Glomus Etunicatum Research Articles

Arbuscular Mycorrhizal Fungal Interacted with Biochar and Enhanced Phosphate-Solubilizing Microorganism Abundance and Phosphorus Uptake in Maize

In agricultural production, it is crucial to increase the availability of phosphorus (P) in cultivated soil to solve the P limitation. Arbuscular mycorrhizal fungi (AMF) have been proven to promote crop nutrient absorption effectively, while biochar can lead to improvements in soil properties. However, the possible synergistic effect of AMF and biochar on P uptake by crops as well as its underlying mechanisms are unclear. In this study, we conducted a pot experiment to explore the effects of biochar and AMF (Glomus etunicatum) on the community of rhizospheric phosphate-solubilizing microorganisms (PSMs) of maize (Zea mays L. Xianyu-335) using metagenomic methods. The experiment used 0 mg P2O5 g·kg−1 soil (P0) and 30 mg P2O5 g·kg−1 soil (P30) application rates. Each P application rate included 0 (NC), 20 g·kg−1 biochar (BC) addition, inoculation AMF, and without AMF treatments (NM) for a total of eight treatments. During the experiment, both the P uptake and the biomass of maize were measured. The study found that the combination of AMF and biochar significantly increased the mycorrhizal colonization rate of maize roots, regardless of P application level. It was observed that the P uptake by maize was significantly increased when exposed to a combination of AMF and biochar. The increase in P uptake in P0 treatments was 67% higher than the sum of the effects of biochar and AMF inoculation alone. The increase was only 35% higher in P30 treatments, demonstrating a substantially higher interactive effect under P0 than under P30 conditions. The AM-BC treatments significantly increased the abundance of Streptomyces, Bacillus, and Pseudomonas, genera that are known to contain PSMs. In addition, the abundance of genes related to P-cycling (gcd, phoD, and ugpQ) in PSMs increased significantly by 1.5–1.8 times in AM-BC treatments compared with NM-BC and AM-NC treatments under P0 conditions. This increase was significantly and positively correlated with the P uptake. Overall, the results suggest that biochar can help AMF colonize the roots, increasing the functional roles of PSMs in the rhizosphere, which in turn promotes P uptake and biomass in maize. This study provides a new way to improve P-use efficiency and reduce the need for P-fertilizer application in agricultural production.

Arbuscular mycorrhizal fungi improve the competitive advantage of a native plant relative to a congeneric invasive plant in growth and nutrition.

Plant invasions severely threaten natural ecosystems, and invasive plants often outcompete native plants across various ecosystems. Arbuscular mycorrhizal (AM) fungi, serving as beneficial microorganisms for host plants, can greatly influence the competitive outcomes of invasive plants against native plants. However, it remains unclear how AM fungi alter the competitive balance between native and invasive species. A competitive experiment was conducted using an invasive Eupatorium adenophorum paired with a native congener Eupatorium lindleyanum. Specifically, both species were inoculated with (M+) or without (M-) the fungus Glomus etunicatum under intraspecific (Intra-) and interspecific (Inter-) competition. Plant traits were measured and analyzed regarding the growth and nutrition of both species. The results exhibited that the AM fungus significantly increased the height, diameter, biomass, C, N, and P acquisition of both the invasive E. adenophorum and the native E. lindleyanum. The root mycorrhizal colonization and the mycorrhizal dependency of native E. lindleyanum were greater than those of invasive E. adenophorum. Under M+, the Inter-competition inhibited the growth and nutrition of invasive E. adenophorum compared to the Intra- competition. Further, native E. lindleyanum exhibited higher competitiveness than invasive E. adenophorum in growth and nutrition. Meanwhile, the AM fungus significantly improved the competitiveness of native E. lindleyanum over invasive E. adenophorum. In conclusion, AM fungus improved the competitive advantage of native E. lindleyanum over invasive E. adenophorum in growth and nutrition, potentially contributing to native species competitively resisting the invasion of exotic species. These findings emphasize the importance of AM fungi in helping native plants resist the invasion of exotic plants and further contribute to understanding plant invasion prevention mechanisms.

Effect of inoculation with arbuscular mycorrhizal fungi on the energy metabolism of selenite-rich amaranth.

