Glomus Etunicatum Research Articles

Interactive effects of co-inoculation of Bradyrhizobium japonicum strains and mycorrhiza species on soybean growth and nutrient contents in plant

ABSTRACTThe main objective of this study was to investigate the effects of co-inoculation with different strains of Bradyrhizobium japonicum (i.e. Helinitro, Rizoking, and Nitragin) and arbuscular mycorrhizal fungi (AMF) species (i.e. Glomus fasciculatum, Glomus versiforme, Glomus intraradices, Glomus mosseae, and Glomus etunicatum) on soybean growth, fungal root colonization, and nutrient uptake of nitrogen (N), phosphorus (P), zinc (Zn), iron (Fe), and copper (Cu). Co-inoculation with various AMF species and rhizobia significantly (p<0.01) increased the soybean biomass production as compared to the non-inoculated controls. Furthermore, AMF colonization of roots of soybean plants increased by 79, 70.1, 67, 63, 57.5, and 50.1% in the presence of G. fasciculatum (GF), G. versiforme (GV), G. intraradices (GI), G. mosseae (GM), and G. etunicatum (GE), and Gmix (a mixed culture of fungi), respectively. Higher nutrient contents were observed in plants co-inoculated with Helinitro and GF. More insight into these results will enable optimization of the effective use of AM fungi in combination with their bacterial partners as a tool for increasing soybean yields in Iran; however, its general analytical framework could be applied to other parts of the world.

Response of a wild-type and modern cowpea cultivars to arbuscular mycorrhizal inoculation in sterilized and non-sterilized soil

ABSTRACTCowpea is an important crop that serves as a legume and vegetable source to many smallholder farmers in sub-Saharan Africa. Soil fertility is a significant limitation to its production thus; inoculation with beneficial soil biota such as arbuscular mycorrhizal fungi (AMF) could improve its performance. However, plant–AMF interaction could vary based on crop cultivar hence affecting overall crop production. The present study aimed at determining the effect of AMF inoculation and soil sterilization on root colonization and growth of a wild-type and three modern cowpea cultivars grown by smallholder farmers in Kenya. Potted cowpea plants were inoculated with a commercial AMF inoculum comprising of Rhizophagus irregularis, Funneliformis mosseae, Glomus aggregatum and Glomus etunicatum and maintained in a greenhouse for 40 days. After harvesting, mycorrhizal colonization, nodule number and dry weight, root and shoot dry weights, nitrogen (N,) phosphorus (P) and potassium (K) content were determined. Interestingly, the modern cultivars showed significantly (p < 0.001) higher root colonization, nodulation, shoot P and N compared to the wild-type cultivar. Moreover, a strong positive correlation between AMF root colonization and shoot P (r2 = 0.73, 0.90, p < 0.001), AMF root colonization and shoot N (r2 = 0.78; 0.89, p < 0.001) was observed in both sterilized and non-sterilized soil, respectively. Soil sterilization affected root colonization and growth parameters with plants grown in non-sterilized soil performing better than those grown in sterilized soil. This study provides major evidence that modern cowpea cultivars are still responsive to mycorrhizal inoculation suggesting that modern breeding programs are not deleterious AMF symbiosis.

Interação entre porta-enxertos de citros e fungos micorrízicos arbusculares

Arbuscular mycorrhizal fungi (AMF) support plant development, however, symbiosis depends on species of both symbionts. This study aimed to evaluate the interaction between rootstock citrus inoculated with species of arbuscular mycorrhizal fungi. Three rootstocks citrange ‘Fepagro C37 Reck’ [Poncirus trifoliata (L.) Raf. x Citrus sinensis (L.) Osbeck.], ‘Hong-Kong’ kumquat (Fortunella hindsii Swingle) and ‘Trifoliata’ (Poncirus trifoliate) were tested, inoculated with two species of AMF (Glomus etunicatum W.N. Becker & Gerd.and Acaulospora sp.) and a treatment not inoculated. We evaluated the height (cm), stem diameter (mm), leaf area (cm² / plant), leaf number, fresh and dry root and shoot weight (g), the level of reserves in tissues and the colonization of AMF in the roots. The species G. etunicatum and Acaulospora sp. colonized the roots of rootstocks, but they were only eff ective for ‘Fepagro C37 Reck’. Poncirus trifoliata had the highest vigor in the absence of AMF.

