Arbuscular Mycorrhizal Fungi Species Diversity Research Articles

Impact of wildfire on soil characteristics and arbuscular mycorrhizal fungi.

This study explored whether wildfire alters the soil properties and arbuscular mycorrhizal fungi (AMF) community composition when compared with burnt rangeland, non-burnt rangeland and adjacent tilled in mesothermal ecosystems. The study was carried out in August 2020, 1year later after wildfire. The results of this study showed that the wildfire played a key role in altering soil characteristics and AMF community composition in Bartin Province located in the Western Black Sea Region. Soil samples were made according to standard methods. AMF spores were isolated according to the wet sieving method, and the spores of AMF were identified according to their morphological characteristics. Analysis of variance was performed to determine the differences between the parameters, and correlation analysis was performed to determine the relationships between the parameters. The highest values of soil organic carbon (2.20%), total nitrogen (0.18%), K2O (74.68kg/da), root colonization (87.5%) and the frequency of occurrence of Funneliformis geosporum (20%), Claroideoglomus claroideum (16%) and Claroideoglomus etunicatum (11%) were found in burnt rangeland. Sporulation of Acaulospora dilatata, Acaulospora morrowiae, Acaulospora tuberculata, Scutellospora castanea, Scutellospora coralloidea, Scutellospora scutata, Glomus coremioides and Glomus multicaule was either decreased or completely inhibited in the burnt rangeland. While species diversity of AMF (12) decreased, the number of AMF spores (325.6 (number/50 gr soil)) increased in burnt areas. In conclusion, the number of spores and root colonization of AMF increased but species diversity of AMF reduced after the wildfire. In ecosystems with high fire risk where AMF transfer is planned, it is suggested that it would be more appropriate to select species with an increase in spore number after fire.

EFFET DE LORPAILLAGE SUR LABONDANCE ET LA DIVERSITE DES ESPECES DE CHAMPIGNONS MYCORHIZIENS ARBUSCULAIRES DANS LA REGION CENTRALE DU TOGO

Gold mining has a negative impact on the soil include microorganisms such as Arbuscular Mycorrhizal Fungi (AMF). The AMF form associations with plants by improving their development However, the effect of gold mining on Arbuscular Mycorrhizal Fungi (AMF) living in its soils is poorly understood.The objective of this study was to characterize the effect of gold mining on the abundance and diversity of AMF species in the Central region of Togo. The AMF were extracted by wet sieving from 200g of soil samples taken directly from four types of soil, Gold Soil (SA), Washed Gold Soil (SAL), Soil Under Corn Cultivation (SSCM) and the Soil Under Natural Vegetation (SSVN). The diversity of AMF was determined by diversity indices. The results showed that SA, SSCM and SSVN had significantly higher AMF fungal spores densities (p < 0.05) than SAL. AMF species richness was generally lower in SAL (12 species out of a total of 30 species identified). A total of 30 AMF species classified into 16 genera, in 9 families (AcaulosporaceaeAmbisporaceae, Archaeosporaceae, Gigasporaceae, Claroideoglomeraceae, Dentiscutataceae, Diversisporaceae, Glomeraceae, Paraglomeraceae) were identified. The most frequent species were Acaulosporascorbiculata, Acaulospora sp., Entrophosporainfrequens, Gigaspora gigantea, Claroideoglomusetunicatum. The most abundant species were Acaulosporascorbiculata, Acaulosporasp., Entrophosporainfrequens, ClaroideoglomusEtunicatum, Glomus clavisporum, and Rhizophagusintraradices. The biological diversity indices (Shannon and Pielou equitability) revealed a significant difference (P < 0.05) between the different types of soils studied. The density of the spores as well as their diversityvary as follows: SAL<SA< SSVN< SSCM. The soils of the study area contain a great natural wealth of AMF species, but this natural wealth is significantly affected by gold panning. The native AMF found in these areas could be used for the ecological restoration of degraded gold panning areas.