A series of pot trials were undertaken to examine the impact of four arbuscular mycorrhizal fungi (AMF), namely Glomus mosseae (G.m), Glomus etunicatum (G.e), Corymbiglomus tortuosum (C.t), and the combined application of Glomus etunicatum and Corymbiglomus tortuosum (G.e + C.t), on the energy metabolism of amaranth plants grown in soil enriched with selenite at a concentration of 0.5 mg kg-1 . The inoculation of four AMFs resulted in an increase in both amaranth biomass and selenium (Se) content in leaves. The activities of phosphoglucose isomerase (PGI) and glucose-6-phosphate dehydrogenase + 6-phosphogluconate dehydrogenase were observed to decrease when AMFs were inoculated, as compared with the absence of AMF inoculation. The inoculation with G.m, C.t, and G.e + C.t resulted in an increase in succinate dehydrogenase activity; however, the inoculation with G.m, G.e, and G.e + C.t led to an increase in ascorbate oxidase activity. Furthermore, the inoculation of all four AMFs resulted in an increase in cytochrome c oxidase activity and the concentrations of oxidized coenzyme I (NAD) and reduced coenzyme I (NADH). The polyphenol oxidase activity of amaranth plants increased when inoculated with G.m and G.e, whereas it decreased when inoculated with C.t and G.e + C.t. Furthermore, the application of all four AMF treatments resulted in a reduction in adenosine triphosphate (ATP) levels and energy charge. It was worth mentioning that there was a clear inverse relationship between the energy charge and the biomass, Se concentration in the leaves. The findings presented in this research indicated that AMF may have an impact on energy metabolism and ultimately the biomass of amaranth by influencing the uptake of Se.

Arbuscular mycorrhizal fungi communities and promoting the growth of alfalfa in saline ecosystems of northern China.

Arbuscular mycorrhizal fungi (AMF) are universally distributed in soils, including saline soils, and can form mycorrhizal symbiosis with the vast majority of higher plants. This symbiosis can reduce soil salinity and influence plant growth and development by improving nutrient uptake, increasing plant antioxidant enzyme activity, and regulating hormone levels. In this study, rhizosphere soil from eight plants in the Songnen saline-alkaline grassland was used to isolate, characterize, and screen the indigenous advantageous AMF. The promoting effect of AMF on alfalfa (Medicago sativa L.) under salt treatment was also investigated. The findings showed that 40 species of AMF in six genera were identified by high-throughput sequencing. Glomus mosseae (G.m) and Glomus etunicatum (G.e) are the dominant species in saline ecosystems of northern China. Alfalfa inoculated with Glomus mosseae and Glomus etunicatum under different salt concentrations could be infested and form a symbiotic system. The mycorrhizal colonization rate and mycorrhizal dependence of G.m inoculation were significantly higher than those of G.e inoculation. With increasing salt concentration, inoculation increased alfalfa plant height, fresh weight, chlorophyll content, proline (Pro), soluble sugar (SS), soluble protein (SP), peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity while decreasing the malondialdehyde (MDA) content and superoxide anion production rate. The results highlight that inoculation with G.m and G.e effectively alleviated salinity stress, with G.m inoculation having a significant influence on salt resistance in alfalfa. AMF might play a key role in alfalfa growth and survival under harsh salt conditions.

KETERGANTUNGAN SEMAI JOHAR (Cassia siamea LAMK) TERHADAP FUNGI MIKORIZA ARBUSKULA PADA MEDIA TAILING TAMBANG EMAS

Tailings are the wastes resulting from mining activities in the amalgamation of mine ore from the ground, with extreme characteristics such as a sand-dominated texture, high Pb heavy metal content, very low availability of carbon and macro nutrients. Consequently, the plants may not able to grow well in the tailings. The application of Arbuscular Mycorrhyza Fungi (AMF) is expected to increase the ability of forest plant seedlings to grow and develop in tailings media. The research was carried out in a greenhouse using johar (Cassia siamea Lamk) seedlings which were inoculated with AMF inoculum: Glomus manihotis, Glomus etunicatum, and mix inoculan (mycofer), and planted in tailings media collected from Pongkor gold mine for 8 weeks. Johar seedlings were able to grow in tailings media and AMF colonization to the seedlings was observed. The compatibility of multi-species inoculum, mycofer, is higher than single AMF inoculum. The height, diameter and biomass growth of johar seedlings in tailings media significantly (p<0.05) increased with AMF inoculation. Johar seedlings have a high dependence on AMF, on tailings media, undicated by value of MIE > 50%, suggesting that the AMF application to johar is very necessary for revegetation activities in tailings media.