Belowground microbes mitigate plant-plant competition

Dimorphandra wilsonii, a Cerrado endemic Fabaceae tree, is threatened by land-use changes. The few remaining individuals occur in areas dominated by alien grasses like Urochloa decumbens. We tested the impact of nitrogen (N) availability and symbionts’ presence on mitigating the effects of competition from U. decumbens.Dimorphandra wilsonii seedlings were 50-week pot-cultivated under limiting (3mM) or non-limiting (10mM) N, with or without U. decumbens, and inoculated or not with a N-fixer (Bradyrhizobium sp.) and an arbuscular mycorrhizal fungus (AMF – Glomus etunicatum), both forming symbioses in the field.Since D. wilsonii seedlings grew more and ‘lost’ fewer nutrients under the symbionts’ presence, symbionts mitigated plant-plant competition. Under limiting N, inoculated D. wilsonii seedlings grew more (despite no nodulation), but N fixation was only suggested when inoculated D. wilsonii seedlings competed with U. decumbens. D. wilsonii13C, and substrate’s carbon and respiration suggest that only the microbes performing key functions received plant carbon. Under non-limiting N, inoculated D. wilsonii seedlings became enriched in 13C, substrate accumulated carbon and microbial respiration increased, suggesting a more generalist microbial community. Data suggest inoculating D. wilsonii seeds/seedlings with AMF and N-fixers as a conservation measure. However, long-term field-studies need to confirm these conclusions.

Arbuscular Mycorrhiza Augments Arsenic Tolerance in Wheat (Triticum aestivum L.) by Strengthening Antioxidant Defense System and Thiol Metabolism.

Arbuscular mycorrhiza (AM) can help plants to tolerate arsenic (As) toxicity. However, plant responses are found to vary with the host plant and the AM fungal species. The present study compares the efficacy of two AM fungi Rhizoglomus intraradices (M1) and Glomus etunicatum (M2) in amelioration of As stress in wheat (Triticum aestivum L. var. HD-2967). Mycorrhizal (M) and non-mycorrhizal (NM) wheat plants were subjected to four levels of As (0, 25, 50, and 100 mg As kg-1 soil). Although As additions had variable effects on the percentage of root colonized by the two fungal inoculants, each mycobiont conferred benefits to the host plant. Mycorrhizal plants continued to display better growth than NM plants. Formation of AM helped the host plant to overcome As-induced P deficiency and maintained favorable P:As ratio. Inoculation of AMF had variable effects on the distribution of As in plant tissues. While As translocation factor decreased in low As (25 mg kg-1 soil), it increased under high As (50 and 100 mg As kg-1 soil). Further As translocation to grain was reduced (As grain:shoot ratio) in M plants compared with NM plants. Arsenic-induced oxidative stress (generation of H2O2 and lipid peroxidation) in plants reduced significantly by AMF inoculation. The alleviation potential of AM was more evident with increase in severity of As stress. Colonization of AMF resulted in higher activities of the antioxidant enzymes (superoxide dismutase, catalase, and guaiacol peroxidase). It increased the concentrations of the antioxidant molecules (carotenoids, proline, and α-tocopherol) than their NM counterparts at high As addition level. Comparatively higher activities of enzymes of glutathione-ascorbate cycle in M plants led to higher ascorbate:dehydroascorbate (AsA:DHA) and glutathione:glutathione disulphide (GSH:GSSG) ratios. Inoculation by AMF also augmented the glyoxalase system by increasing the activities of both glyoxalase I and glyoxalase II enzymes. Mycorrhizal colonization increased concentrations of cysteine, glutathione, non-protein thiols, and activity of glutathione-S-transferase that facilitated sequestration of As into non-toxic complexes. The study reveals multifarious role of AMF in alleviation of As toxicity.