Diversity of Arbuscular Mycorrhizal fungi under different agroforestry practices in the drylands of Southern Ethiopia

The conversion of an agroforestry based agricultural system to a monocropping farming system influences the distribution and composition of arbuscular mycorrhizal fungi (AMF). The aim of this paper was to analyze AMF species diversity, spore density, and root colonization across different agroforestry practices (AFP) in southern Ethiopia. Soil and root samples were collected from homegarden, cropland, woodlot, and trees on soil and water conservation-based AFP. AMF spores were extracted from the soil and species diversity was evaluated using morphological analysis and root colonization from root samples. The AMF spore density, root colonization and composition were significantly different among the AFP (P < 0.05). In this study, 43 AMF morphotypes belonging to eleven genera were found, dominated by Acaulospora (32.56%), followed by Claroideoglomus (18.60%). Home gardens had the highest spore density (7641.5 spore100 g− 1 dry soil) and the lowest was recorded in croplands (683.6 spore100 g− 1 dry soil). Woodlot had the highest root colonization (54.75%), followed by homegarden (48.25%). The highest isolation frequency (63.63%) was recorded for Acaulospora scrobiculata. The distribution of AMF species and diversity were significantly related to soil total nitrogen and organic carbon. The homegarden and woodlot AFP were suitable for soil AMF reserve and conservation.

Morphological and Molecular Characterizations of Arbuscular Mycorrhizal Fungi and Their Influence on Soil Physicochemical Properties and Plant Nutrition.

Pulses are considered a remarkable and stable source of nutrients, which are being presently extensively cultivated and consumed in different parts of the world. Pulses belong to the family Leguminosae and are a rich source of nutrients such as phosphorus (P) and nitrogen (N) for best growth via symbiotic relationship with bacteria and AMF (arbuscular mycorrhizal fungi). The aim of the current study was evaluating the influence of AMF diversity associated with various pulses (French bean, mung bean, kidney bean, peas, soybean, peanuts, and grams). Furthermore, AMF characterization was done using morphological features of spores and sequencing of the rDNA gene, which confirmed the existence of 10 different AMF taxa. Among the different genera, the genus Glomus was observed to be the most dominant with 30% species followed by Gigaspora (22%), Sclerocystis (12%), Acaulospora (8%), Rhizophagus and Septoglomus (7%), Diversispora (5%), and Claroideoglomus, Archaeospora, and Ambispora (3%). Furthermore, soil physicochemical analysis and percentage of AMF colonization results revealed the fact that the phosphorus content (inversely proportional to the AMF diversity) was a determining factor of AMF diversity. The highest amount of available phosphorus (62.825 mg kg-1) in the district Swabi resulted in a low rate of AMF colonization (6.66 ± 11.54%) with a comparatively higher rate of AMF colonization (50.66 ± 1.15%) found in the soil of the district Chitral having a low phosphorus content (17.3 ± 7.6 mg kg-1). Nutrient uptake by pulses including nitrogen (2.4 ± 1.3%), phosphorus (13.5 ± 7.6 mg kg -1), potassium (99.5 ± 25.8 mg kg -1), zinc (1.4 ± 0.5 mg kg -1), moisture (2.3 ± 1.3%), crude fats (5.6 ± 2.8%), ash (4 ± 1.2%), and proteins (13.6 ± 9.01%) determined the fact that AMF species diversity is positively correlated to the plant mineral nutrition. From the current study, it is concluded that AMF inoculation to the soil fields is beneficial to ensure the sustainability and productivity of pulse crops in diverse environmental conditions without polluting the soil.

Electrical Conductivity and pH Are Two of the Main Factors Influencing the Composition of Arbuscular Mycorrhizal Fungal Communities in the Vegetation Succession Series of Songnen Saline-Alkali Grassland.

Arbuscular mycorrhizal fungi (AMF) are widely distributed microorganisms in the soil, playing an important role in vegetation succession, plant community diversity, and improving soil physicochemical properties. In this study, morphological identification and high-throughput sequencing technology were used to comprehensively analyze the AMF community composition and diversity at different succession stages of Songnen saline-alkali grassland. To determine the root colonization status of plants collected in the field, a colonization system was established using late-succession plants as host plants to verify the existence of mycorrhizal symbiosis and the matching phenomenon of AMF in Songnen saline-alkali grassland. The results indicated that both morphological methods and high-throughput sequencing technology showed that glomus was the dominant genus of AMF in Songnen saline grassland. Redundancy analysis (RDA) and linear regression analysis showed that electrical conductivity (EC) and pH were the main environmental factors affecting AMF species diversity and community structure in the succession sequence of Songnen saline grassland. In addition, the results of root colonization identification and the colonization system test in the field showed that AMF successfully colonized vegetation at different succession stages and had mycorrhizal symbiosis. The results of this study could help to understand the AMF community of Songnen saline-alkali grassland as well as provide a reference and basis for optimizing the AMF community structure of Songnen saline-alkali grassland through human intervention in the future and using mycorrhizal technology to restore and rebuild the degraded ecosystem of Songnen saline-alkali grassland.