Soil patch heterogeneity improves plant productivity and nutrients regulated by arbuscular mycorrhizal fungi

AbstractThe interlacing and mosaic distribution of karst soil and rock result in the high spatial heterogeneity of the natural karst habitat. Karst plants are suffered from spatially heterogeneous microhabitats with different‐sized patches. Arbuscular mycorrhizal (AM) fungi are crucial in regulating plant productivity and nutrients in heterogeneous karst environments. However, how spatial patch heterogeneity influences plant productivity and nutrient utilization by AM fungi regulation in karst soil remains unclear. A simulated heterogeneity experiment regarding soil grid patches was conducted by planting Bidens pilosa into a microcosm of a square device. Experimental treatments included the mycorrhizal fungus treatments inoculation with (M+) or non‐inoculation with (M−) Glomus etunicatum fungus, and the spatial heterogeneity treatments involved homogeneous patches (HO), heterogeneity‐small patches (HS), and heterogeneity‐large patches (HL). The growth and nutritional traits of plants were analyzed. The results showed that AM fungus promoted the productivity and nutrient uptake of B. pilosa by substantial increases in biomass, nitrogen (N) accumulation, phosphorus (P) accumulation, and N/P ratio. The spatial heterogeneity promoted the biomass and N and P accumulations of B. pilosa when inoculating with AM fungus. The mycorrhizal colonization rate and hyphae length were greater in HS than in HO and HL under the M+ treatment, with a greater response ratio of biomass, N and P under HS conditions. These indicated that the heterogeneous small patches had a greater promotion of the biomass production and nutrients of B. pilosa with inoculation of AM fungus because extensive fungal hyphae can acquire soil resources in more distant patches outside the root zone with more economical metabolic costs compared to roots. We thus conclude that patch heterogeneity contributes to plant productivity and nutrient utilization regulated by AM fungi in karst soil, and the broader nutrient capture induced by extraradical hyphae of AM fungi may be an adaptive mechanism for karst plants to cope with heterogeneous environmental conditions.

Enhancing alfalfa photosynthetic performance through arbuscular mycorrhizal fungi inoculation across varied phosphorus application levels

This study evaluated the effects of arbuscular mycorrhizal fungi inoculation on the growth and photosynthetic performance of alfalfa under different phosphorus application levels. This experiment adopts two-factors completely random design, and sets four levels of fungi application: single inoculation with Funneliformis mosseae (Fm, T1), single inoculation with Glomus etunicatum (Ge, T2) and mixed inoculation with Funneliformis mosseae × Glomus etunicatum (Fm×Ge, T3) and treatment uninfected fungus (CK, T0). Four phosphorus application levels were set under the fungi application level: P2O5 0 (P0), 50 (P1), 100 (P2) and 150 (P3) mg·kg-1. There were 16 treatments for fungus phosphorus interaction. The strain was placed 5 cm below the surface of the flowerpot soil, and the phosphate fertilizer was dissolved in water and applied at one time. The results showed that the intercellular CO2 concentration (Ci) of alfalfa decreased at first and then increased with the increase of phosphorus application, except for light use efficiency (LUE) and leaf instantaneous water use efficiency (WUE), other indicators showed the opposite trend. The effect of mixed inoculation (T3) was significantly better than that of non-inoculation (T0) (p < 0.05). Pearson correlation analysis showed that Ci was significantly negatively correlated with alfalfa leaf transpiration rate (Tr) and WUE (p < 0.05), and was extremely significantly negatively correlated with other indicators (p < 0.01). The other indexes were positively correlated (p < 0.05). This may be mainly because the factors affecting plant photosynthesis are non-stomatal factors. Through the comprehensive analysis of membership function, the indexes of alfalfa under different treatments were comprehensively ranked, and the top three were: T3P2>T3P1>T1P2. Therefore, when the phosphorus treatment was 100 mg·kg-1, the mixed inoculation of Funneliformis mosseae and Glomus etunicatum had the best effect, which was conducive to improving the photosynthetic efficiency of alfalfa, increasing the dry matter yield, and improving the economic benefits of local alfalfa in Xinjiang. In future studies, the anatomical structure and photosynthetic performance of alfalfa leaves and stems should be combined to clarify the synergistic mechanism of the anatomical structure and photosynthetic performance of alfalfa.

