fruit yield compared to control plants. The combination of AMF and 10% FM compost tea revealed a higher suppressive ability against most pathogens and insect attacks. This was evidenced by a 71.3% and 94.7% total reduction in incidence and severity, respectively, compared to control plants. This is the first time that pre-inoculation of AM, combined with FM compost tea application, has been reported as a potential biocontrol alternative to suppress common tomato pathogens and pests while increasing cherry tomato yields sustainably.

Onion Fusarium Basal Rot Disease Control by Arbuscular Mycorrhizal Fungi and Trichoderma harzianum

Soilborne pathogens reduce 60% of the yield of onion crops. A common fungal pathogen causing wilt disease and severe losses is Fusarium basal rot (FBR). In this study, the combination of Arbuscular Mycorrhizal Fungi (AMF) with Trichoderma harzianum was investigated against FBR. Onion samples were collected from the Ankara–Polatlı region. Among the isolates, isolate S6 was identified as F. oxysporum f. sp. cepae (FOC) using morphological and molecular methods and pathogenicity tests. Different combinations of AMF (Funneliformis mosseae pure strain and the commercial AMF) and T. harzianum were inoculated on susceptible onion cultivars (Seç, Gence, and Şampiyon). The effects of the treatments on FOC biocontrol were studied under growth chamber conditions. The results showed that Şampiyon was the most resistant, while Gence was the most susceptible to basal rot disease. Different colonization rates (8.91–24%), spore densities (16.4–50.4 spore/10 g soil), and the extent to which a plant needs mycorrhizal conditions to grow to its maximum potential (i.e., mycorrhizal dependencies—18.3–51.9%) were recorded by treatment. Both single and combined applications of AMF and Trichoderma applications suppressed FOC. Suppressive effects were more pronounced when the F. mosseae pure strain was used alone (when F. mosseae was used, disease severity decreased from 90 to 68%, p < 0.05). The F. mosseae pure strain also showed the best plant growth promotion and phosphorus content release. The results indicate an interesting potential use of F. mosseae and the combination of AMF with T. harzianum in the management of FOC in onions.

Effects of the synergistic treatments of arbuscular mycorrhizal fungi and trehalose on adaptability to salt stress in tomato seedlings.

AMF improve the plant adaptability to salt resistance by increasing mineral absorption and reducing the damage of saline soil. Trehalose plays an important role in plant response to salt damage by regulating osmotic pressure. Together, the use of AMF and trehalose in tomato seedlings proved efficient in regulating host substance synthesis, osmosis, and antioxidant enzymes. These synergistic effects significantly improved seedling adaptability to salt stress by enhancing cell osmotic protection and cell antioxidant capacity, ultimately reducing losses to crops grown on land where salinization has occurred.

The functional division of arbuscular mycorrhizal fungi and earthworm to efficient cooperation on phytoremediation in molybdenum (Mo) contaminated soils

Single phytoremediation has limited capacity to restore soil contaminated with extreme Mo due to its low metal accumulation. Soil organisms can help compensate for this deficiency in Mo-contaminated soils. However, there is limited information available on the integrated roles of different types of soil organisms, particularly the collaboration between soil microorganisms and soil animals, in phytoremediation. The objective of this study is to investigate the effects of a combination of arbuscular mycorrhizal fungi (AMF) and earthworms on the remediation of Mo-contaminated soils by alfalfa (Medicago sativa L.). The results indicated that in the soil-alfalfa system, earthworms effectively drive soil Mo activation, while AMF significantly improve the contribution of the translocation factor to total Mo removal (TMR) in alfalfas (p < 0.05). Meanwhile, compared to individual treatments, the combination of AMF and earthworm enhanced the expression of alfalfa root specific Mo transporter - MOT1 family genes to increase alfalfa uptake Mo (p < 0.05). This alleviated the competition between P/S nutrients and Mo on non-specific Mo transporters-P/S transporters (p < 0.05). Additionally, the proportion of organelle-bound Mo in the root was reduced to decrease Mo toxicity, while the cell wall-bound Mo proportion in the shoot was increased to securely accumulate Mo. The contributions of inoculants to alfalfa TMR followed the order (maximum increases): AMF + E combination (274.68 %) > alone treatments (130 %). Overall, the "functional division and cooperation" between earthworm and AMF are of great importance to the creation of efficient multi-biological systems in phytoremediation.