Durum wheat-lentil relay intercropping enhances soil mycorrhizal activity but does not alter structure of arbuscular mycorrhizal fungal community within roots

In intercropping systems, crop species select host-adapted microorganisms and influence the associated plant-microbial interactions like in the case of arbuscular mycorrhizal fungi (AMF). Attempts to assess the impact of intercropping on the activity, diversity, and community composition of AMF remain inconclusive, more so in intercropping systems involving traditional Mediterranean crops such as durum wheat and lentils. We carried out field experiments in Central Italy to assess the impact of relay intercropping durum wheat (Triticum durum Desf. cv. Minosse) and lentil (Lens culinaris Medik. cv. Elsa) on soil mycorrhizal inoculum potential (MIP) (2019 and 2020), AMF root colonization (2019, 2020, and 2021), and root AMF diversity and community composition (2020 and 2021), compared to the respective sole crops. Results showed that relay intercropping enhanced lentil grain yield and durum wheat grain protein concentration but marginally reduced durum wheat grain yield and lentil grain protein concentration. In addition, relay intercropping enhanced soil mycorrhizal activity but differentially influenced mycorrhizal root colonization compared to sole cropping. Sequencing analyses generated a total of 234 amplicon sequence variants belonging to Glomeromycota, which were assigned to 31 virtual taxa using the MaarjAM reference database. Glomeraceae and Claroideoglomeraceae were the most abundant taxa but had contrasting abundances in 2020 and 2021. The overall changes in AMF species diversity and community structure were affected by the interaction between crop species and year, and not by intercropping. Claroideoglomus and Septoglomus showed a strong association with lentil roots while Rhizophagus and Paraglomus were associated with durum wheat roots in 2020, affirming host genotype-AMF preferences. The principal component analysis showed that grain protein concentration was associated with selected mycorrhizal parameters such as community richness and AMF root colonization. Further studies on the functional analysis of the different AMF communities selected by the crop genotype and year may reveal the importance of intercropping in maintaining soil functionality and productivity under low-input systems.

Impact of long-term application of paclobutrazol in communities of arbuscular mycorrhizal fungi and their efficiency in the development of Helianthus annuus L.

Paclobutrazol (PBZ) is a phytoregulator known for inhibiting plant vegetative growth and promoting flowering in mango crop (Mangifera indica L.). PBZ belongs to the triazole family, a group recognized by its fungicide capacity, and its application to the soil can directly influence microbial communities, however, little is known about its effects on arbuscular mycorrhizal fungi (AMF). The objectives of this work were to evaluate the impact of long-term application of PBZ on the AMF communities and to verify whether the management time affects the functionality of these communities in promoting the development of ornamental sunflower Helianthus annuus L. (var. Dwarf Double Sungold). Sampling was carried out in mango cultivation areas with a history of PBZ application that varied from no application to application for up to 15 years. For the analysis of the AMF community, the quantification of most probable number (MPN) of infective AMF propagules, abundance of glomerospores, richness, diversity, Simpson dominance, and Pielou's evenness were evaluated. The analysis of the functionality of the AMF community was based on the analysis of the variables of growth and mycorrhizal colonization. Soils with a prolonged history of PBZ application (>nine years) presented distinct AMF communities with lower abundance of glomerospores in relation to areas without PBZ application and with native Caatinga vegetation. However, the soil-inoculum of this AMF community has greater efficiency in promoting sunflower development and mycorrhizal colonization, suggesting greater functionality. It is concluded that the time of application and performance of PBZ in the soil influence the composition of the AMF community. Even with reduction of richness and diversity of AMF species in soils with a prolonged history of PBZ application, there are functional AMF communities in these soils that promoted sunflower plant growth, selecting more efficient and resistant species.