The Effect of Mycorrhiza Applications on Growth and Yield in Some Strawberry Cultivars under Calcareous Soil Conditions

This study was conducted in the research and practices of greenhouses at the University of Selçuk, Faculty of Agriculture and Horticulture Department. The effects of three different mycorrhiza species and combinations of strawberry plants on plant growth and nutrition were investigated in three different strawberries cultivars. According to the results, it was determined that Glomus chlorodum mycorrhiza alone and in combination increased stem fresh and root fresh weights, leaf relative water content, number of stems, and number of leaves compared to control plants. However, no significant changes could be obtained with mycorrhizal applications on membrane permeability and chlorophyll values in all strawberry varieties used. Nutrient analysis of nitrogen, magnesium, iron, manganese, and boron in the leaves of the application of mycorrhiza with significant increases has been achieved. Glomus etunicatum + Glomus chlorodum and Glomus deserticola + Glomus etunicatum applications had the best results. As a result of this study, it can be suggested that Glomus etunicatum and Glomus chlorodum can be used to promote plant growth in strawberry calcareous soil conditions.

APLIKASI PUPUK HAYATI MIKORIZA DALAM MENINGKATKAN FASE PERTUMBUHAN VEGETATIF DAN GENERATIF KACANG TANAH (Arachis hypogea L.)

Peanut has long been cultivated in Indonesia and is generally grown on dry land. The continuous use of inorganic fertilizers can have a negative impact on the soil, so there is a need for environmentally friendly fertilizers such as biological fertilizers. This study aimed to elucidate the effect of mycorrhiza biofertilizer on the vegetative and generative growth of peanuts. The study was conducted in the experimental field of Cikabayan IPB with a three-factor Completely Randomized Design. The treatments tested were 1) control, 2) 100% NPK fertilizer, 3) 100% organic fertilizer, 4) 100% organic fertilizer + NPK, 5) 5 g mycorrhizae, 6) 100% NPK + mycorrhizae 5 g, 7) 100% organic fertilizer + mycorrhiza 5 g, and 8) organic fertilizer + NPK 100% + mycorrhiza 5 g. Parameters observed included plant height, number of primary branches, number of pods, pod weight, colonization or root infection, number and types of spores. The results showed that the application of NPK fertilizer + organic fertilizer + mycorrhizae 5 g could increase vegetative and generative growth in peanut plants. The treatment of NPK+ organic fertilizer + mycorrhizae 5 g (AOM) had a very high percentage of infection, which was 86.67%. The AOM treatment had a high number of spores, which was 32 spores and 3 types of spores were successfully associated, namely Acaulospora sp1, Acaulospora sp 2 and Glomus etunicatum.

The interspecific competition of tree plants in the presence of AM fungi and litter facilitates root morphological development and nutrition when compared with intraspecific competition.

Arbuscular mycorrhizal (AM) fungi can affect plant growth by regulating competition. Nutrient-deficient karst habitats contain abundant plants that compete for nutrients through interspecific or intraspecific competition, involving the nutritional transformation of litter decomposition. However, how plant competition in the presence of AM fungi and litter affects root development and nutrition remains unclear. A potted experiment was conducted, including AM fungus treatment with or without Glomus etunicatum, the competition treatment concerning intraspecific or interspecific competition through planting Broussonetia papyrifera and Carpinus pubescens seedlings, and the litter treatment with or without the mixture of B. papyrifera and C. pubescens litter leaves. The root morphological traits were analyzed, and nitrogen (N), phosphorus (P), and potassium (K) were measured. The results showed that AM fungus differently affected the root morphological development and nutrition of both competitive plants, significantly promoting B. papyrifera roots in the increase of dry weight, length, volume, surface area, tips, and branches as well as N, P, and K acquisitions regardless of litter addition. However, there was no apparent influence for C. pubescens roots, except for the diameter in the interspecific competition with litter. The root dry weight, length, volume, surface area, and tips of B. papyrifera under two competitive styles were significantly greater than C. pubescens regulated by AM fungus, presenting significant species differences. The responses of the relative competition intensity (RCI) on root morphological and nutritional traits indicated that AM fungus and litter both asymmetrically alleviated more competitive pressure for B. papyrifera than C. pubescens, and the interspecific competition facilitated more root morphological development and nutrition utilization by endowing B. papyrifera root superiority relative to C. pubescens compared with the intraspecific competition. In conclusion, interspecific competition is more beneficial for plant root development and nutrition than intraspecific competition in the presence of AM fungus and litter via asymmetrically alleviating competitive pressure for different plants.

Effects of AMF inoculation on the eco-physiological characteristics of Imperata cylindrica under differing soil nitrogen conditions.