The physiological responses of celery (Apium graveolens L.) and its ability to accumulate selenium when inoculated with Funneliformis mosseae

Celery (Apium graveolens L.) has a strong capacity to enrich selenium (Se) and is a good system for research on Se enrichment in vegetables. Arbuscular mycorrhizal fungi (AMF) are commonly used plant symbionts that affect plant growth and their effectiveness is plant species specific. However, there is little research on the effects of AMF inoculation on the accumulation and translocation of Se in celery. The treatments in this study included inoculation with AMF (+AMF) and the application of different types and concentrations of exogenous Se. We evaluated the growth, root mycorrhizal colonization, photosynthetic pigment content, ascorbate-glutathione cycle (ASA-GSH cycle), the accumulation and translocation of Se and the combination of AMF + Se compared with an untreated control. The application of low concentrations of Se (≤10 mg kg−1) stimulated celery growth, while high concentrations (>20 mg kg−1) had the opposite effect. The inhibition of celery growth was more severe with Se6+ than Se4+ when applied at the same concentration. The accumulation of Se improved in all the organs of celery as the supply increased. AMF had a significant positive effect on the accumulation and translocation of Se. In addition, +AMF significantly increased the shoot height and root fresh weight of celery and reduced the inhibitory effect of Se on growth. However, +AMF had slight effects on the levels of photosynthetic pigments and the ASA-GSH cycle. +AMF combined with 10 mg kg−1 sodium selenite (Se4+) is an effective way to produce Se-rich celery.

Effect of Arbuscular Mycorrhizal Fungi on Lowland Rice Growth and Yield (Oryza sativa L.) under Different Farming Practices

In this study, a field experiment was conducted to evaluate the growth and yield responses of Sri Lankan lowland rice (Oryza sativa L.) with the application of beneficial Arbuscular mycorrhizal fungi (AMF) inoculum and intercropping with highly mycorrhizal-dependent vetiver grass (Chrysopogon zizanioides L.) under two different soil nutrient management systems (NMSs): conventional/chemical (CNMS) and organic (ONMS). The experiment was designed as a split plot with three blocks. Each CNMS and ONMS experiment included an untreated control (T0) and three treatments—AMF inoculation (T1), vetiver intercropping (T2), and the combination of AMF and vetiver (T3). According to the results, the colonization of rice roots with AMF was not affected significantly by the treatments and ranged from 0–15.8%. The effect was very low or absent in the early stage and then higher in the later stages of the rice plant. Furthermore, plant growth was not significantly different between the two NMSs, although grain yield was significantly higher (p &lt; 0.05) in ONMS than for the respective controls (T0), with the order T1 (0.45 kg/m2) &gt; T2 (0.42 kg/m2) &gt; T3 (0.41 kg/m2) in CNMS and T2 (0.44 kg/m2) &gt; T1 (0.41 kg/m2) &gt; T3 (0.40 kg/m2), thus suggesting the utilization of AMF and vetiver in a lowland rice farming system is beneficial.

Integrative application of biochar and arbuscular mycorrhizal fungi for enhanced chromium resistance in Medicago sativa

Soil chromium (Cr) contamination has become an environmental problem of global concern. However, the joint effects of combined utilization of biochar and arbuscular mycorrhizal (AM) fungal inoculum, which are considered as two promising remediation strategies of soil heavy metal pollutions, on plant Cr resistance are still poorly understood. In this study, a two-factor pot experiment was conducted to investigate how biochar and AM fungus Rhizophagus irregularis regulate Medicago sativa growth, physiological trait, nutrient and Cr uptake, relevant gene expressions, soil properties, and Cr speciation, independently or synergistically. The results showed that biochar notably decreased AM colonization, while biochar and AM fungus could simultaneously increase plant dry biomass. The greatest growth promotion was observed in mycorrhizal shoots at the highest biochar level (50 g kg−1 soil) by 91 times. Both biochar application and AM fungal inoculation enhanced plant photosynthesis and P nutrition, but the promoting effects of AM fungus on them were significantly greater than that of biochar. In addition, the combined application of biochar and AM fungus dramatically reduced shoot and root Cr concentrations by up to 92 % and 78 %, respectively, compared to the non-amended treatment. Meanwhile, down-regulated expressions were observed for metal chelating-related genes. Furthermore, Cr translocation from roots to shoots was reduced by both two soil amendments. Transcriptional levels of genes involved in reactive oxygen species and proline metabolisms were also regulated by biochar application and AM fungal colonization, leading to alleviation of Cr phytotoxicity. Furthermore, AM fungal inoculation slightly elevated soil pH but decreased plant-available soil P, which was, by contrast, lifted by biochar addition. The combined application reduced soil acid-extractable Cr concentration by 40 %. This study provides new insights into comprehensively understanding of the mechanisms of biochar and AM fungi combination on improving plant Cr tolerance.