Checklist of the arbuscular mycorrhizal fungi of Oaxaca, an important hotspot of biodiversity in Mexico

Background: Oaxaca, a southern State in Mexico, belongs to the Mesoamerican hotspot of biodiversity. The taxonomic and diversity knowledge of arbuscular mycorrhizal fungi (AMF) in Oaxaca State is scattered and accessibility to it is difficult.&#x0D; Questions: Which AMF species have been identified in Oaxaca and which is their distribution?&#x0D; Studied species: Arbuscular mycorrhizal fungi.&#x0D; Study site: State of Oaxaca, Mexico.&#x0D; Methods: It was prepared an updated and annotated checklist of the AMF species with frequency of occurrence and the sampling sites where the species had been registered. All studies carried out previously (to date, 2022) were considered. Information on AMF taxa was available in scattered form in different publications in physical and electronic media, theses, projects, technical reports, and scientific papers.&#x0D; Results: The checklist includes 78 species, distributed among 23 genera, 10 families, and four orders. The most diverse families were Glomeraceae (26 species), followed by Gigasporaceae (20) and Acaulosporaceae (15), whereas the most diverse genera were Acaulospora and Glomus (15 and eight species, respectively). The most frequent species were Funneliformis geosporus, Acaulospora scrobiculata, and A. spinosa. The highest species diversity has been reported under the rhizosphere of Agave angustifolia, A. karwinskii, and Zea mays (39, 36, and 34 species, respectively). A new AMF species was recently isolated from the rhizosphere of a microendemic agave.&#x0D; Conclusions: The recorded AMF species of Oaxaca State confirms its position as one of the states with the highest AMF species diversity of Mexico.

Abundance and distribution of arbuscular mycorrhizal fungi associated with oil-yielding plants.

Due to their role in nutrient transmission, arbuscular mycorrhizal fungi (AMF) are widespread plant root symbionts. They may improve plant production by altering plant community structure and function. Therefore, a study was conducted in the state of Haryana to analyze the distribution pattern, diversity, and association of different AMF species with oil-yielding plants. The results of the study revealed the percentage of root colonization, sporulation, and diversity of fungal species associated with the selected 30 oil-yielding plants. The percentage root colonization ranged from 0% to 100%, the highest in Helianthus annuus (100.00 ± 0.00) and Zea mays (100.00 ± 0.00) and the least in Citrus aurantium (11.87 ± 1.43). At the same time, there was no root colonization in the Brassicaceae family. The number of AMF spores present in 50 g of soil samples varied from 17.41 ± 5.28 to 497.2 ± 8.38, with maximum spore population in Glycine max (497.2 ± 8.38) and minimum in Brassica napus (17.41 ± 5.28). Besides, the presence of several species of different genera of AMF was reported in all the studied oil-yielding plants, that is, 60 AMF belonging to six genera viz. Acaulospora, Entrophospora, Glomus, Gigaspora, Sclerocystis, and Scutellospora were observed. Overall, this study will promote AMF usage in oil-yielding plants.

Root system-rhizosphere soil-bulk soil interactions in different Chinese fir clones based on fungi community diversity change

The diversity of the rhizosphere arbuscular mycorrhizal fungi (AMF) community is a crucial factor affecting root-soil interaction. They can absorb carbohydrates from the host body and return the nutrient elements from the soil to the host. Using 15 Chinese fir (Cunninghamia lanceolata Lamb. Hook.) clones, the AMF richness, abundance and community structure in “Root system-Rhizosphere soil-Bulk soil” were obtained by Real-time quantitative PCR (qPCR) and Illumina Miseq sequencing techniques. The results showed that under the same Chinese fir clone, the total amount of AMF was in the order of rhizosphere soil &amp;gt; root system &amp;gt; bulk soil. The species diversity and uniqueness of AMF were in the order of root system &amp;gt; rhizosphere soil &amp;gt; bulk soil. There was a significant correlation between soil-available phosphorus and AMF diversity and its dominant genera and species. Regarding AMF abundance, Chinese fir clone S18 is the highest, followed by clones Y061 and P17. There was a significant difference in AMF richness among different clones, and Glomus was the dominant genus of AMF. The AMF species diversity of P17 and S2 in roots and rhizosphere soil was high, indicating a good symbiosis between roots and the AMF community. However, the AMF diversity of clones P11 and P41 was low, and the variation of AMF community composition in the group was small. The root-soil interaction caused the AMF community to gather in the rhizosphere but had less symbiosis present with roots. Still, the AMF diversity of the rhizosphere soil of both clones was high. There was a significant correlation between the soil-available phosphorus content and the species diversity of AMF and its dominant genera and species. In conclusion, Clone P17 has high AMF richness and abundance and forms a good symbiosis with AMF, which could be a nutrient-efficient clone of Chinese fir.

