Arbuscular mycorrhizal fungi

Root and soil samples of three potted or ground-grown cycads (Cycas circinalis, C. revoluta, Zamia sp.) were collected between November 1999 and June 2000 and surveyed for arbuscular mycorrhizal (AM) colonization and spore populations. AM fungi were associated with all root systems and rhizosphere samples examined. Root colonization was of a typical Arum type and AM colonization levels differed significantly between species and between potted and groundgrown cycads. Mycorrhizal colonization levels were inversely related to root hair number and length. Spores of nine morphotypes belonging to three genera (Acaulospora, Glomus, Scutellospora) were extracted from soil. The percentage root length colonized by AM fungi was not related to soil factors, but total AM fungal spore numbers in the rhizosphere soil were inversely related to soil nitrogen and phosphorus levels. AM fungal spore numbers in the soil were linearly related to root length colonized. The co-occurrence of septate non-mycorrhizal fungi was recorded for the first time in cycads. These observations and the relationship between plant mycorrhizal status and soil nutrients are discussed.

Root herbivores and plant mutualists, such as arbuscular mycorrhizal fungi (AMF), have a significant effect on the structure and dynamic of plant communities. Nevertheless, the interactions between the two groups of organisms in natural ecosystems are far from understood. We carried out an inoculation experiment to examine the effect of two root herbivores, Pratylenchus penetrans and P. dunensis (Nematoda), on the composition of the AMF communities associated with two populations of the dune grass Ammophila arenaria. The outcome of the interaction in terms of plant and nematode performance was also analyzed. The total percentage of AMF colonization was not affected by the presence of root-feeders, but they did alter the composition of the AMF communities inside the roots. These changes were dependent on the root-feeder species and the original AMF community: the most severe alterations were observed in the mycorrhizal plants from Wales attacked by P. penetrans. Plant growth was impaired in plants from Wales inoculated with AMF and P. dunensis, which suggests a highly species-specific synergistic interaction with negative consequences for the plant. Root infection by the nematodes was reduced in all mycorrhizal plants when compared to non-mycorrhizal plants. However, a significant reduction of the final number of nematodes was observed only in the mycorrhizal plants from one population.

In this study, we examined the use of the 15N natural abundance method to quantify the percentage N derived from fixation of atmospheric N2 in honeybush (Cyclopia spp.) shrubs and trees in the fynbos, South Africa. Non-fixing shrubs and trees of similar phenology to the Cyclopia species were chosen as reference plants. These reference plants were selected to cover a range of mycorrhizal associations (ericoid mycorrhizal, arbuscular mycorrhizal and non-mycorrhizal). Isotopic analysis revealed a wide range of foliar δ15N values for the reference plants, including many very negative values. The marked differences in δ15N values were defined by the mycorrhizal status of the reference plant species, with the ericoid and arbuscular mycorrhizal plants showing lower foliar δ15N values relative to their non-mycorrhizal counterparts. In contrast, the δ15N values of the N2-fixing Cyclopia species were uniformly clustered around zero, from −0.11‰ to −1.43‰. These findings are consistent with the observation that mycorrhizal fungi discriminate against the heavier 15N isotope during transfer of N from the fungus to the host plant, leaving the latter depleted in 15N (i.e. with a more negative δ15N value). However, a major assumption of the 15N natural abundance method for estimating N2 fixation is that both legume and reference plant should have the same level of fractionation associated with N uptake. But, because mycorrhizal associations may strongly affect the level of fractionation during N uptake and transfer, the test legume should belong to the same mycorrhizal group as the chosen reference plant species. As shown in this study, if the mycorrhizal status of the legume and the reference plant differs, or cannot be assessed, then the 15N natural abundance technique cannot be used to quantitatively estimate N2 fixation.