Arbuscular mycorrhizae increase but vermicompost decrease the sun protection factor (SPF) in leaves of Hymenaea martiana Hayne seedlings

This study aimed to select the most efficient combination of arbuscular mycorrhizal fungi (AMF) and substrate to increase the photoprotective and in vitro antioxidant activities in Hymenaea martiana Hayne leaves. Hymenaea martiana seedlings were grown in soil with or without 10% vermicompost and inoculated with three AMF species: Acaulospora longula, Gigaspora albida, and Claroideoglomus etunicatum. Seedlings grown in soil without vermicompost or AMF inoculation served as controls. After 148 days of growth in a greenhouse, the photoprotective and antioxidant activities, and the production of some phenolics in the leaves were evaluated. Vermicompost supplementation reduced the photoprotective and antioxidant effects in extracts compared to the control. However regardless of the vermicompost treatment, mycorrhizal colonization resulted in a 40% increase in photoprotective activity compared to control; this enhancement was correlated with the increased concentration of proanthocyanidins in mycorrhizal plants. AMF inoculation improves the quality of H. martiana phytomass, dispensing the application of vermicompost in the cultivation substrate. This is the first report on the potential of AMF and vermicompost to increase the sun protection factor in H. martiana leaves.

Effect of Organic Amendments and Arbuscular Mycorrhizal Fungi on Plant Growth, Yield And Quality of Strawberry

An experiment was conducted at the research field and the laboratory of the Department of Horticulture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur-1706, Bangladesh from October 2018 to March 2019 to investigate the effect of organic amendments and arbuscular mycorrhizal fungi (AMF) on growth, yield and quality of strawberry var. BARI Strawberry-2. The experiment was laid out in RCBD design with three replications taking into eight treatments including control viz., T1: vermicompost (324 g/pot), T2: biochar (324 g/pot), T3: AMF (324g/pot), T4: vermicompost (162 g/pot) + biochar (162 g/pot), T5: biochar (162 g/pot) + AMF (162 g/pot), T6: vermicompost (162 g/pot) + AMF (162 g/pot), T7: vermicompost (108 g/pot) + biochar (108 g/pot) + AMF (108 g/pot) and T8: control (no manure or AMF). Results of the study revealed that the highest plant height (18.40 cm), number of leaves/plant (37.00), leaf area (578.60 cm2), root length (24.50 cm), fresh and dry weight of root (30.00 g and 12.5 g) and shoot (131 g and 41.00 g), number of flowers (32.67/plant) and fruits (22.33/plant), single fruit weight (21.60 g) and yield/plant (401.99 g) were recorded in T6 treatment which was significantly superior to all other treatments. Among the fruit nutrient and mineral contents, ascorbic acid (36.20 mg/100 g), total sugar (9.10 g/100 g), Ca (11.87 mg/100 g), Mg (36.67 mg/100 g) and K (73.33 mg/100 g) were also measured maximum in T6 treatment. On the other hand, TSS (8.49 %) and water percentage in fruit (66.95 %) were found significantly higher in T7 and T4 treatments, respectively while the lowest was estimated in the control. A significant influence of T6 treatment [vermicompost (162 g/pot) + AMF (162 g/pot)] on growth, yield and qualitative characters was observed. Therefore, vermicompost and AMF combination has reflected a positive impact on good quality strawberry production. However, it needs to be investigated under the open field condition before conferring recommendation to the end users. Ann. Bangladesh Agric. (2022) 26 (2) : 71-82

Enhancing Vicia faba’s immunity against Rhizoctonia solani root rot diseases by arbuscular mycorrhizal fungi and nano chitosan

