Diversity Of AM Fungi Research Articles

Diversification of crops and intensification of canola impact the diversity, community structure, and productivity in successive crop systems: A study on arbuscular mycorrhizal fungal communities in roots and rhizosphere

The widespread cultivation of canola, conventionally still considered a non-host plant for AM fungi, coupled with its increasing frequency in crop rotations, raises concerns about its impacts on soil microbial diversity and overall crop productivity. The main objective of this study is to assess the influence of different crop succession systems, incorporating canola, on AM fungal diversity and community structure in both the roots and in the rhizosphere, as well as on productivity of each crop present within the succession. Doubling the frequency of canola occurrence in a 4-year crop succession did not reduce the productivity of the other crops in the succession, nor did it result in a decrease in AM fungal biodiversity in the roots or rhizosphere of these crops. Interestingly, the diversity of AM fungi was higher in canola roots compared to wheat roots, indicating that canola might serve as a rudimentary host of AM fungi. The succession systems did, however, alter the AM fungal community structure in both roots and rhizosphere environments, exhibiting positive or negative correlations with crop productivity. This suggests that a simple modification of the cropping system could potentially be employed to manipulate root or rhizosphere microbiomes. Results of this study add to the growing body of evidences that plants that were thought to be non-AM fungi host, such as plants from the Brassicaceae family, could in fact interact with AM fungi.

Diversity of arbuscular mycorrhizal fungi in the rhizosphere of Angelica glauca and Valeriana jatamansi in NW Himalaya, India

Abstract. Tapwal A, Kumar A, Sharma S. 2023. Diversity of arbuscular mycorrhizal fungi in the rhizosphere of Angelica glauca and Valeriana jatamansi in NW Himalaya, India. Asian J For 7: 89-97. The diverse mycorrhizal association helps to conserve plant biodiversity, ecosystem function, and the accumulation of pharmaceutically important compounds in medicinal plants. Climate change may have an impact on plant diversity as well as on associated microbiota. The mycorrhizal association and diversity of Arbuscular Mycorrhizal Fungi (AMF) in the rhizosphere of two important medicinal plants of the North-Western (NW) Himalayas were explored during different seasons in two distant locations. The endomycorrhizal association in Angelica glauca Edgew. and Valeriana jatamansi Jones was confirmed by morpho-anatomical characterization of the roots. Microsclerotia, vesicles, and intracellular hyphal coils were found in the roots of both medicinal plant species. The research revealed 24 AMF representing eight genera in the rhizosphere of A. glauca and 19 AMF representing seven genera in the rhizosphere of V. jatamansi. The AMF colonization varied between 55.63-86.34% in the roots of A. glauca and 55.23-78.74% in V. jatamansi. The Spore Density (SD) in the rhizosphere soil of selected medicinal plants was highest during the winter season. The rhizosphere soil of A. glauca exhibited a rich diversity of AM fungi during the rainy season. On the other hand, in various seasons and locations, the maximum diversity of AM fungi was observed during the summer season in V. jatamansi. The genera–Glomus and Acaulospora had the highest species in both study sites.

Diverisity of AM Fungi in Rhizosphere of Calotropis gigantea in Indian Thar Desert

A study was conducted to access the diversity of AM Fungi and relationship of Calotropis gigantea in Indian Thar Desert. For this purpose, soil samples along with the plant root were collected from different areas of Indian Thar Desert. The survey of AM fungi associated with Calotropis gigantea in Indian Thar Desert revealed that eleven AM fungi commonly occur in the rhizosphere viz., Acaulospora laevis, Acaulospora morrawae, Gigaspora gigangea, Gigaspora margarita, Glomus aggregatum, Glomus constrictum, Glomus deserticola, Glomus fasciculatum, Glomus macrocarpum, Scutellospora calospora and Scutellospora nigra. It was found the 4 genera of AM Fungi are distributed in these soils. However, relative abundance and qualitative distribution of AM genera was found to vary from place to place.

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.

Seasonal variations of arbuscular mycorrhizal fungal community in greenhouse soil under different rotation systems.