The maintenance of soil health and productivity is a central aim of sustainable agriculture. Arbuscular mycorrhizal fungi (AMF) are soil biota fundamental for soil fertility and plant nutrition, which may be used in the evaluation of the impact of agronomic practices on soil quality. In the present study we evaluated the influence of three different land uses on AMF populations and correlated glomalin-related soil protein (GRSP) content with AMF biomass parameters, such as spore density and biovolume. Among the differently managed sites -maize monoculture, grassland and poplar grove -maize soil showed the lowest AMF spore number and GRSP content. The same morphological taxa were found in the three sites, except for one additional morphotype in poplar grove. A good correlation between GRSP and spore biovolume was found, suggesting that GRSP may represent a useful biochemical parameter for the assessment of biological soil fertility in sustainable agriculture. #

Two greenhouse experiments were focused on the application of arbuscular mycorrhizal fungi (AMF) and plant growth promoting rhizobacteria (PGPR) in planting of high-biomass crops on reclaimed spoil banks. In the first experiment, we tested the effects of different organic amendments on growth of alfalfa and on the introduced microorganisms. While growth of plants was supported in substrate with compost amendment, mycorrhizal colonization was suppressed. Lignocellulose papermill waste had no negative effects on AMF, but did not positively affect growth of plants. The mixture of these two amendments was found to be optimal in both respects, plant growth and mycorrhizal development. Decreasing doses of this mixture amendment were used in the second experiment, where the effects of microbial inoculation (assumed to compensate for reduced doses of organic matter) on growth of two high-biomass crops, hemp and reed canarygrass, were studied. Plant growth response to microbial inoculation was either positive or negative, depending on the dose of the applied amendment and plant species.

DiVerent arbuscular mycorrhizal fungi (AMF) alter growth and nutrition of a given plant diVerently. Plant gene expression patterns in response to fungal colonization show a certain overlap when colonized by fungi of the Glomeraceae. However, little is known of plant responses to fungi of diVerent fungal taxa, e.g. the Gigasporaceae. We therefore compared the impact of colonization by three taxonomically diVerent AMF species (Glomus intraradices, Glomus mosseae and Scutellospora castanea) on Medicago truncatula at the physiological and transcriptional level using quantitative-PCR. Each AMF developed a speciestypical colonization pattern, with a colonization degree of 60% for G. intraradices and 30% for G. mosseae. Both species developed appressoria, intraradical hyphae, arbuscules and vesicles. S. castanea showed a colonization degree of 10% and developed appressoria, intraradical hyphae, arbuscules and arbusculate coils. All AMF enhanced the plant biomass accumulation and nutritional status although not in correlation with the colonization degree. The expression of 10 mycorrhiza-speciWc or mycorrhiza-associated plant genes could be separated into two clusters. The Wrst cluster, containing arbuscule-induced genes, was highly induced in interactions with G. intraradices and G. mosseae but also slightly induced by S. castanea. The second cluster of genes contained genes that were induced primarily by S. castanea.

The synergetic effect of organic (cow manure) and mineral fertilization on the development arbuscular mycorrhizal (AM) fungi was demonstateded. The length of AM mycelium and sporulation were used as sensitive markers of the physiological state of soil AM fungal population. In manured treatments, both parameters increased in proportion with increasing mineral fertilization. In unmanured soil, the opposite

We studied seasonal variation in population attributes of arbuscular mycorrhizal (AM) fungi over 2 years in four sites of temperate grasslands of the Argentinean Flooding Pampas. The sites represent a wide range of soil conditions, hydrologic gradients, and floristic composition. Lotus glaber, a perennial herbaceous legume naturalised in the Flooding Pampas, was dominant at the four plant community sites. Its roots were highly colonised by AM fungi. Temporal variations in spore density, spore type, AM root colonisation, floristic composition and soil chemical characteristics occurred in each site and were different among sites. The duration of flooding had no effect on spore density but depressed AM root colonisation. Eleven different types of spores were recognized and four were identified. Two species dominated at the four sites: Glomus fasciculatum and Glomus intraradices. Spore density was highest in summer (dry season) and lowest in winter (wet season) with intermediate values in autumn and spring. Colonisation of L. glaber roots was highest in summer or spring and lowest in winter or autumn. The relative density of G. fasciculatum and G. intraradices versus Glomus sp. and Acaulospora sp. had distinctive seasonal peaks. These seasonal peaks occurred at all four sites, suggesting differences among AM fungus species with respect to the seasonality of sporulation. Spore density and AM root colonisation when measured at any one time were poorly related to each other. However, spore density was significantly correlated with root colonisation 3 months before, suggesting that high colonisation in one season precedes high sporulation in the next season.