BackgroundThe spreading of root rot disease of faba bean plant (Vichia faba L, VF) in Egypt is still of great challenge faced researchers since VF is an important legume in Egypt, because their seeds are used for human feeding. Fungicides are used for treatment of either seeds or soil; unfortunately they cause environmental pollution. Therefore, there is a need to continue research to find out safe natural solutions. In this regard, Arbuscular mycorrhizal fungi (AMF) and chitosan (micro or nanoform) were used as an inhibitory product against Rhizoctonia solani OM918223 (R.solani) either singly or in combinations.ResultsThe results employed herein have exhibited that R.solani caused root rot disease of VF plants in more than 80% of the plants under investigation. Chitosan nanoparticles (Chitosan NPs) were prepared by ionic gelatin method and characterized by using dynamic light scattering (DLS), transmission electron microscopy (TEM) imaging and Fourier transform infra-red (FTIR). Chitosan NPs are spherical with a diameter of 78.5 nm and exhibited the presence of different functional groups. The inhibitory natural products against R.solani were arranged according to their ability to inhibit the pathogen used in the following descending manner; combination of AMF with Chitosan NPs, AMF with micro chitosan and single AMF, respectively. Where, Chitosan NPs showed a potent influence on R.solani pathogen and reduced the pre-and post-emergence of R. solani. In addition, Chitosan NPs reduced Disease Incidence (DI %) and Disease Severity (DS %) of root rot disease and are widely functional through mixing with AMF by about 88% and 89%. Further, Chitosan NPs and micro chitosan were proved to increase the growth parameters of VF plants such as nutritional status (mineral, soluble sugar, and pigment content), and defense mechanisms including total phenol, peroxidase, and polyphenol oxidase in mycorrhizal plants more than non-mycorrhizal one either in infected or healthy plants. Moreover, activity of AMF as an inhibitory against R.solani and improvement natural agent for VF growth parameters was enhanced through its fusing with Chitosan NPs.ConclusionsThe use of AMF and Chitosan NPs increased faba bean plant resistance against the infection of root rot R. solani, with both prevention and cure together. Therefore, this research opens the door to choose natural and environmental friendly treatments with different mechanisms of plant resistance to disease.

Organic Materials and AMF Addition Promote Growth of Taxodium ‘zhongshanshan’ by Improving Soil Structure

Soil salinization is considered a type of global-scale soil degradation, whereby excessive salinity severely diminishes soil health, which is primarily manifested through disrupted soil structures and reduced fertility. Furthermore, plant growth capacity is inhibited, and productivity is diminished. Consequently, the improvement of saline soils is regarded as a particularly important aspect of enhancing land production. To elucidate the roles of organic amendments and mycorrhizal fungi in the improvement of saline soils, seven treatments were set up, including biochar alone (B), straw alone (S), arbuscular mycorrhizal fungi alone (A), biochar in combination with arbuscular mycorrhizal fungi (BA), straw in combination with arbuscular mycorrhizal fungi (SA), and a control (CK). The results revealed that the seedling height growth rate under the BA treatment was significantly higher than that of the CK by 31.66%. The capillary porosity of the soil under the addition of BA was significantly higher than the CK by 3.17% in the 0–20 cm soil layer. The BA treatment reduced the fractal dimension of soil aggregates considerably by 19.06% in the 0–20 cm soil layer, and 13.71% in the 40–60 cm soil layer in contrast to the CK, respectively. In addition, the positive effects of the BA treatment were significant in the 20–40 cm soil layer. Overall, the application of biochar alone promoted the water stability of soil aggregates. The combination of arbuscular mycorrhizal fungi and biochar promoted plant growth, improved soil pore structures, promoted agglomerate water stability, and led to improved microbial activities. The results showed that organic amendments applied in conjunction with AMF improved the environment of salinized soil, which is a key factor in the promotion of plant growth and the long-term stability of soil health. This study provides a key technical basis for remediation of salinized soil.

Can arbuscular mycorrhizal fungi and rhizobacteria facilitate 33P uptake in maize plants under water stress?

Arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) are able to provide key ecosystem services, protecting plants against biotic and abiotic stresses. Here, we hypothesized that a combination of AMF (Rhizophagus clarus) and PGPR (Bacillus sp.) could enhance 33P uptake in maize plants under soil water stress. A microcosm experiment using mesh exclusion and a radiolabeled phosphorus tracer (33P) was installed using three types of inoculation: i) only AMF, ii) only PGPR, and iii) a consortium of AMF and PGPR, alongside a control treatment without inoculation. For all treatments, a gradient of three water-holding capacities (WHC) was considered i) 30% (severe drought), ii) 50% (moderate drought), and iii) 80% (optimal condition, no water stress). In severe drought conditions, AMF root colonization of dual-inoculated plants was significantly lower compared to individual inoculation of the AMF, whilst 33P uptake by dual-inoculated plants or plants inoculated with bacteria was 2.4-fold greater than the uninoculated treatment. Under moderate drought conditions the use of AMF promoted the highest 33P uptake by plants, increasing it by 2.1-fold, when compared to the uninoculated treatment. Without drought stress, AMF showed the lowest 33P uptake and, overall, plant P acquisition was lower for all inoculation types when compared to the severe and moderate drought treatments. The total shoot P content was modulated by the water-holding capacity and inoculation type, with the lowest values observed under severe drought and the highest values under moderate drought. The highest soil electrical conductivity (EC) values were found under severe drought in AMF-inoculated plants and the lowest EC for no drought in single or dual-inoculated plants. Furthermore, water-holding capacity influenced the total soil bacterial and mycorrhizal abundance over time, with the highest abundances being found under severe and moderate drought. This study demonstrates that the positive influence of microbial inoculation on 33P uptake by plants varied with soil water gradient. Furthermore, under severe stress conditions, AMF invested more in the production of hyphae, vesicles and spore production, indicating a significant carbon drain from the host plant as evidenced by the lack of translation of increased 33P uptake into biomass. Therefore, under severe drought the use of bacteria or dual-inoculation seems to be more effective than individual AMF inoculation in terms of 33P uptake by plants, while under moderate drought, the use of AMF stood out.

Arbuscular mycorrhiza and plant growth promoting endophytes facilitates accumulation of saponin under moderate drought stress

ObjectiveParis polyphylla var. yunnanensis, one of the important medicinal plant resources in Yunnan, China, usually takes 6–8 years to be harvested. Therefore, it is urgent to find a method that can not only shorten its growth years, but also improve its quality. In this study, we examined the effects of a combination treatment of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting endophytes (PGPE) and drought stress on the accumulation of saponins in it. MethodsP. polyphylla var. yunnanensis was infected with a mixture of AMF and PGPE under drought stress. The content of saponins, as well as morphological, physiological, and biochemical indicators, were all measured. The UGTs gene related to saponin synthesis was obtained from transcriptome data by homologous comparison, which were used for RT-PCR and phylogenetic analysis. ResultsRegardless of water, AMF treatment could infect the roots of P. polyphylla var. yunnanensis, however double inoculation with AMF and PGPE (AMF + PGPE) would reduce the infection rate of AMF. Plant height, aboveground and underground fresh weight did not differ significantly between the single inoculation AMF and the double inoculation treatment under different water conditions, but the inoculation treatment significantly increased the plant height of P. polyphylla var. yunnanensis compared to the non-inoculation treatment. Single inoculation with AMF considerably increased the net photosynthetic rate, stomatal conductance, and transpiration rate of P. polyphylla var. yunnanensis leaves under various water conditions, but double inoculation with AMF + PGPE greatly increased the intercellular CO2 concentration and chlorophyll fluorescence parameter (Fv/Fm). Under diverse water treatments, single inoculation AMF had the highest proline content, whereas double inoculation AMF + PGPE may greatly improve the amount of abscisic acid (ABA) and indoleacetic acid (IAA) compared to normal water under moderate drought. Double inoculation AMF + PGPE treatment improved the proportion of N, P, and K in the rhizome of P. polyphylla var. yunnanensis under various water conditions. Under moderate drought stress, AMF + PGPE significantly enhanced the contents of P. polyphylla var. yunnanensis saponins I, II, VII, and total saponins as compared to normal water circumstances. Farnesyl diphosphate synthase (FPPS), Geranyl pyrophosphate synthase (GPPS), Cycloartenol synthase (CAS), and Squalene epoxidase (SE1) were the genes that were significantly up-regulated at the same time. The amount of saponins was favorably linked with the expression of CAS, GPPS, and SE1. Saponin VI content and glycosyl transferase (UGT) 010922 gene expression were found to be substantially associated, as was saponin II content and UGT010935 gene expression. ConclusionUnder moderate drought, AMF + PGPE was more conducive to the increase of hormone content, nutrient absorption, and total saponin content in P. polyphylla var. yunnanensis, and AMF + PGPE could up regulate the expression of key genes and UGTs genes in one or more steroidal saponin synthesis pathways to varying degrees, thereby stimulating the synthesis and accumulation of steroidal saponins in the rhizome of P. polyphylla var. yunnanensis. The combination of AMF and PGPE inoculation, as well as adequate soil drought, reduced the buildup of saponins in P. polyphylla var. yunnanensis and increased its quality.