Arbuscular mycorrhizal fungi (AMF) play a key role in terrestrial ecosystems, while the ecological restoration application of AMF in mining areas has been progressively gaining attention. This study simulated a low nitrogen (N) environment in copper tailings mining soil to explore inoculative effects of four AMF species on the eco-physiological characteristics of Imperata cylindrica, and provided plant-microbial symbiote with excellent resistance to copper tailings. Results show that N, soil type, AMF species, and associated interactions significantly affected ammonium (), nitrate nitrogen (), and total nitrogen (TN) content and photosynthetic characteristics of I. cylindrica. Additionally, interactions between soil type and AMF species significantly affected the biomass, plant height, and tiller number of I. cylindrica. Rhizophagus irregularis and Glomus claroideun significantly increased TN and content in the belowground components I. cylindrica in non-mineralized sand. Moreover, the inoculation of these two fungi species significantly increased belowground content in mineralized sand. The net photosynthetic rate positively correlated to aboveground total carbon (TC) and TN content under the high N and non-mineralized sand treatment. Moreover, Glomus claroideun and Glomus etunicatum inoculation significantly increased both net photosynthetic and water utilization rates, while F. mosseae inoculation significantly increased the transpiration rate under the low N treatment. Additionally, aboveground total sulfur (TS) content positively correlated to the intercellular carbon dioxide (CO2) concentration, stomatal conductance, and the transpiration rate under the low N sand treatment. Furthermore, G. claroideun, G. etunicatum, and F. mosseae inoculation significantly increased aboveground and belowground TC content of I. cylindrica, while G. etunicatum significantly increased belowground content. Average membership function values of all physiological and ecological I. cylindrica indexes infected with AMF species were higher compared to the control group, while corresponding values of I. cylindrica inoculated with G. claroideun were highest overall. Finally, comprehensive evaluation coefficients were highest under both the low N and high N mineralized sand treatments. This study provides information on microbial resources and plant-microbe symbionts in a copper tailings area, while aiming to improve current nutrient-poor soil conditions and ecological restoration efficiency in copper tailings areas.

Effect of Mycorrhiza fungi Glomus etunicatum on growth characteristics of barley which grown in nutrient solutions

This study was conducted at agricultural of plant production laboratories. The factorial experiment included studying the effect of two factors :First one : Urea at concentrations of (0 , 10 and 10 mg L-1 ) dissolved in tap water second factor : Treated with Mycorrhiza (Glomus mosseae) in seeds of barley .A Completely Randomized Design (C.R.D.) were used with four replicates and means were compared according to L.S.D. test at the level of 0.05. The results were summarized as follows: Mycorrhiza treatment was significantly superior in germination % ,plant height, fresh and dry weight of shoots and root s (41.3%, 10.44cm, 13.7g, 7.02g, 18.5g, 10.13g plant-1 ) respectively as well as Urea treatment(0.25g .L-1 ) was significant and superior compared to other treatments in fresh weight of vegetative and roots (6.5, 18.6 g.plant-1 . Results also indicated that the interaction of Mycorrhiza with urea 0.25g.L-1 had a significant increase in most of the studied indicators .

Effects of AMF on plant nutrition and growth depend on substrate gravel content and patchiness in the karst species Bidens pilosa L.

Karst ecosystems represent a typical heterogeneous habitat, and it is ubiquitous with varying interactive patches of rock and soil associated with differential weathering patterns of carbonate rocks. Arbuscular mycorrhizae fungi (AMF) play an important role in regulating plant growth and nutrition in heterogeneous karst habitats. However, it remains unclear how AMF affects the growth and nutrition of plants in heterogeneous karst soil with varying patches and weathering gravel. A heterogeneous experiment with Bidens pilosa L. was conducted in a grid microcosm through patching karst soil with different gravel contents. The experimental treatments included the AMF treatments inoculated with (M+) or without (M-) fungus Glomus etunicatum; the substrate patchiness treatments involved different sizes of the homogeneous patch (Homo), the heterogeneous large patch (Hetl), and the heterogeneous small patch (Hets); the substrate gravel treatments in the inner patch involved the free gravel (FG), the low gravel (LG) 20% in 80% soil, and the high gravel (HG) 40% in 60% soil. Plant traits related to growth and nutrients were analyzed by comparing substrate gravel content and patch size. The results showed that AMF was more beneficial in increasing the aboveground biomass of B. pilosa under the LG and HG substrates with a higher root mycorrhizal colonization rate than under the FG substrate with a lower root mycorrhizal colonization rate. AMF enhanced higher growth and nutrients for B. pilosa under the LG and HG substrates than under the FG substrate and under the Hets than under the Hetl. Moreover, AMF alleviated the limited supply of N for B. pilosa under all heterogeneous treatments. Furthermore, the response ratio LnRR of B. pilosa presented that the substrate gravel promoted the highest growth, N and P absorption than the substrate patchiness with M+ treatment, and the gravel content had a more effect on plant growth and nutrition as compared to the patch size. Overall, this study suggests that plant growth and nutrition regulated by AMF mainly depend on the substrate gravel content rather than the spatial patchiness in the heterogeneous karst habitat.