Soils that were naturally infested with high levels of Verticillium dahliae, the causal agent of wilt disease in strawberry, were amended with fresh and waste lavender, fresh and waste lavandin, hydrosols generated during essential oil production, BioFence TM (a mustard-based defatted seedmeal pellet), or water in microcosms to estimate their efficacy against microslecrotia of the pathogen. Single chemicals and mixtures of the chemicals detected from the substrata were also effective in microcosms. The mixtures were more effective than were the individual chemicals. Microplot evaluation of fresh and waste lavender and lavandin was also made in comparison to BioFence TM and water controls. Lavandin waste was compared to BioFence TM and untreated controls at three sites in field plots that were subsequently planted to strawberry. Disease incidence and severity were measured over time in the field. All of the Lavandula-based materials could be associated with large reductions in the numbers of viable of microsclerotia recovered in all but one experiment with greatest effect in microcosms and smaller effects in microplots and field plots, as could BioFence TM pellets. Due to the high levels of inoculum found at all field sites the reduction in pathogen inoculum density was not necessarily associated with a corresponding reduction in disease incidence, nor with severity as determined by yield. The monoterpenoids associated with the Lavandula spp. are of lower volatility than the isothiocyanates associated with crucifer decomposition and were detected for more than one week after materials were incorporated in soil. This suggests both differences in mode of action and the possibility of combining either the chemicals or the materials that produce them in order to further enhance efficacy. Several non-target effects were considered: numerosity and diversity of bacterial and fungal populations; infection by arbuscular mycorrhizal fungi; and functional diversity of soil microflora. No persistent non-salient effects were detected. (D. Yohalem). colony forming units of the pathogen per gram of soil. Disease incidence and severity in the crop are also used to determine treatment efficacy.

Thirty actinomycete strains were isolated from the rhizosphere of field-grown plants (Trifolium repens L.) and identified by microscopic characteristics, biochemical tests and molecular techniques. The 16S rDNA sequence analysis showed that most of the isolates belong to the Streptomyces genus. These thirty isolates were tested for their capabilities of solubilizing/mineralizing sparingly phosphate sources, N 2 -fixation and/or siderophore production, typical traits of the so-called Plant Growth Promoting Rhizobacteria (PGPR). Phosphate solubilizing ability was widely exhibited by the isolated. All of them produced acid phosphatase and thirteen of them alkaline phosphatase. Ten strains grew in N-free media. Almost all strains produced siderophores, however the production level was in general very low and only the strain Thermobifida MCR24 released considerable amounts of this metabolite. Streptomyces MCR9, Thermobifida MCR24 and Streptomyces MCR26 were selected to test their interactions with arbuscular mycorrhizal (AM) fungi because they produced the highest plant growth beneficial effects among ten isolates preselected as promissory PGPR. The inoculation of AM fungi improved early establishment of MCR9 in clover rhizosphere, and the late establishment of MCR24. The three actinomycete strains improved AM mycelial growth in absence of the test plant, and MCR9 and MCR26 also stimulate AM fungal spore germination. Inoculation of clover plants with either of the selected actinomycetes enhanced plant growth and N acquisition. Co-inoculation of actinomycetes and Glomus mosseae produced synergic benefits on plant growth and MCR9 and MCR24 also on P acquisition. The three selected actinomycetes improve AM formation by clover plants and Glomus mosseae.

Ž . Ž . The arbuscular-mycorrhizal AM colonization patterns of cotton Gossypium hirsutum L. growing under the range of management conditions that are employed for the production of this important crop on the Southern High Plains of Texas was examined in 1991 and 1992. Specifically, the mycorrhizal development of cotton grown under continuous center-pivot irrigation, noncontinuous linear-drive irrigation, continuous center-pivot irrigated cotton planted into terminated winter wheat, supplemental dryland, strict dryland, and supplemental dryland cotton planted into terminated winter wheat was evaluated. During 1991, colonization levels were highest for cotton planted into terminated winter wheat. Furthermore, cotton planted into terminated winter wheat developed more arbuscules and had higher levels of mycorrhizae earlier than any of the other production systems examined. During 1992, at 3 weeks after planting, 5 days of cold, wet weather resulted in almost 100% mortality of cotton not previously planted into terminated winter wheat. Mycorrhizal colonization levels were greater for cotton associated with winter wheat than for cotton grown under conventional practices. The higher colonization levels associated with young cotton plants that were grown with winter wheat as compared with cotton under conventional tillage practices suggests that AM-inoculum levels may have been greater before planting in the cottonq wheat management system for both the 1991 and 1992 studies. Maintenance of a hyphal network for developing cotton seedlings may be crucial for cotton to become colonized rapidly during the seedling stage. Seedling establishment on the Southern High Plains is a critical time for cotton because of abiotic stress from high or low temperatures or inadequate moisture. As a result, any benefit from the symbiosis at this time should have a positive effect on survival and subsequent yields. q 1998 Elsevier Science B.V.