Synergistic combination of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria modulates morpho-physiological characteristics and soil structure in Nitraria tangutorum bobr. Under saline soil conditions

Nitraria tangutorum Bobr., a typical xero-halophyte, can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity. However, global climate change and unreasonable human activity have exacerbated salinization in arid and semi-arid regions, which in turn has led to the growth inhibition of halophytes, including N. tangutorum. Arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) have the potential to improve the salt tolerance of plants and their adaptation to saline soil environments. In this study, the effects of single and combined inoculations of AMF (Glomus mosseae) and PGPR (Bacillus amyloliquefaciens FZB42) on N. tangutorum were evaluated in severe saline soil conditions. The results indicate that AMF and PGPR alone may not adapt well to the real soil environment, and cannot ensure the effect of either growth promotion or salt-tolerance induction on N. tangutorum seedlings. However, the combination of AMF and PGPR significantly promoted mycorrhizal colonization, increased biomass accumulation, improved morphological development, enhanced photosynthetic performance, stomatal adjustment ability, and the exchange of water and gas. Co-inoculation also significantly counteracted the adverse effect of salinity on the soil structure of N. tangutorum seedlings. It is concluded that the effectiveness of microbial inoculation on the salt tolerance of N. tangutorum seedlings depends on the functional compatibility between plants and microorganisms as well as the specific combinations of AMF and PGPR.

Promoting growth and production of sunchoke (Helianthus tuberosus) by co-inoculation with phosphate solubilizing bacteria and arbuscular mycorrhizal fungi under drought.

Due to different functions of phosphate solubilizing bacteria (PSB) and arbuscular mycorrhizal fungi (AMF), their potential synergistic effects on enhancing plant growth and yield are worth investigating, especially under adverse conditions. This work focused on the isolation of PSB and characterization for their plant growth promoting properties under drought. The most efficient P solubilizing bacterium was isolated and identified as Burkholderia vietnamiensis strain KKUT8-1. Then, a factorial experiment on the performance of sunchoke (Helianthus tuberosus) was set up with four factors, viz., PSB (presence or absence of KKUT8-1), AMF (presence or absence of Rhizophagus aggregatus), rock phosphate (RP; added or not) and moisture (well-watered (WW) or drought (DS) conditions). Sunchoke performance was enhanced by the presence of AMF, whereas addition of PSB had a positive effect on SPAD values and inulin concentration. Drought reduced plant performance, while addition of RP reduced photosynthetic rate. There was little evidence for synergistic effects between PSB and AMF, except for SPAD values and inulin concentration. Plants that were co-inoculated with AMF and PSB had highest SPAD value, shoot diameter, leaf area, leaf number, chlorophyll concentration, plant biomass, tuber production, root growth and total soluble sugar concentration. Co-inoculated plants also had increased plant water status, reduced electrolyte leakage, and reduced malondialdehyde and proline concentration. Strain KKUT8-1 is the first strain of B. vietnamiensis capable of promoting growth and yield of sunchoke. Enhanced production of sunchoke by a combination of AMF and PSB was much better than the application of RP. Our finding offers an opportunity to develop combinations of biological inoculants for increasing the growth and production of sunchoke under drought in the future.

THE EFFECTIVENESS OF MULTIPLE INOCULATION OF BIODIVERSITY IN IMPROVING SOIL BIOLOGICAL PROPERTIES AND RESULTS OF TWO GOGO RICE VARIETIES IN COASTAL AREA