English

The papaya tree is not very exploitable on the international market because of the post-harvest decline of the fruits. In this study, we identified arbuscular mycorrhizal fungi (AMF) from the rhizosphere of papaya in two agroecological zones of Cameroon (Njombe-Pendja: NP and Yaounde: Y). Morphological studies on the density, the rate of root colonization, the diversity of AMF species were evaluated. Molecular identification of AMF was performed by sequencing the small subunit (SSU) 18S rDNA gene region from soil samples. These genes were amplified from the AML and NS2 primers. The total number of spores per 100 g of dry soil was significantly different (P&lt;0.05) depending on the sites, ranging from 391 in NP to 790 in Y sites. The frequency and intensity of root colonization was not significantly different in the two sites. Eleven (11) AMF belonging to seven (7) genera (Scutellospora, Gigaspora, Acaulospora, Entrophospora, Funneliformis, Glomus and Racocetra) were recorded. Two AMF species (T1: Scutellospora rosa and T6: Racocetra gregaria) were recorded at NP and absent at Y. The Shannon-Wiener index revealed a low diversity of AMF species. Homogeneity of species was recorded. Molecular analysis reveals that the AMF species obtained have sizes of 250 bp. Key words: Arbuscular mycorrhizal fungi, Carica papaya L., fungal, molecular and morphological identification, rhizosphere.

Effects of no-tillage and biologically-based organic fertilizer on soil arbuscular mycorrhizal fungal communities in winter wheat field

Communities of arbuscular mycorrhizal fungi (AMF) in soil are impacted by agricultural management, which in turn influences crop growth and yield. Yet the combined effects of tillage and fertilization practices upon AMF communities are still poorly understood. This study investigated the interactive effects of tillage (no-tillage and conventional tillage) and fertilization (no-fertilization and biologically based organic fertilization) factors on AMF community structure and yield of winter wheat field. The five-year field experiment was conducted in Longde County, Ningxia, China. Results indicated that no-tillage significantly increased the species richness, evenness, and diversity of soil AMF, whereas bio-organic fertilization was less influential. Under no-tillage, bio-organic fertilization marginally increased the richness and diversity of AMF species; however, under conventional tillage this effect was inversed. Glomus, Claroideoglomus, and Paraglomus AMF genera dominated under no-tillage combined with bio-organic fertilization. No-tillage increased the relative abundance of Glomus, while bio-organic fertilization increased that of Claroideoglomus. Redundancy analysis revealed that total nitrogen and available phosphorus were the most important soil variables related to the diversity and community composition of AMF. The yield of winter wheat was negatively correlated with AMF diversity and positively correlated with Glomus abundance. This study suggests that, compared to single conservation agricultural practices, combining no-tillage with bio-organic fertilization may further improve the benefits of soil AMF for winter wheat crops. However, under low nitrogen and phosphorus inputs, conventional tillage can accelerate the mineralization of organic matter and increase the availability of soil nutrients, thereby improving wheat yield.