This study investigates an arable field soil with long-term (27 and 28 years) mineral (NPK) and organic (cattle manure, cattle manure with biodynamic preparations) fertilizer amendments at low, medium and high amounts. Arbuscular mycorrhizal (AM) fungi host plant wheat was cultivated in the first vegetation period and non-host amaranth in the second. Phospholipid fatty acids (PLFA) were used to assess soil microbial biomass and community structure. AM fungi were quantified using the marker fatty acid 16:15, with its occurrence in soil PLFAs representing hyphae and in neutral lipid fatty acid (NLFA) spores. Soil microbial biomass was enhanced by the addition of manure and at higher amounts for both fertilizers. AM fungal hyphae and spore biomass responded positively to manure application. The soil microbial community under both crops was dominated by bacteria. The ratio of fungal to bacterial (f/b) PLFAs increased with higher fertilizer amounts but decreased in amaranth plots with the application of manure. Meanwhile the ratio of Gram+/Gram− bacteria indicating environmental conditions (e.g. pH, temperature) was higher in amaranth plots with the addition of manure as compared to wheat plots. Soil PLFA revealed distinct effect of crop type displayed by changes in the occurrence of saturated fatty acids and biomarkers for Gram-negative bacteria and saprotrophic fungi. The latter additionally accounted for the dissimilarity between fertilizer treatments. In sum, the soil PLFA pattern distinctively separated wheat from amaranth plots at 0-5 cm soil depth, indicating a stronger effect of crop rotation and crop identity on soil microorganisms than long-term fertilizer practice.

Fungi share an ancient historical bond with humans which is completely fascinating.
The Strange History of Life
Humans have always been fascinated with life in all its forms, but thousands of years ago, we only classified life on Earth into two categories – plants and animals. We can thank Aristotle for that, and he further divided animals into those with and without blood, as well as those in the land, sea, and air. That rudimentary system remained in place until the 1600s. In the 18th century, Carolus Linnaeus divided life into the kingdoms of animals and plants, and then further began dividing those into different genera and species, which is why we have the two-part naming system in science (Homo sapiens, for example; Homo is the genus and sapiens is the species.

It wasn’t until the middle of the 19th century that single-celled organisms were finally given their due as a separate kingdom of life (Protista). Seventy years later, single-celled organisms were divided into eukaryotes and prokaryotes, so bacteria became the 4th kingdom of life. Although fungi had been recognized as a unique part of the animal kingdom, it was not separated into its own kingdom until 1969. This five-kingdom system remains the most widely accepted format for classifying life on Earth.
All classifications of life until recently, including the expansion from two kingdoms to five, were based on physical observations of how things looked, even under a microscope. This is how the closeness and relationships between species, genera, classes, orders and kingdoms were decided. Given that fact, it comes as no surprise that most people classified fungi as plants for so long. The similarity in appearance is pretty clear, like little red and white trees…

However, thanks to modern technology, the analysis of genetic relationships between species and organisms is now possible, and it shows something very interesting. By examining the genes of different species, both animal and fungi, the mutational changes can be observed, and genealogical relationships can be determined that go back millions of years.

As it turns out, animals and fungi share a common ancestor and branched away from plants at some point about 1.1 billion years ago. It was only later that animals and fungi separated on the genealogical tree of life, making mushrooms more closely related to humans than plants. Most likely, this common ancestor was a single-celled organism that had sperm-like characteristics (like an animal) and then a later developmental stage with a stronger cell wall (fungi).

Are mushrooms vegetables?
Simple answer? No, it’s not a vegetable. Mushrooms are fruiting bodies of macroscopic filamentous fungi. Earlier when mycology (the study of fungi) arose, it was a part of botany. This happened as fungi were considered to be primitive plants. The major difference between a plant (vegetable) and mushroom is how they acquire their food. In the case of plants, they possess chlorophyll and make their food via photosynthesis. Fungi, on the other hand, exist on decaying material in nature. Also the obvious structural differences, such as lack of leaves, roots, and seeds.So fungi now have their own kingdom on the basis of cellular organization.