Effects and Molecular Mechanism of Mycorrhiza on the Growth, Nutrient Absorption, Quality of Fresh Leaves, and Antioxidant System of Tea Seedlings Suffering from Salt Stress

We studied changes in plant growth, nutrient absorption, quality of fresh leaves, and the antioxidant enzyme systems of leaves treated with AMF (Glomus etunicatum) in tea (tea cultivar “Xinyang 10”) seedlings exposed to 0 and 100 mmol/L sodium chloride (NaCl). The AMF colonization in the tea roots decreased observably by 50.1% after a 5-week soil NaCl (100 mmol/L) treatment. The growth, leaf nutrient levels, and leaf quality parameter contents significantly declined by 18–39% in the 100 mmol/L NaCl treatments. In contrast, these variables exhibited observably higher responses in the mycorrhizal seedlings than in the nonmycorrhizal seedlings. Furthermore, AMF improved the leaves’ total amino acid concentrations dramatically, accompanied by the upregulation of the genes of the amino acid synthetic enzymes, such as glutamate dehydrogenase (CsGDH), glutamate synthase (CsGOGAT), and glutamine synthetase (CsGS), while 100 mmol/L NaCl seedlings represented a negative performance. In addition, the 100 mmol/L NaCl treatments dramatically downregulated the expression level of the tea caffeine synthase 1 gene (CsTCS1), the ascorbate peroxidase gene (CsAPX), and the 3-hydroxy-3-methylglutaryl coenzyme gene (CsHMGR) in the leaves, while the AMF seedlings represented positive performances. These results suggest that AMF may play an active role in fresh leaf quality via the partial upregulation of the relevant genes’ expression. In contrast, salt stress represented the opposite result in tea. The seedlings inoculated with AMF showed significantly increased antioxidant enzyme activities, by 13.3–19.6%, including peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD), over the non-AMF inoculated tea seedlings. Still, they did not affect glutathione reductase (GR), irrespective of the NaCl condition. Further studies indicated that AMF observably upregulated the genes’ expressions (i.e., CsCAT and CsSOD) in both the 0 and 100 mmol/L NaCl seedlings. Meanwhile, the 100 mmol/L NaCl seedlings represented markedly lower antioxidant enzyme activities (i.e., SOD, CAT, and POD) and gene expressions (i.e., CsSOD and CsCAT) than the non-NaCl seedlings, irrespective of AMF inoculation. These results imply that AMF has a positive role in strengthening salt tolerance and on the quality of fresh tea leaves.

Karst Soil Patch Heterogeneity with Gravels Promotes Plant Root Development and Nutrient Utilization Associated with Arbuscular Mycorrhizal Fungi

Arbuscular mycorrhizal (AM) fungi associated with plant roots play an essential role in the belowground ecological process in karst habitats with high spatial and substrate heterogeneity. However, the effects of AM fungi on root morphology and nutrient uptake under different soil patch sizes and gravel content in karst habitats are still unclear. A controlled experiment was conducted using a square device divided into 16 grid patches. This experiment had three treatments, including the mycorrhizal fungal treatment inoculated with (M+) or without Glomus etunicatum Becker & Gerd (M−), the patch heterogeneity treatment through the homogeneous patch (Homo), heterogeneity-large patch (Hetl) and heterogeneity-small patch (Hets), and substrate heterogeneity treatment through the gravel-free substrate (GF), gravel-low substrate (GL), and gravel-high substrate (GH). Root traits and nutrients of Bidens pilosa L were analyzed, and the result showed the AM fungi significantly increased the dry weight, length, surface area, average diameter, volume, tips, branching points, and N, P, and K acquisitions of B. pilosa roots, but significantly decreased the specific root length. The Hets with soil and gravel increased the dry weight, length, surface area, tips, branching points, and N, P, and K acquisitions of B. pilosa roots compared with Hetl regulated by AM fungi. The GL and GH treatments also increased the dry weight, length, surface area, tips, branching points, and N, P, and K acquisitions of B. pilosa roots compared with GF regulated by AM fungi. These results indicate that the B. pilosa roots’ nutritional acquisition benefits were higher in Hets mixed with gravel for its root morphological development regulated by AM fungi in karst soil. In conclusion, we suggest that soil patch heterogeneity with gravels promotes root morphological development and nutrient utilization to karst plants associated with arbuscular mycorrhizal fungi.