Seasonal variation of arbuscular mycorrhizal fungi in ecotone forests of the northern region of Brazilian Amazonia

The ecotone forests in the northern region of Brazilian Amazonia are important areas representing transition zones between forest and non-forest ecosystems. These areas have soils nutrient-poor that poorly drain. Under these environmental conditions, Peltogyne gracilipes (Leguminoseae), an endemic tree species, can form natural monodominant forests. Here, we assessed the arbuscular mycorrhizal fungi (AMF) community in three forest types on the eastern side of Maracá Island and the relationship of these microorganisms with the monodominance of P. gracilipes. In this study, soil samples were collected in two seasons (dry and rainy). The samples were collected in 9 plots, in rich areas, poor areas and areas without P. gracilipes. Soil samples were evaluated for chemical and particle size analysis, spore density and morphology, and identification of AMF. AMF species were identified using two approaches: spores collected in the field and trap cultures. Eighteen and 13 AMF species were identified in the dry and rainy seasons, respectively, for spores extracted from the field. Six total species were detected exclusively in trap cultures in the dry season. AMF communities were co-dominated by members of the Gigasporaceae, Acaulosporaceae and Glomeraceae families. Redundancy analyses indicated that several soil attributes, such as pH, Fe, Mg, and sand content associated with the AMF species richness in both seasons. We conclude that the ecotone forests in the eastern region of Maracá Island are home to important richness and diversity of AMF species and that various soil factors influence the composition of the AMF community in this ecosystem.

ARBUSCULAR MYCORRHIZAL FUNGI IN THE CERRADO BIOME: EFFECTS OF LAND USE SYSTEM, SOIL TEXTURE, AND SEASONALITY

ABSTRACT The objective of this study was to identify communities of arbuscular mycorrhizal fungi (AMF) in soils under pasture, silvopasture, and Cerrado forest ecosystems, and evaluate the effects of land use system, soil texture, and seasonality on the dynamics of AMF communities, in Alta Floresta D'Oeste, Rondônia, Brazil. Samples of the soil 0-20 cm layer were randomly collected in each ecosystem in July, 2010 (dry season) and January, 2011 (rainy season). Spores were extracted, counted, and identified. The spore density and density of each species of AMF were estimated. The frequency of occurrence, Shannon diversity index, and Simpson diversity index were calculated for each species. Multivariate clustering analysis was carried out, considering the number of AMF of each species. The results showed a trend of higher number of spores in the Cerrado forest ecosystem, regardless of the soil texture or season, when compared to pasture and silvopasture areas. The Glomus macrocarpum species presented 100% frequency of occurrence in the rainy season in both soil textures. The effects of texture and seasonality on the composition and diversity of AMF communities was more expressive in the Cerrado forest ecosystem. The climate, soil texture, and land use and management affected the composition and diversity of AMF species.

Diversity of Arbuscular mycorrhizal Fungal Association with Quercus oblongata D. Don

Arbuscular mycorrhizal fungi (AMF) form a pervasive, obligate, mutualistic association with plant roots to help and play an important role in their life. In the current study, the species diversity of AMF in the rhizosphere of Quercus oblongata D. Don was studied. Rhizospheric soil samples and roots were collected from three different locations (Ropadi Gad, Sakaryar, and Saron). The occurrence of AMF, species composition and the diversity of AM fungi were observed with Q. oblongata plants. At all the 3 locations, selected plants were found to be colonized with AMF, however, the extent of root colonization significantly varied at different locations. Morphologically different 12 AMF species were isolated and identified from the rhizosphere of Q. oblongata. Of those 12 AMF species, six were found from the Ropadi Gad location, seven from the Sakaryar, and the remaining five from the Saron location. The highest root colonization was observed in Q. oblongata at Sakaryar (53.32%), followed by Ropadi Gad (46.67%), while the least was observed at Saron (40.40%). The number of spores ranged from 185±2.54 to 312±3.60, with an average of 250.33±3.32 per 100 g of air-dried soil. The number of spores exhibited a significant positive correlation with root colonization. The number of arbuscules and vesicles also followed the same trend viz. the maximum number of arbuscules and vesicles at Sakaryar, followed by Ropadi Gad, and with a minimum at Saron.