Soil samples were collected at the fallow period, flowering stage, and fruiting stage of tomato under tomato-melon (TM) and tomato-bean (TB) systems. Illumina MiSeq high-throughput pyrosequencing was performed to analyze the differences in AM fungal community between the two rotation systems. We further analyzed the key factors driving the changes in AM fungal diversity and community composition. Results showed that rotation with legume significantly altered the α-diversity of AM fungi. Shannon diversity and Pielou evenness of AM fungi under the TB system were 24.9% and 24.0% lower than that under TM system, respectively. Compared to the fallow period, richness, Shannon diversity, and phylogenetic diversity of AM fungi at the tomato flowering and fruiting stages decreased significantly by 55.6%-67.5%, 49.6%-51.5%, and 21.4%-23.7%, respectively. Rotation with legume (the TB system) promoted the relative abundance of Glomus in all the three sampling times, but reduced the relative abundance of Paraglomus and Archaeospora at the flowering and fruiting stages. Claroideoglomus was more abundant in soils under the TM system than that under the TB system at the fallow period, but the pattern was the opposite at the flowering stage. Ambispora, Diversispora, and Scutellospora were detected only in soil under the TB system. Results of permutational multivariate analysis of variance (PERMANOVA) and non-metric multidimensional scaling (NMDS) analysis showed that both rotation system and growing stage significantly affected the structure of AM fungal community. Soil moisture, pH, and Olsen-P were the predominant factors controlling the variations in the diversity and composition of AM fungal community. Results of structural equation modeling (SEM) further indicated that rotation system and growing stage affected the variations in AM fungal diversity and community structure indirectly via changing soil pH.

Illumina-based identification of arbuscular mycorrhizal fungi from Karachay-Cherkessia soils for development of bio-fertilizers

The aim of the study was to investigate the species diversity of AM fungi in different parts of the North Caucasus, biodiversity hotspot, the center of the world’s biological diversity. Samples were taken from 5 locations (stationary trial plots, STPs) in different ecosystems and at various altitudes. Identification was performed using sequencing for ITS1 and ITS2 regions, amplified with universal primers, Illumina MiSeq was employed. 19 genera of AM fungi were found on all STPs. The work did not reveal a correlation between the altitude and the species composition of AM fungi. At the same time, it should be assumed that a correlation could be found between the biodiversity of AM fungi and the type of ecosystem, which should be done in the future. The study shows it is necessary to use an analysis for both ITS regions, since the data obtained for each ITS region differ and complement each other. Analysis for the ITS2 region revealed 1.3 times more virtual taxa than for the ITS1, while the number of OTUs identified per species was similar for both regions. The highest biodiversity of AM fungi was found in STP #3 (with meadow flora). Only 4 species (Rhizophagus irregularis, R. intraradices, Paraglomus laccatum, and Claroideoglomus claroideum) were found on all five analyzed STPs. We found unexpectedly that with such a high biodiversity among the identified fungi, no different species were found in the Paraglomus genus, all the sequences of Paraglomus belonged to Paraglomus laccatum, whereas at least 9 species are distinguished in the genus by morphology. Further research will allow us to identify new strains of AM fungi, the efficiency of which may be higher than already studied ones. In the future this will make it possible to create more effective microbial biofertilizers for agriculture.

Drought intensify the effects of warming on root-colonizing arbuscular mycorrhizal fungal community in subtropical Chinese fir plantation

Despite the important linkages of AM fungi with plants, the studies regarding the responses of AM fungal community to warming and drought have lagged behind that of the aboveground plants. In this study, we investigated the impacts of four years of warming and drought on the taxonomic and phylogenetic composition of root-colonizing AM fungal communities in a manipulated field experiment in a five year old Chinese fir plantation. The phylogenetic patterns were also used to evaluate the ecological processes structuring AM fungal communities. Results indicated that the diversity of AM fungi remained relatively stable after the four years of warming and drought. Variations in the taxonomic and phylogenetic composition of AM fungal community were recorded under warming but not drought treatments. Under drought conditions, warming made the largest pronounced effects on AM fungal community composition. A decrease in the Glomeraceae abundance and increase in the Gigasporaceae abundance were found to primarily contribute to the differences in the AM fungal community composition between control and warming treatments. In addition, AM fungal communities were phylogenetically clustered across all experimental treatments, suggesting that environmental filtering such as selection by host plants was the primary ecological process structuring the root-associated AM fungal community assembly. Overall, these findings supported that warming exerted significant effects on the root-colonizing AM fungal communities, especially under drought conditions, but not changed the ecological processes responsible for the assembly of AM fungal communities in the subtropical region.

Arbuscular mycorrhizal fungi in roots and soil respond differently to biotic and abiotic factors in the Serengeti.

This study explores the relationships of AM fungal abundance and diversity with biotic (host plant, ungulate grazing) and abiotic (soil properties, precipitation) factors in the Serengeti National Park, Tanzania. Soil and root samples were collected from grazed and ungrazed plots at seven sites across steep soil fertility and precipitation gradients. AM fungal abundance in the soil was estimated from the density of spores and the concentration of a fatty acid biomarker. Diversity of AM fungi in roots and soils was measured using DNA sequencing and spore identification. AM fungal abundance in soil decreased with grazing and precipitation and increased with soil phosphorus. The community composition of AM fungal DNA in roots and soils differed. Root samples had more AM fungal indicator species associated with biotic factors (host plant species and grazing), and soil samples had more indicator species associated with particular sample sites. These findings suggest that regional edaphic conditions shape the site-level species pool from which plant species actively select root-colonizing fungal assemblages modified by grazing. Combining multiple measurements of AM fungal abundance and community composition provides the most informed assessment of the structure of mycorrhizal fungal communities in natural ecosystems.