Use of Symbiotic Fungi to Reduce the Phytotoxic Effect of DCD Nitrification Inhibitors in Lettuce

Nitrification inhibitors are commonly used to prevent nitrate leaching. However, the use of nitrification inhibitors is not free of side-effects. Some may be absorbed by the plant and cause phytotoxicity or even affect the food chain. Therefore, a solution that limits the absorption of nitrification inhibitors and its accumulation by the plant may mitigate health and environmental issues potentially associated with high levels of nitrification inhibitors. This solution may relay in the modulation of the plant’s metabolism through the interaction with specific fungal partners. This work tested the hypothesis that the symbiotic interaction between fungi and plant roots can reduce the destructive effects of the nitrification inhibitor Dicyandiamide (DCD) in plants by reducing the uptake of nitrification inhibitors. A greenhouse experiment was conducted, using a complete randomized block design, to test the effect of symbiotic fungi (plants inoculated with Piriformospora indica, Glomus etunicatum, and Glomus mosseae and noninoculated) on the phytotoxicity of DCD applied at four concentrations (0, 5, 50, and 100 mg kg−1 soil). Latuca sativa, cultivar Siyahoo, was selected for this experiment due to its economic value all over the world. The use of high DCD concentrations (100 mg kg−1 soil) affected the leaf chlorophyll content and plant growth in a manner that was significantly mitigated by the symbiosis of the plant with the fungal partner. These results highlight the benefits of using symbiotic fungal inoculants as plant protectors against the phytotoxic effects of DCD.

Different Arbuscular Mycorrhizal Fungi Established by Two Inoculation Methods Improve Growth and Drought Resistance of Cinnamomum Migao Seedlings Differently.

Simple SummaryDrought is a global climatic phenomenon and one of the main factors that negatively affect plant growth. Karst is a unique type of ecosystem where ecological degradation is becoming more and more serious due to the aggravation of global drought. Vegetation restoration is an effective method for preventing ecological degradation in Karst ecosystems. Cinnamomum migao is selected as the tree species for vegetation restoration, because it is a unique, fast-growing medicinal plant of Southwest China that only thrives in Karst regions. Arbuscular mycorrhizal fungi (AMF) are an important component of the soil biota in ecosystems and alleviate drought stress in plants by forming a mutualistic symbiosis. Most previous studies just considered the effects of AMF species on drought resistance but did not evaluate different inoculation methods. The aim of the present study was to compare the effects of different AMF resulting from the use of different inoculation methods on the growth and drought resistance of C. migao seedlings in Karst soil. The findings of this study will improve the success rate of reforestation programs in Karst ecosystems through the utilization of these important microorganisms.Drought stress is one of the greatest obstacles affecting field crop productivity in arid and semi-arid regions, and its severity and frequency are expected to increase due to human-induced changes to the environment and climate. Drought has led to rocky desertification in Karst regions. Cinnamomum migao is a unique, fast-growing medicinal plant of Southwest China that only thrives in Karst regions. Arbuscular mycorrhizal fungi (AMF) symbiosis alleviates drought stress in plants; however, establishment and function of the symbiotic interaction between AMF host plant in relation to the inoculation method remain unclear. Therefore, we conducted an experiment to investigate the effects of AMF species (Glomus etunicatum and Funneliformis mosseae) and two inoculation methods (seed vs. seedling inoculation) under drought stress on C. migao seedlings, and quantified mycorrhizal colonization, AMF spore density, root vigor, relative water content, C. migao growth, antioxidant enzyme activities, and osmotic adjustment. Inoculation with AMF (G. etunicatum and F. mosseae) positively affected the growth and root vigor of Cinnamomum migao under drought stress, regardless of the inoculation method. Additionally, both AMF species markedly upregulated antioxidant enzyme activities and osmotic adjustment substances, regardless of the inoculation method. Our results showed that the collective stimulatory effect of G. etunicatum is more efficient than that of F. mosseae. AMF application could promote afforestation with C. migao to prevent rocky desertification in Karst regions where water is the greatest limiting factor on plant growth and yield.