Arbuscular Mycorrhizal Colonisation Modifies the Water Relations of Young Transplanted Grapevines (Vitis)

The effect of arbuscular mycorrhizal (AM) colonisation on the alleviation of transplantation shock in young grapevines was investigated. One-year-old grapevines (Sauvignon blanc on Richter 99), colonised with Glomus etunicatum (Becker and Gerdemann), were cultivated in an atmosphere-controlled tunnel. Water relations, leaf photosynthetic parameters and growth characters were evaluated. AM colonisation enhanced the photosynthetic performance of host plants, but had no influence on biomass and mineral nutrition of the transplanted hosts. The increased photosynthetic rates of the AM plants were related to improved water relations. Stomata] conductance, transpiration rate and midday xylem water potential were higher in the AM hosts during the transplanted period. These results indicate that AM inoculation can influence the water relations of transplanted grapevine rootstocks, thereby improving photosynthetic performance and potential survival during the initial growth stages of the host plants.

How interacting fungal species and mineral nitrogen inputs affect transfer of nitrogen from litter via arbuscular mycorrhizal mycelium.

In the karst landscape, widespread in the world including southern China, soil nutrient supply is strongly constrained. In such environments, arbuscular mycorrhizal (AM) fungi may facilitate plant nutrient uptake. However, the possible role of different AM fungal species, and their interactions, especially in transferring nitrogen (N) from litter to plant, is poorly understood. We conducted two microcosm experiments to investigate the role that two karst soil AM fungi, Glomus etunicatum and Glomus mosseae, play in the transfer of N from decomposing litter to the host plant and to determine how N availability influences these processes. In experiment 1, Cinnamomum camphora tree seedlings were grown in compartments inoculated with G. etunicatum. Lolium perenne leaf litter labeled with δ15N was added to the soil in unplanted compartments. Compartments containing the δ15N labeled litter were either accessible to hyphae but not to seedling roots or were not accessible to hyphae or roots. The addition of mineral N to one of the host compartments at the start of the experiment significantly increased the biomass of the C. camphora seedlings, N content and N:P ratio, AM mycelium length, and soil microbial biomass carbon and N. However, significantly, more δ15N was acquired, from the leaf litter by the AM hyphae and transferred to the host when mineral N was not added to the soil. In experiment 2, in which C. camphora seedlings were inoculated with both G. etunicatum and G. mosseae rather than with G. mosseae alone, there was a significant increase in mycelial growth (50.21%), in soil microbial biomass carbon (417.73%) in the rhizosphere, and in the amount of δ15N that was transferred to the host. These findings suggest that maintaining AM fungal diversity in karst soils could be important for mediating N transfer from organic material to host plants in N-poor soils.

Arbuscular Mycorrhizal Fungi Improve the Antioxidative Response and the Seed Production of Suaedoideae Species Suaeda physophora Pall Under Salt Stress

Arbuscular mycorrhizal fungi (AMF) play a key role in plant growth and survival; however, the influence of AMF on the growth and production of Suaedoideae species is still not well understood. The object of this study was to understand the mechanism of AMF that affects the growth of Suaedoideae species under different saline conditions. The result showed that the Suaedoideae species Suaeda physophora was colonized by the AMF species Glomus etunicatum (Ge) and Glomus mosseae (Gm). AMF significantly increased the activities of superoxide dismutase (SOD) and peroxidase (POD) in S. physophora and reduced the concentrations of malondialdehyde (MDA) and H2O2 in the leaves of S. physophora under salt stress. AMF also improved the aboveground biomass of S. physophora and significantly increased its seed numbers. Moreover, AMF increased the aboveground phosphorus (P) content of S. physophora. No significant difference between the effect of AMF species Ge and Gm on S. physophora growth was observed. These results suggest that AMF can increase the salt resistance of the Suaedoideae species S. physophora by increasing SOD and POD activities, reducing MDA and H2O2 concentrations and increasing P uptake. The results highlight that AMF might play an important role in S. physophora growth and population survival under harsh salt conditions.