Diversity of Arbuscular Mycorrhizal Fungi Species Associated with Soybean (&amp;lt;i&amp;gt;Glycine max&amp;lt;/i&amp;gt; L. Merill) in Benin

Arbuscular Mycorrhizal Fungi (AMFs) could be used to sustainably improve crop yields. The present study evaluated the diversity of AMF species associated with soybean (Glycine max L. Merill) in main soybean-producing areas in Benin. Composite soil samples from 13 production areas at a rate of 04 villages per production areas were collected. A spore trapping device was set up to reveal the diversity of spores. The physical and chemical properties of the soils, the frequency and intensity of mycorrhization of roots, and the diversity of AMF spores were determined in the soil samples following trapping. As result, eight morphotypes belonging to four genera: Glomus, Acaulospora Gigaspora and Disversispora and three families: Diversisporales, Glomérales and Paraglomérales were observed. An important variability of spore densities was observed from one production areas to another with a higher abundance in the production areas of Copargo estimated at 3584 spores/100g soil. The biological diversity indexes as Shannon (0.0311), Simpson (0.0204) and Hill (0.0235), varied significantly (p < 0.05) from one production areas to another. There was significant correlation between the parameters studied, particularly between the physico-chemical parameters of the soils and between the physico-chemical parameters and the biological diversity indexes. For the mycorrhization parameters, the mycorhization frequencies did not vary from one production areas to another, unlike the intensities, which significantly varied from one production areas to another (2.31% to 24.62%). Finally, this study revealed that the physico-chemical parameters of the soils had an influence on the other parameters studied. Moreover, there were an abundance and a significant diversification of AMFs associated with soybean in the different production areas, which are influenced by certain physico-chemical soil parameters.

Mycorrhizal Association in Wheat Genotypes Submitted to Variable Irrigation in the Brazilian Cerrado

Mycorrhizal association contributes to plant growth, influencing tolerance to abiotic stresses such as water deficit. There is considerable variation in infection by arbuscular mycorrhizal fungi (AMF) in cultivars of the same crop, but there is little information regarding these differences in wheat. The objective of this work was to evaluate the influence of water deficit on the arbuscular mycorrhizal association in wheat genotypes in the Cerrado region and the association between soil attributes and mycorrhizal colonization. The experiment was conducted in a no-till system, using different water regimes. The experimental design was a randomized block with subdivided plots scheme, with 12 treatments and 3 repetitions. The plots consisted of 4 wheat genotypes and the subplots included 3 water regimes. Mycorrhizal colonization, soil microbial biomass carbon, total soil organic carbon, easily extractable glomalin-related soil protein, spore number and AMF species diversity were evaluated. Mycorrhizal colonization was not influenced by wheat genotypes, but it was favored by the higher water regime, being 44.8% higher when compared to the lower water regime. The soil moisture was positively correlated with the soil attributes with the exception of the number of AMF spores. The community of AMF associated with wheat genotypes was similar, comprising of 12 species, predominantly Claroideoglomus etunicatum and Glomus macrocarpum. The low variation among wheat genotypes for AMF diversity suggests no selective influence of the plants on the AMF community in the area of the study. Water regime was shown to be a dominant factor in mycorrhizal association.

Dynamics of arbuscular mycorrhizal fungi and glomalin in the rhizosphere of Gymnocarpos przewalskii in Northwest Desert, China

Relict plants, remnants of Tertiary flora, survived geochronological ages, however, studies intended to ascertain the background of their fungal symbionts are limited. Different from many other relict plants, Gymnocarpos przewalskii Maxim. inhabits arid deserts region, mainly distributed in northwest China. In order to inquire the arbuscular mycorrhizal fungi (AMF) associated to G. przewalskii and their ecological significance in desert ecosystems, the seasonal dynamics of AMF and glomalin were surveyed in Anxi and Minqin in Gansu Province, northwest China. Soil samples in the rhizosphere of G. przewalskii were collected in July, September and December 2019, respectively. In total, 41 and 46 AMF species were identified via morphological techniques in Anxi and Minqin, respectively. Meanwhile, high throughput sequencing (HTS) data diagnosed 29 and 61 AMF OTUs in Anxi and Minqin, respectively. Glomus was the dominant genus in different seasons and locations in both morphological investigation and HTS data. AMF colonization (44.67–75.30%) and spore densities (19–248 per 20 g soil) varied sharply among seasons and locations. AMF colonization and spore densities showed significant positive correlations to most edaphic factors, except soil carbon: nitrogen ratio. Glomalin-related soil protein (GRSP) dramatically contributed to local soil carbon pool (51.54% in Anxi, 40.37% in Minqin), and the GRSP contents in soil were significantly affected by soil properties, season, and location. Random forest analysis indicated that soil humidity and total GRSP were the main factors shaping AMF communities. Our results showed that AMF colonization, spore density, and species diversity were higher and AMF community composition was less variable in Minqin where the soil nutrition levels were lower, which emphasized the necessity of AMF symbiosis for plants in harsh environments. The present research demonstrated the seasonal dynamics of soil AMF communities and glomalin and determined influential environmental factors in desert ecosystems. Our findings provide novel views on desert soil resource management and relict plant protection from an aspect of plant-AMF symbiosis.