Biodiversity of arbuscular mycorrhizal fungi associated with selected medicinal plants of Hamirpur district of Himachal Pradesh, India

The present investigation was focused on exploration of biodiversity of Arbuscular mycorrhizal fungi (AMF) associated with different medicinal plants. Twenty-two medicinal plants belonging to 14 families were analyzed for AMF colonization. The plant roots and their respective rhizosphereic soil samples were collected from different localities of hamirpur district, himachal pardesh for AMF analysis and spore assessment per 50gm of soil sample of soil. The results revealed that number of AM spores in the rhizosphere of plant was not related to percent of AM root colonization. Highest per cent of root colonization was reported in Ricinus communis (86.5±4.68 %) and Achyranthes aspera lacks colonization. Highest number of AM spore was found in rhizosperic soil sample of Mimosa pudica (177.4±4.306) and least number of spores in Datura stramonium (47.53±2.76). Fourty three AM species belonging to five genera i.e. Glomus, Acaulospora, Gigaspora, Entrophospora and Sclerocystis were isolated during investigation. Maximum AM spore diversity was observed in Mentha viridis followed by Catharanthus roseus and least diversity related to Datura stramonium. The study confirmed that diversity of AM fungi varies with plant to plant.

Diversity of AM fungi in certain ornamental plants growing at different sites of Allahabad, Uttar Pradesh, India.

Use of flowers in Indian cultural and religious purposes has a central place in people’s daily lifestyle. In India, increasing demand and supply of various types of flowers opened a vast scope for the production of flowers. In the present study, five important ornamental plants were collected from five different sites of Allahabad, Uttar Pradesh for the survey purpose to investigate arbuscular mycorrhizal status and diversity. All the ornamental plant species were found to be mycorrhizal but the magnitude of infection varied with the sites, plants species as well as stages of plant growth. A total of 38 species belonging to four different genera of AM fungi were isolated. Glomus was recorded as the most dominant genus with 22 species, followed by Acaulospora with 14 species, sporocarp of Sclerocystis sinuosa and Scutellospora with a single unidentified species. Study of Shannon Weiner diversity index, Species richness and Species evenness also carried out in all the five sites. Diversity of all the sites showed less variation indicating a stable and a diverse fungal community.

Management of the biological diversity of AM fungi by combination of host plant succession and integrity of extraradical mycelium

As functional diversity influences the benefits conferred on host plants by arbuscular mycorrhizal fungi (AMF) and large scale commercial inoculation is currently impracticable, strategies are required to manage communities of indigenous AMF associated with different hosts within agricultural cropping systems. In a non-sterilized soil, using 454 pyrosequencing of the LSU-D2 rDNA gene, host plant AMF diversity was assessed following successions of different plant species, grown with or without prior soil disturbance. Diversity present in the roots of two species of the Fabaceae (Ornithopus compressus and Trifolium subterraneum) was compared with those of two species of Poaceae (Lolium rigidum and Triticum aestivum). When spores and colonised root fragments formed were the main propagules source (disturbed soil), the communities of AMF present in the two legumes were clearly different from those of the two members of the Poaceae but were similar for plants within each family, consistent with there being preferential symbioses existing within an AMF population for host classes. Significantly, wheat grown in undisturbed soil immediately after the legume O. compressus acquired a mycorrhizal fungal community closely related to that of the previous host plant, and different to that found when the soil was disturbed or not cropped prior to the growth of the wheat. Parallel effects were seen in the succession from L. rigidum to T. subterraneum, indicating that these effects are not unique to the legume-wheat sequence. These results also suggest that, under no-till cropping, selected cover crops or crops in rotation could help build mycorrhizal communities that function throughout a sequence of several main crops.

Interaction of soil microbes with mycorrhizal fungi in tomato

In this study, the interaction of soil microbes with mycorrhizal fungi (MF) was performed to understand the effect on tomato. A pot and a field experiment were employed to investigate the impact of soil microbes i.e. Fusarium oxysporum f. sp. lycopersici, Trichoderma harzianum, Aspergillus niger and Rhizobium leguminosarum, on AM fungi in pots and field studies. The soils without microbes which treated controls with or without mycorrhizal inoculation were also included. Plant growth and root colonisation were measured 36, 75 and 120 days post inoculation (dpi) in the both pot experiment and field study. Soil microbes’ effects on the growth behaviour of the tomato plant were determined via the shoot and root weight. R. leguminosarum and A. niger did not affect the colonisation ability much, but F. oxysporum f. sp. lycopersici and T. harzianum resulted in the inhibition of AM fungal colonisation in both pot and field studies. Our study provides evidence for the effects of soil microbes on the diversity of AM fungi and their effect on the tomato plants. The higher concentrations of phosphorus and of proteins in the root tissues, previously colonised with AM fungi, point out their effect as biofertilizers, according to the concept of sustainable agriculture.