Diversity of vam in soils used to cultivate sugarcane (Saccharum spp.) in Tabasco, Mexico

E Objective: A study was carried out in the Ingenio Santa Rosalía sugar mill supply area with the aim of identifying the soil subunits cultivated with sugar cane and to quantify the degree of mycorrhization of Saccharum officinarum. Design/Methodology/Approach: Rhizosphere samples were collected at a depth of 0-30 cm and root segments with diameters of ≤ 1 mm and 1-2.0 mm were studied. The intersect method and the fungal structures method were comparatively analyzed to determine the mycotrophic state of the roots. The study also quantified the number of spores in the soils and classified the morpho-species of vesicular-arbuscular mycorrhiza (VAM). Results: The results show that seven soil subunits exist in the area, but the intersect method did not detect differences in colonization by root diameter or by root colonization ( = 68.5%). For its part, the fungal structures method showed differences in colonization between soil subunits ( = 69.5%), being higher in thin roots, and statistical differences wer found for vesicles and spores. At the sites, an average of 696 spores was quantified per 100 g of soil, which indicates a high presence of vesicular-arbuscular mycorrhizal fungi in the study area. Finally, six species of mycorrhizae were identified, of which four are present in various soil subunits: Glomus aff. deserticola, Glomus etunicatum, Glomus viscosum, and Paraglomus occultum. Study Limitations/Implications: This was an exploratory study that indicates the potential of VAM. Findings/Conclusions: The presence of hyphae, vesicles, arbuscules, and spores indicates that there is an active mycotrophic process between VAM and sugarcane cultivation in the soils of the study area.

Co-Inoculation of an Endophytic and Arbuscular Mycorrhizal Fungus Improve Growth and Yield of Helianthus tuberosus L. under Field Condition

Endophytic fungi (EPF) and arbuscular mycorrhizal fungi (AMF) symbioses can promote the growth and productivity of several types of plants. This work aimed to investigate the effect of co-inoculation of an EPF Exserohilum rostratum NMS1.5 and an AMF Glomus etunicatum UDCN52867 g.5 on the growth and yields of sunchoke (Helianthus tuberosus L.) compared to the effects of full-dose and half-dose chemical fertilizer (15–15–15) under field conditions. Several plant growth parameters of the co-inoculated plants were significantly higher than the other treatments. Remarkably, such an effect was relatively equal to that of the full-dose chemical fertilizers. Moreover, the co-inoculation of EPF and AMF significantly improved the tuber yield production, even better than the use of a chemical fertilizer. This is the first report to show that plant growth promoting effects of the co-inoculation of EPF and AMF were exceptionally greater than those of the chemical fertilizer. Therefore, our EPF and AMF could potentially be used as a biofertilizer for promoting the growth and yield of sunchoke in the fields.

Morphological and molecular identifications of three native arbuscular mycorrhizal fungi isolated from the rhizosphere of Elaeis guineensis and Jatropha curcas in Indonesia

Abstract. Rini MV, Yelli F, Tambunan DL, Damayanti I. 2021. Morphological and molecular identifications of three native arbuscular mycorrhizal fungi isolated from the rhizosphere of Elaeis guineensis and Jatropha curcas in Indonesia. Biodiversitas 22: 4940-4947. Molecular analysis has been widely used to provide more accurate identification within arbuscular mycorrhizal fungi (AMF) species than identification based on morphology. However, morphological analysis is essential for a basic preliminary of classification studies. Therefore, a study is needed to complete the identification of AMF isolates through morphological and molecular analyses. This research used three AMF isolates, namely MV 5, MV 17, and MV 18, which were isolated from Indonesian agricultural land. Spore-based taxonomy (shape, size, color, ornamentation, PVLG, and Melzer’s reaction) and fungal colonization on roots of maize trap plants were employed for the morphological studies. AMF species identification was performed using molecular analysis through nested-Polymerase Chain Reaction (PCR) to amplify a fragment of SSU rRNA followed by sequencing and phylogenetic tree construction. Morphological analysis showed that MV 5 had spores borne from the neck of the sporiferous saccule, MV 17 was found to have a bulbous suspensor without a germination shield, and MV 18 had spores borne from subtending hyphae. The SSUR rRNA analysis revealed that MV 5, MV 15, and MV 18 were identified as Acaulospora longula, Gigaspora margarita, and Glomus etunicatum, respectively. Both morphological and molecular methods demonstrated reliable and consistent results that complement AMF taxonomy studies.