Influence of arbuscular mycorrhizal fungi on the vegetative development of citrus rootstocks1

ABSTRACT The use of arbuscular mycorrhizal fungi (AMF) in the production of rootstocks is an alternative to accelerate plant growth. However, their response depends on the symbionts species and environment. This study aimed at evaluating the influence of AMF species [Scutelospora heterogama, Gigaspora margarita, Glomus etunicatum, Acaulospora sp. and a control (non-inoculated)] on the vegetative development of citrus rootstocks {citrange 'Fepagro C37 Reck' [P. trifoliata (L.) Raf. x C. sinensis (L.) Osbeck.] and 'Kumquat' [Fortunella hindsii (L.) Swingle]}. The experimental design consisted of split-plot randomized blocks, with 10 plants per plot and 3 replications. Height, stem diameter, number of leaves, leaf area and fresh and dry root and shoot mass were evaluated. The colonization of AMF in the roots was also assessed, determining the percentage of colonization and density of hyphae, arbuscules and vesicles. The rootstocks showed no difference for the plant growth parameters, in the absence of AMF. The AMF species colonized the rootstocks roots, but were only effective in accelerating the citrange 'Fepagro C37 Reck' growth, especially when inoculated with Scutelospora heterogama, Gigaspora margarita and Glomus etunicatum. The influence of AMF on vegetative development depends on the citrus rootstock species.

Rhizosphere microbial impacts of alleviating faba bean Fusarium wilt with inoculating AM fungi

Greenhouse pot trials were conducted to investigate the effects of arbuscular mycorrhizal fungus (Glomus mosseae, Glomus tortuosum, Glomus intraradices and Glomus etunicatum) inoculation on the seedling growth, occurance of Fusarium wilt, population of Fusarium oxysporum and rhizosphere microbial community functional diversity in faba bean rhizosphere soil. Results showed that after inoculation of G. mosseae, G. tortuosum, G. intraradices and G. etunicatum, the shoot and root fresh mass of faba bean seedlings increased significantly, the disease index of faba bean fusarium wilt decreased significantly by 94.0%, 60.0%, 64.0% and 94.0%, respectively, the amount of F. oxysporum of faba bean rhizosphere decreased significantly by 98.6%, 74.3%, 77.8% and 90.4%, respectively. The best inhibitory effects to Fusarium wilt were with G. mosseae and G. etunicatum treatments. Inoculation of G. mosseae, G. tortuosum and G. etunicatum significantly increased carbon sources utilization ability of carbohydrates, amino acids, carboxylic acids and phenolic acids, with the average well color development (AWCD) value being increased by 34.4%, 31.5% and 50.8% respectively, but such significant differences were not observed with inoculation of G. intraradice. Principal component analyses showed that inoculation of G. mosseae, G. tortuosum and G. etunicatum fungi changed the rhizospheric microbial community composition. Correlation analyses showed that the utilization of carbohydrates carbon sources (β-Methyl-D-glucoside, D-Galacturonic acid, D-Mannitol, N-Acetyl-D-Glucosamine, D-Cellobiose,) and carboxylic acids carbon sources (D-Galactonic acid-γ-Lactone) were significantly increased after inoculation of G. tortuosum, and the utilization of L-Arginine and 4-Hydroxy benzoic acid significantly increased after inoculation of G. mosseae and G. etunicatum. Carbohydrates, carboxylic acids were main carbon sources utilized by rhizosphere microbes after G. tortuosum and G. intraradices inoculation, and amino acids and phenolic acids were main carbon sources utilized by rhizosphere microbes after G. mosseae and G. etunicatum inoculation. Inoculation of AM fungi significantly increased the activities of rhizosphere microbes, changed soil microbe community functional diversity, and thus inhibited the growth of F. oxysporum. The inhibitory impacts of AM fungi inoculations depended on the changes of microbes utilizing carbon sources.