However, this is the science side of things. Now let us take a look at the other side, the side of food! In terms of food and nutrition, mushrooms are often put in the category of vegetables. The reason for this lies in the nutritional value. Mushrooms and plants have similar nutritional attributes. The nutrients provided by mushroom are spread across various core food groups such as meat and grains. All this has made mushroom a valuable asset in the kitchen both for taste and nutrition.

The Connection Between Mushrooms and Men
Haven’t you ever noticed that eating a perfectly cooked portobello mushroom is closer to eating meat than a salad? Well, that isn’t exactly a scientific explanation of the connection, but this new revelation of our link to fungi does shed some light on the trouble we have with fungal infections in the body. It is notoriously difficult to treat fungal infections, rather than viral and bacterial pathogens, and this close genetic link may explain why.

Fungi and animals are both eukaryotes, with nuclei and other complex structures inside their cell membranes, whereas bacteria are much simpler – composed of just genetic material and a cell wall. Therefore, when we try to fight a bacterial infection, the body is able to easily differentiate and neutralize the threat. Unfortunately, with fungal infections, the body sometimes thinks that the infection is…. us. Drugs that are synthesized to fight the cells of fungal infections may also attack healthy human cells, as there is very little structural difference.

TGX soybean lines were bred at IITA Ibadan for promiscuity with indigenous rhizobia in Nigerian soils. Two cultivars, TGX1456-2E and TGX1660-19F, were tested in a 2-year trial for their response to rhizobial inoculation in five farmers' fields within a 60-km radius of Minna town, in the Southern Guinea savanna zone of Nigeria. Using the ELISA method, the competitiveness and persistence of the two elite strains of rhizobia contained in the inoculant mixture were also studied. There was a close relationship between nodulation and the size of resident rhizobial populations, with wide variation in nodulation across the various sites irrespective of the treatments. Cultivar effect on height and nodule number was significant only in the first cropping season of the trial. The inoculant strains appeared to be less competitive, but more effective, than the indigenous populations. The proportions of the nodules occupied by the inoculant strains were 17% in the first cropping season, and 24% in the second. Inoculation with rhizobia increased the percent arbuscular mycorrhizal infection by an average of 50%. Although grain yield varied between sites, no significant cultivar effect was observed. However, inoculation increased grain yield by 40% in the first cropping season, while no such yield differences occurred in the second season. The proportion of nitrogen derived from N 2 fixation ranged from 27% to 50% in both cropping seasons, and this was dependent on crop management on farmers' fields, rather than any cultivar or inoculation effect.

The aims of this studies were: (i) to examine the influence of heavy metal content (Zn, Cd, Pb, Fe, Cu) and other physico-chemical soil parameters on the level of root colonization of Molinia caerulea and (ii) to relate root colonisation parameters and soil variables to Molinia caerulea abundance in two contrasting habitats (grasslands and heavy metal contaminated sites). The sites differ significantly in terms of bio-available heavy metal contents, particularly Zn (34 times more than grasslands), soil texture, CaCO 3 , organic matter (LOI%), Mg and nitrate content. Principal Component Analysis showed the strong negative correlations between frequency of mycorrhization (F), arbuscular abundance (A%) and intensity of root cortex colonisation (M%) and concentration of bioavailable Zn and Cd. Moreover, no positive correlation between root colonization of Molinia and its abundance was found. The frequency of mycorrhization of root fragments (F%) was only slightly different between these two habitats, whereas the intensity of root cortex colonisation (M%) and relative arbuscular abundance (A%) were significantly lower (3 and 4 times respectively) on the post-industrial sites. The bioavailable Zn content in the substratum of post-industrial sites was strongly negatively correlated with species richness, Shannon diversity index and Evenness. In contrast, these relationships were not statistically significant in grasslands. Based on obtained results we could draw a model of possible relationships between root colonization of Molinia, HM content and Molinia abundance on grasslands and post-industrial sites. Bioavailable Zn content in the soil is a one of main factors influencing the Molinia community diversity. In the grasslands, lower amounts of bioavailable Zn, resulted in higher species richness (R) and species diversity (H) which in turn lead to higher root colonization. On the other hand, on the post-industrial sites, the elevated bioavailable Zn content strongly decreases the plant species richness (R) and species diversity (H) and this caused the decline in root colonization parameters. The low species richness on Zn-polluted sites allowed Molinia to reach higher abundance since the competition with other species is reduced.