This study aims to obtain a combination of biological fertilizers and upland rice varieties that can improve soil biological properties and increase upland rice production in coastal areas. This research was conducted from September to December 2019, in Beringin Raya Village, Muara Bangkahulu District, Bengkulu City. Soil and plant analysis were carried out at the Soil Science Laboratory, Faculty of Agriculture, Bengkulu University. This study used a Completely Randomized Block Design (RAKL). The first factor tested was upland rice varieties consisting of Inpago 10 and Serantan. Furthermore, the second factor is the type of biological fertilizer which consists of control, a combination of P solubilizing bacteria, K solubilizing bacteria, and N2 fixing bacteria, as well as a combination of arbuscular mycorrhizal fungi, K solubilizing bacteria, and N2 fixing bacteria. Each treatment combination was repeated 4 times so that there were 24 experimental units. Each experiment consisted of 50 plants so that the total plant population was 50 x 24 = 1,200 plants. The results showed that the combination of double inoculants of biological fertilizers BPF + BPK + BPN and rice variety Inpago 10 resulted in the highest population of potassium solubilizing bacteria, plant dry weight and weight of pithy grain per clump. Double inoculants of BPF + BPK + BPN biofertilizers resulted in the highest population of potassium solubilizing bacteria, the heaviest plant dry weight and weight of pithy grain per clump. Inpago 10 variety also had a higher population of potassium solubilizing bacteria, and better growth and yield components of rice compared to the serantan variety.

The combination of vermicompost and arbuscular mycorrhizal fungi improves the physiological properties and chemical composition of Opuntia ficus-indica under semi-arid conditions in the field

Drought is one of the major threats to food security in arid and semi-arid regions. Therefore, significant changes in agricultural production systems will be required to meet the challenges of food security while addressing water scarcity. Prickly pear is a drought tolerant plant, as well as a source of sustainable food and feed. Nonetheless, in dry conditions, its growth and performance are restricted. The aim of this study was to evaluate the effect of arbuscular mycorrhizal fungi (AMF), vermicompost (Vc) or the combination of AMF + Vc on yield, growth and physio-chemical parameters of cactus grown under field drought conditions. Two irrigation regimes were applied, non-irrigated (grown under rainfed conditions) and irrigated plants (8 mm of water per week). After eight months of cultivation, the finding demonstrated that drought reduced growth, physiological and biochemical parameters of cactus. However, the application of biostimulants, especially Vc and AMF + Vc, can mitigate the negative effect of drought by increasing cladode dry weight (93% and 109%), total chlorophyll (78% and 75%), total phenolic content (83% and 81%). Those treatments are also efficient in enhancing activities of enzymatic and non enzymatic antioxidants in cactus cladodes and fruits. These results suggest that the use of these biostimulants can mitigate the challenges associated with drought, by improving the physiological and biochemical responses of cactus.

Mycorrhization of strawberry plantlets potentiates the synthesis of phytochemicals during ex vitro acclimatization

Ex vitro strawberry plantlets from micropropagation and coinoculated with arbuscular mycorrhizal fungi (AMF) and biochar can provide beneficial health effects. In the present study, we evaluated the effects of different proportions of biochar in the presence and absence of AMF on the production of secondary metabolites in the leaves and roots of strawberry plantlets during ex vitro acclimatization. Additionally, the enzymatic activity of the substrate enriched with AMF and biochar was analyzed. The experiment consisted of the control (absence of the mycorrhizal community) and four biochar proportions (0, 3, 6, and 9% of the volume of the container) coinoculated with AMF. Plantlets produced on substrates enriched with AMF showed higher levels of polyphenols, flavonoids, phenolic acids, and tannins in the tissues analyzed than control plantlets. The combination of AMF and 9% biochar increased the content of total flavonoids in the leaves of strawberry plantlets and increased the activity of phosphatase. The substrate with up to 6% biochar and mycorrhizae showed increased β-glucosidase activity. In conclusion, mycorrhizae are excellent tools to improve the phytochemical quality of strawberry plantlets acclimatized ex vitro. The association between host plants, mycorrhizal symbionts, and bioactivators of these fungi potentiates properties beneficial to health, which can be exploited efficiently in sustainable agriculture.

Yerfıstığında (Arachis hypogea L.) Mikoriza, Demir ve Çinko Uygulamalarının Verim ve Tarımsal Özellikler Üzerine Etkisi

The exogenous applications of arbuscular mycorrhizal fungi (AMF), iron and zinc have the potential to increase yield in peanut. The objective of this study was to evaluate the effects of AMF, Fe and Zn combinations on yield and yield components in peanut. Seed coating with AMF and foliar sprays of Fe and Zn were arranged in split-split block design with four replications under farmer’ condition in 2020. The highest values for pod number per plant, pod and kernel yield (kg ha-1) and 100 seed weight were recorded in parcels where AMF, Fe and Zn were applied together. The combination of AMF, Fe and Zn favorable affected maturity date and harvest index. It was highlighted that AMF, Fe and Zn combinations could be used successfully to improve the yield and in peanut cultivation.