English

The identification and the evaluation of arbuscular mycorrhizal fungi in the level of the root mycorhization were performed respectively from spores isolated from soil samplings and roots preleaved from the argan tree rhizosphere of seven sites in the region of Essaouira, Agadir, Taroudant and Tiznit (southwest Morocco). Analysis of the results revealed the presence in all samples of different characteristic of arbuscular endomycorrhizal structures. The frequency of mycorrhization was complete at Taroudant sites and Toufalazte (F = 100%) and between 50% and 33.33% in the Tamanar, Ait Melloul and Tiznit sites. The mycorrhizal intensity is high at the site of Toufalazte (57%) and low in Ait Melloul sites and Tiznit (between 1.83% and 1.93). Furthermore, the arbuscular contents are higher at the site of Toufalazte (24.16%) and lowest in the site of Tiznit (0.082%). The vesicular contents ranged from 0.21% (Ait Melloul) and 34.14% (Toufalazte). The density of spores in the rhizosphere of Argania spinosa also varied between 188 spores / 100 g soil (Toufalazte), and 28 and 44 spores / 100g of soil (Tiznit and Ait Melloul). The identification of isolated spores allowed to note the presence of 26 species of mycorrhizal fungi, divided into five genera (Glomus Scutellospora, Entrophospora, Pacispora, Gigaspora). Glomus etunicatum is the most abundant species, its frequency of occurrence reached 16.26%.

Response of arbuscular mycorrhizal fungi to soil phosphorus patches depends on context

Foraging strategies in arbuscular mycorrhizal fungi (AMF) for heterogeneously distributed resources in the soil remain to be explored. We used nylon-mesh bags of 30 μm to simulate patches of different phosphorus (P) supply levels (Expt 1) and P forms (organic v. inorganic, Expts 1 and 2). In Expt 1, host maize (Zea mays) was unfertilised; in each pot, five P-enriched bags were supplied with either Na-phytate or KH2PO4 at P rates of 0 (P0), 50 (P50), 100 (P100), 150 (P150) and 200 (P200) mg P kg–1. In Expt 2, maize plants were supplied with 20 (P20) or 50 (P50) mg P kg–1, and five P-enriched bags were supplied with different P forms (Na-phytate, lecithin, RNA, KH2PO4) and a nil-P control. Three fungal species (Funneliformis mosseae, Rhizophagus irregularis, and Glomus etunicatum) were compared in Expt 1, and the first two species in Expt 2. In Expt 1, the hyphal-length density (HLD) of G. etunicatum was not significantly different among different P levels when supplied with KH2PO4, whereas the HLD of R. irregularis tended to increase at higher P supply (above P50) in the Na-phytate treatment. The HLD of F. mosseae increased at P150 when supplied with KH2PO4, and increased at P100 and P150 in the Na-phytate treatment relative to P0. APase activity levels were more related to P supply level, in particular with F. mosseae inoculation and uninoculated control, showing that P200 significantly reduced APase relative to P0. In Expt 2, greater hyphal growth of both fungal species tended to occur with KH2PO4. At P20, the HLD of R. irregularis in treatments with KH2PO4 and lecithin, and of F. mosseae with KH2PO4, were higher than in P0. At P50, the HLD of F. mosseae was higher than of R. irregularis; but P form had no significant influence on HLD of F. mosseae, whereas the HLD of R. irregularis in the P-amended treatment (except with Na-phytate) was higher than in P0. APase activity did not differ significantly between the two fungal species. Highest APase activity generally occurred with lecithin, with no significant difference among the other P forms. Our results indicate that the response of AMF to P-enriched patches is complex, and both the form and amount of P supplied should be considered. Variations between AMF in the proliferation of hyphae to heterogeneous nutrient patches might be a mechanism by which these species can maintain diversity in intensive agricultural ecosystems.

Analysis of the effects of Glomus etunicatum fungi and Pseudomonas fluorescence bacteria symbiosis on some morphological and physiological characteristics of Mexican lime (Citrus aurantifolia L.) under drought stress conditions

To analyze the effects of Glomus etunicatum fungi and Pseudomonas fluorescence bacteria on some morphological and physiological characteristics of Mexican lime plant under drought stress conditions, a factorial experiment was conducted. This experiment was based on a completely randomized design with three replicates; each replicate was composed of two pots. The factors used consisted of G. etunicatum fungi and control, Pseudomonas fluorescence bacteria and control, and drought stress at three levels (-0.35, -0.47, and -0.6 bars). The analyzed characteristics were leaf chlorophyll content, leaf temperature, rate of net photosynthesis, transpiration, leaf relative water content (RWC), and percentage of root colonization. Data analysis revealed that both fungi and bacteria increased leaf chlorophyll content, net photosynthesis rate, transpiration, and leaf RWC. Moreover, the presence of fungi reduced leaf temperature while inoculation of bacteria had no effects on that the parameter. In addition, with the increase of irrigation periods, leaf temperature and transpiration were also increased. Results showed that root colonization percentage dropped with increased irrigation and the highest root colonization percentage was observed in simultaneous inoculations of fungi and bacteria with a two-day irrigation period.