Arbuscular mycorrhizal status of Erythrina brucei in different land use types in Ethiopia

Erythrina brucei is a leguminous tree commonly used in agro-forestry practices in southern and southwestern Ethiopia. It has desirable agro-forestry attributes that make it a good candidate for agro-forestry systems. However, there is a scarcity of information regarding species diversity and spore density of arbuscular mycorrhizal fungi (AMF) associated with E. brucei growing in different land use types. Therefore, this study was initiated to determine species diversity and richness in trap cultures of AMF associated with E. brucei growing in different geographic locations in various land use types of Ethiopia. Soil samples were collected from various E. brucei growing areas with different land use patterns. Trap culture was established using a portion of each soil sample by planting E. brucei as the host plant. AMF spore extraction was carried out in field and trap culture soils, and AMF species identification was done using spore morphology. Erythrina brucei root colonization with AMF structures was studied using trap culture, and AMF spore density in both field and trap culture soil samples was determined. A total of 11 AMF genera and 33 AMF species were recovered. The highest number of genera was recovered from forest land use type at Rebu Gebeya, followed by Adiskdam, live fence land use type. Glomus and Acaulospora were the dominant AMF genera covering 73% of the samples and contained 10 and 9 AMF species, respectively. All the soil samples contained indigenous AMF spore populations regardless of their origin and land use types. The highest mean AMF spore density in a field soil sample was recorded at a farmland in Bodite (280 spores 100 g−1 of dry soil), while the lowest was from Hossana (172 spores 100 g−1of dry soil). However, the highest mean AMF spore density in trap culture was detected from a farm land at Humbo (715 spores 100 g−1 of dry soil) and the lowest from Dhakallo (217 spores 100 g−1 of dry soil). Direct extraction of AMF from field soil samples showed lesser AMF spore density compared with trap culture in the same soil sample. All E. brucei root segments were colonized with the AMF structures, and the colonization status ranged from 34.4% to 49.1%. Both geographic location and land use type significantly affected AMF species richness (p < 0.05). Undisturbed land use types were characterized by high species richness. The soil pH and available phosphorus were negatively correlated to AMF spore density (p < 0.05), but AMF root colonization did not show any significant correlation. Moreover, significant correlations were also not observed between spore number and root colonization, and available phosphorus and root length colonization. We conclude that diverse and dominant AMF genera inhabited the rhizosphere of E. brucei, which can be used for the enhancement of host plant growth. To explore AMF species diversity and richness across geographic location and land use types in detail enhanced area coverage and the combination of both direct field soil and trap culture techniques are recommended.

Grazing and mining influence the population of arbuscular mycorrhizal fungi around the opencast coal mine pit.

The influence of grazing and mining on arbuscular mycorrhizal fungi (AMF) species in grassland were studied around the opencast coal mine pit. The two sampling transects had been designed which was located in the grazing area and in the non-grazing area in the grassland on the north side of the opencast coal mining area. Besides, two control points with the direct distance of 8km to the opencast coal mining area have been designed. The two points are located in the inside grassland station and outside the grassland station. We collected 3 replicate rhizosphere soil in every point which is from the two transects. We analyzed the genetic diversity of AMF, measured the chemical properties and enzyme of rhizosphere soil of Cleistogenes squarrosa, and explored their correlations using redundancy analysis. And we identified the factors affecting species diversity of AMF around the mining area. Our results showed that grazing on the grassland around the opencast coal mine will aggravate soil degradation and reduce the species richness and diversity of arbuscular mycorrhizal fungi in rhizosphere soil, which can be a theoretical basis for the scientific management of the grassland around the opencast mining area.