Differences in the AMF diversity in soil and roots between two annual and perennial gramineous plants co-occurring in a Mediterranean, semiarid degraded area

Aims In the present study, we analysed the diversity of indigenous arbuscular mycorrhizal fungi (AMF) colonising both the roots and rhizosphere soil of an annual herbaceous species, Bromus rubens, and a perennial herbaceous species, Brachypodium retusum, co-occurring in the same Mediterranean, semiarid degraded area. The intention was to study whether these two species promoted the diversity of AM fungi in their rhizospheres differently and to ascertain whether the AMF community harboured by an annual plant species differed from that harboured by a perennial species when both grew in the same place.

Diversity of AM fungi in some tree species from dry land area of central Maharashtra (India)

AM symbiosis reducing damage caused by soilborne pathogen and abiotic stresses and its protection is modulated by soil and other environmental conditions. Drought stress is one of the abiotic stresses in most areas of central Maharashtra (India) and lots of tree species survive in this drought-prone area; the present investigation deals with qualitative and quantitative distribution of AM fungi in rhizosphere soil of three tree species from three localities in the dry land area of central Maharashtra, the mycorrhizal population with respect to its variation in the month of May to October and to study the physicochemical properties of rhizospheric soil. The spore population was very high in the months of June to September in all three localities studied. The extent of colonisation by AM fungi was moderately high (70–100%). During this season there was positive correlation between AM colonisation and spore population in these months because of moderate rainfall. The species of Gigaspora and Acaulospora were dominant in Acacia arabica and Prosopis specigera rhizospheric soil, whereas the species of Glomus and Sclerocystis were dominant in association with Azadirachta indica. Thirteen dominant AM fungal species were observed in test plants. The uneven distribution of AM fungi in different localities during different seasons may be attributed to the differential physicochemical properties of soil.

Plant type differently promote the arbuscular mycorrhizal fungi biodiversity in the rhizosphere after revegetation of a degraded, semiarid land

It is suggested that the diversity of arbuscular mycorrhizal fungi (AMF) and their association with distinct plants species are crucial in the early stages of revegetation procedures since the AMF roots colonisation plays an important role improving plant establishment and growth. We carried out a study where we analyse the AMF community composition in the roots of Ephedra fragilis, Rhamnus lycioides, Pistacia lentiscus and Retama sphaerocarpa fourteen months after revegetation in a Mediterranean semiarid degraded area of southeast Spain in order to verify whether different plant species can variably promote the diversity of AM fungi in their rhizospheres after planted. We analysed a portion of approximately 795 bases pairs of the small-subunit ribosomal DNA by means of nested PCR, cloning, sequencing and phylogenetic analyses. Eight fungal sequence types belonging to Glomus group A and B and to the genus Paraglomus were identified. The different plant species had different AM fungal community composition. Thus, R. lycioides harboured the highest number of four fungal sequence types while from E. fragilis only two types could be characterized that were specific for this plant species. P. lentiscus and R. sphaerocarpa harboured each one three sequence types and two of them were shared. All AMF sequence types were found in the natural soil. These results show that one effective way of restoring degraded lands is to increase the number of plant species used, which would increase the AMF diversity in the soil and thus the below-ground, positive interactions.

Assessing the diversity of AM fungi in arid gypsophilous plant communities

In the present study, we used PCR-Single-Stranded Conformation Polymorphism (SSCP) techniques to analyse arbuscular mycorrhizal fungi (AMF) communities in four sites within a 10 km(2) gypsum area in Southern Spain. Four common plant species from these ecosystems were selected. The AM fungal small-subunit (SSU) rRNA genes were subjected to PCR, cloning, SSCP analysis, sequencing and phylogenetic analyses. A total of 1443 SSU rRNA sequences were analysed, for 21 AM fungal types: 19 belonged to the genus Glomus, 1 to the genus Diversispora and 1 to the Scutellospora. Four sequence groups were identified, which showed high similarity to sequences of known glomalean species or isolates: Glo G18 to Glomus constrictum, Glo G1 to Glomus intraradices, Glo G16 to Glomus clarum, Scut to Scutellospora dipurpurescens and Div to one new genus in the family Diversisporaceae identified recently as Otospora bareai. There were three sequence groups that received strong support in the phylogenetic analysis, and did not seem to be related to any sequences of AM fungi in culture or previously found in the database; thus, they could be novel taxa within the genus Glomus: Glo G4, Glo G2 and Glo G14. We have detected the presence of both generalist and potential specialist AMF in gypsum ecosystems. The AMF communities were different in the plant studied suggesting some degree of preference in the interactions between these symbionts.