CRESCIMENTO, ACÚMULO DE NUTRIENTES E FENÓIS TOTAIS DE MUDAS DE CEDRO-AUSTRALIANO (&lt;i&gt;Toona ciliata&lt;/i&gt;) INOCULADAS COM FUNGOS MICORRÍZICOS

http://dx.doi.org/10.5902/1980509820583O presente estudo teve por objetivo avaliar a produção de mudas de cedro-australiano quanto à capacidade de crescimento, nutrição e produção de fenóis totais inoculadas com fungos micorrízicos arbusculares (FMAs). Realizou-se experimento em casa de vegetação com três tratamentos compostos por Gigaspora margarita, Glomus clarum e Glomus etunicatum testados de forma isolada e quatro tratamentos compostos pela combinação destas espécies: Gigaspora margarita + Glomus clarum, Gigaspora margarita + Glomus etunicatum, Glomus clarum + Glomus etunicatum e Gigaspora margarita + Glomus clarum + Glomus etunicatum. Todos os tratamentos com o inóculo fúngico foram avaliados sem a adição de fósforo no substrato. Em comparação, foram utilizadas três testemunhas (sem fungo) contendo três doses de fósforo: 0, 50 e 100 mg dm-3, totalizando dez tratamentos. O delineamento experimental foi em blocos casualizados, com cinco repetições. Após 140 dias de germinação, foi observado que todas as espécies de FMAs inoculadas de forma isolada ou combinada promoveram benefícios significativos no crescimento, nutrição e produção de fenóis totais nas mudas de cedro-australiano em solos contendo baixa disponibilidade de fósforo. A mistura no solo de Gigaspora margarita, Glomus clarum e Glomus etunicatum foi capaz de proporcionar incrementos significativos no desenvolvimento das plantas na maioria dos parâmetros avaliados, obtendo-se desempenhos superiores ou equivalentes às plantas testemunhas não micorrizadas e cultivadas em solos adubados com fósforo. Isto sugere que os FMAs podem promover redução na adubação fosfatada no processo de produção de mudas de cedro-australiano.

Effects of simultaneous infections of endophytic fungi and arbuscular mycorrhizal fungi on the growth of their shared host grass Achnatherum sibiricum under varying N and P supply

Abstract Grasses can be infected by endophytic fungi and arbuscular mycorrhizal (AM) fungi simultaneously. Here, we investigated the interactions of a native grass, Achnatherum sibiricum , with both endophytic and AM fungi ( Glomus mosseae , GM and Glomus etunicatum , GE) at different nitrogen (N) and phosphorus (P) levels. The results showed that endophyte infection significantly suppressed the colonization rates and spore density of GE, but had no effect on those of GM. Endophyte infection increased shoot biomass regardless of the nutrient conditions. The effects of AM fungi on host growth were dependent on mycorrhizal species. There was no significant interaction between endophytic fungi and GE on host growth; however, a significant interaction between endophytic fungi and GE occurred in total phenolic concentrations and P uptake. As for GM, a significant interaction among endophytic fungi, AM fungi and nutrient availability occurred in shoot growth. Under sufficient N and P conditions, endophyte infection alleviated the detrimental effects of GM colonization on host growth.

Mycorrhizal colonization and diversity and corn genotype yield in soils of the Cerrado region, Brazil

The degree of interaction between arbuscular mycorrhizal fungi (AMF) and host plants appears to depend on plant genotype, which differentially promotes symbiosis and leads to different degree of mycotrophism. The aim of the present study was to assess root colonization, spore density, and diversity of AMF, as well as yield of corn (Zea mays) genotypes in soil from the Cerrado region of Brazil. Number of spores (NS), mycorrhizal colonization (COL), plant and ear height, dry weight (DW), and grain yield (GY) were assessed in inbred lines and their hybrids. Randomized blocks were used for the experimental design, with 30 treatments (genotypes) and three repetitions. The experiment was conducted on the farm of the UNESP-São Paulo State University, Campus of Ilha Solteira, and the plots were composed of two 2-m-long rows, with 0.85 m between rows, and 0.20 m between plants. Qualitative and quantitative changes were observed in fungal compositions, as well as preferential associations between symbiotic partners. Analysis of AMF diversity revealed the presence of 12 species, with Scutellospora calospora and Entrophospora colombiana being the most abundant in all treatments. The species Acaulospora longula, Glomus etunicatum, Glomus macrocarpum, and Gigaspora margarita exhibited preferential associations with certain genotypes. COL and GY differed among inbred lines and single-cross hybrids and the significant correlations between COL and the DW and GY showed positive interactions between the plants and AMF. There was no correlation between heterosis for GY and heterosis for colonization. These single-cross hybrids HS83 × E3 and D3 × F5 exhibited high GY, evidencing a productivity potential for the low technological condition used.

Mycorrhizal colonization and diversity and corn genotype yield in soils of the Cerrado region, Brazil

&lt;p&gt;The degree of interaction between arbuscular mycorrhizal fungi (AMF) and host plants appears to depend on plant genotype, which differentially promotes symbiosis and leads to different degree of mycotrophism. The aim of the present study was to assess root colonization, spore density, and diversity of AMF, as well as yield of corn (&lt;em&gt;Zea mays) &lt;/em&gt;genotypes in soil from the Cerrado region of Brazil. Number of spores (NS), mycorrhizal colonization (COL), plant and ear height, dry weight (DW), and grain yield (GY) were assessed in inbred lines and their hybrids. Randomized blocks were used for the experimental design, with 30 treatments (genotypes) and three repetitions. The experiment was conducted on the farm of the UNESP-São Paulo State University, Campus of Ilha Solteira, and the plots were composed of two 2-m-long rows, with 0.85 m between rows, and 0.20 m between plants. Qualitative and quantitative changes were observed in fungal compositions, as well as preferential associations between symbiotic partners. Analysis of AMF diversity revealed the presence of 12 species, with &lt;em&gt;Scutellospora calospora &lt;/em&gt;and &lt;em&gt;Entrophospora colombiana &lt;/em&gt;being the most abundant in all treatments. The species &lt;em&gt;Acaulospora longula&lt;/em&gt;, &lt;em&gt;Glomus etunicatum&lt;/em&gt;, &lt;em&gt;Glomus macrocarpum, &lt;/em&gt;and &lt;em&gt;Gigaspora margarita &lt;/em&gt;exhibited preferential associations with certain genotypes. COL and GY differed among inbred lines and single-cross hybrids and the significant correlations between COL and the DW and GY showed positive interactions between the plants and AMF. There was no correlation between heterosis for GY and heterosis for colonization. These single-cross hybrids HS83 × E3 and D3 × F5 exhibited high GY, evidencing a productivity potential for the low technological condition used.&lt;/p&gt;

Gene expression profiling of fatty acid biosynthetic pathway during interaction of oil palm (Elaeis guineensis Jacq.) with the mutualistic fungus Glomus etunicatum

In addition to the major phytohormone-mediated defense pathways, fatty acid (FA) pathways play significant roles in plant defense response and are involved in cross-talk with various phytohormones. Using volume-based analyses we have conducted a gene expression profiling of FA biosynthetic pathway during interaction of oil palm (Elaeis guineensis Jacq.) with the mutualistic fungus Glomus etunicatum. Inoculation with G. etunicatum stimulated growth and biomass production in oil palm. Here we demonstrated that there is an identical response in root and leaf tissues in gene expression during interaction of oil palm with G. etunicatum at different time points. We find that the expression of acetyl-CoA carboxylase (ACC), β-ketoacyl-ACP synthases (KAS) II and III, palmitoyl-ACP thioesterase (PTE), oleoyl-ACP thioesterase (OTE) and glycerol-3-phosphate acyltransferase (ACT) increased in both root and leaf tissues at 21 and 42 days post-inoculation (dpi). The expression level of these genes was up-regulated approximately threefold in both tissues at 63 dpi, which correlated with the colonization of roots with G. etunicatum and promotion of plant growth. These are likely to be key genes in the defense response of oil palm during symbiotic interaction with G. etunicatum. Together, the results provide a valuable resource to plant resistance mechanism and growth promotion with G. etunicatum. Given the capability of G. etunicatum to colonize oil palm root and enhance expression of FA pathway genes, it is suggested that the fungus has evolved efficient strategies to overcome plant immunity. The fungus can be used to establish a proper transformed progeny of oil palm with increase resistance to biotic stress and promote healthy growth for better oil yield.

Potential Selection of Arbuscular Mycorrhizal Fungi (AMF) Indigenous Ultisols through the Production of Glomalin

The arbuscular mycorrhizal fungi ( AMF ) with plants able to increase the capacity of plants to absorb nutrients and water from the soil. Recently, research was indicated that AMF hyphae containing glomalin as a glycoprotein that serves to unify the dispersed soil particles. The content of glomalin in soil is positively correlated with soil aggregate stability. The research potential of AMF species indigenous of Ultisol Darmasraya District of West Sumatra and glomalin production in experimental pots of sterile sand medium has been carried out. The purpose of this study was to determine the diversity of AMF species on Ultisol and to seeking indigenous AMF isolates that had the best glomalin production capability. AMF spores were isolated and identified from the rhizosphere soil of corn in Ultisol. AMF species that had been identified experimentally were tested in culture medium pot of sand and zeolite (w / w 1:1) using corn crops. The results found nine of the AMF species indigenous of Ultisol Darmasraya, namely Acaulospora scrobiculata, Glomus etunicatum, Glomus luteum, Glomus mosseae, Glomus verruculosum, Glomus versiforme, Scutellospora gregaria, Scutellospora heterogama and Gigaspora sp. AMF species that showed better colonization ability in corn was G. luteum, G. verruculosum and G. versiforme. All three species produced glomalin significantly higher than the other species, i.e. 1.29 mg g-1; 1.17 mg g-1; 1.15 mg g-1, respectively. [How to Cite: Eddiwal, A Saidi, I Lenin, EF Husin and A Rasyidin. 2014. Potential Selection of Arbuscular Mycorrhizal Fungi (AMF) Indigenous Ultisols through the Production of Glomalin. J Trop Soils 19: 181-189. Doi: 10.5400/jts.2014.19.3.181]

Arbuscular mycorrhizal fungal association in Asteraceae plants growing in the arid lands of Saudi Arabia

The present research was undertaken to explor the possibility of arbuscular mycorrhizal (AM) association with Asteraceae plants in the arid lands of Saudi Arabia (Al-Ghat, Buraydah, Thumamah and Huraymila). AM fungal colonization in the roots, spore numbers in the rhizosphere soil, fungal species diversity and correlation between AM properties and soil properties were determined. The highest colonization was in Conyza bonariensis (65%) from Al-Ghat, Anthemis cotula (52%) from Buraydah and C. bonariensis (53%) from Thumamah. The lowest was in Vernonia schimperi (41%) from Al-Ghat, Pulicaria undulata (25%) from Buraydah, Acanthospermum hispidum (34%) from Thumamah, Asteriscus graveolens (22%) and V. schimperi (22%) from Huraymila. Vesicular and arbuscular colonization were also presented in all plant species examined. The number of spores were 112–207 in Al-Ghat, 113–133 in Buraydah, 87–148 in Thumamah and 107–158 in Huraymila. Funneliformis mosseae, Glomus etunicatum, G. fasciculatum and G. aggregatum were identified. Relative frequency of AM fungal species varied widely and was irrespective of location and plant species. Diversity index varied with the rhizosphere soils of different plant species at various locations. Soil properties varied with locations and no distinct correlations were observed among the soil properties, root colonization and the number of spores. The results of the present study specified the association of AM fungi in different plants of Asteraceae and its significance in the ecological functioning of annual plants in the punitive environments of the rangelands in Saudi Arabia.