The forests of Bhadrachalam, Kothagudem and Paloncha of Khammam District in Andhra Pradesh, India during were surveyed 2007-2010 for micro-and macro-fungi colonizing litter, fruit, bark, humid soils, wood, dung and water, which revealed 131 species associated with diversified substrates of which 96 were micro-fungi and 35 being macro-fungi. Thirty four fungi were cultured, while the remaining could not be cultured. Sixty five species were found colonizing litter, whereas the rest were associated with other habitats of Bhadrachalam forest. Anamorphic fungi dominated the mycofloristics followed by Basidiomycotina. Mastigomycotina, Zygomycotina and Ascomycotina members.

Artemisia annua L. (Asteraceae) is an important medicinal plant whose secondary metabolite artemisinin is used for the treatment of cerebral malaria. A study was undertaken to determine the effect of arbuscular mycorrhizal (AM) fungi, Glomus mosseae, Glomus aggregatum, Glomus fasciculatum, Glomus intraradices and two free living nitrogen fixing bacteria (NFB) (identified as Bacillus subtilis and Stenotrophomonas spp. through 16S rRNA gene sequence analysis), inoculated alone or in combinations on the biomass, nutrient uptake, and content of artemisinin in A. annua under glass house conditions. Various parameters like plant height, total plant biomass, NPK content, leaf yield, mycorrhizal colonization, bacterial population in rhizosphere, phosphatase activity and artemisinin content were determined and found to vary with different treatments. Among all the treatments, plants inoculated with G. mosseae + B. subtilis performed better than any other treatment or uninoculated control plants. The results of the experiment clearly indicated the compatibility and synergy between G. mosseae and B. subtilis and suggested the use of this microbial consortium in A. annua for enhancing growth, biomass yield, and the content and yield of artemisinin.

Lead (Pb) has limited solubility in the soil environment owing to complexation with various soil components. Although total soil Pb concentrations may be high at a given site, the fraction of soluble Pb that plants can extract is very small, which is the major limiting factor for Pb phytoremediation. The symbiotic effect of arbuscular mycorrhizal (AM) fungus, Glomus mosseae was examined on growth and phytoextraction of lead (Pb) by vetiver grass [Chrysopogon zizanioides (L.)]. A hydroponic study, Phase I (0, 1, 2, and 4 mM Pb) was conducted followed by an incubation pot study, Phase II (0, 400, 800, and 1200 mg kg −1 Pb) where vetiver plants were colonized with G. mosseae. The results obtained indicate that plants colonized by the AM fungi not only exhibit better growth (increase in plant biomass), but also significantly increase Pb uptake in root and higher translocation to the shoot at all given treatments. Moreover, plants colonized with AM fungi had higher chlorophyll content and reduced levels of low molecular weight thiols, indicating the ability to better tolerate metal-induced stress. Results from this study indicate that vetiver plants in association with AM fungi can be used for improved phytoextraction of Pb from contaminated soil.

The effect of four fungicides on alkaline phosphatase (ALP) activity in internal and external hyphae of an arbuscular mycorrhizal (AM) fungus was examined. Four-week-old plants were treated with an aqueous solution of the fungicides and then harvested 3 days later. Fungicides were applied at a low and a high level corresponding to 1 and 100 times the recommended field application dose. The

Arbuscular mycorrhizal fungi (AMF) are common organisms in the rhizhosphere of plants in coastal sand dunes where they play a key role in the establishment, growth and survival of plants. This study presents a quantitative analysis of the AMF associated with Ammophila arenaria, the most important sand-fixing species in the foredunes of Europe, in six locations along the western European coast. Spore abundance and root colonisation by AMF were es-. The number of spores varied significantly with time and location. A clear peak of sporulation in autumn was found for three of the northern sites, but no pattern was detected in the southern sites. Root colonisation showed no seasonal pattern, despite differences between sampling times. Both hyphal coils and arbuscules were observed inside the roots, indicating colonisation by more than one AMF species. No correlation was found between root colonisation and spore number, or between AMF abundance and soil fertility. We conclude that: (a) spore production is driven by climatic conditions in the studied northern sites and by plant phenology in the studied southern sites; and that (b) root colonisation is independent of climate, phenology and soil fertility in the studied locations.

Rose-scented geranium (Pelargonium sp.) is a highly valued aromatic crop. Its growth is limited by soil salinity and sodicity stress. Arbuscular mycorrhizal (AM) fungus, phosphate-solubilizing bacteria (PSB), and P fertilizers may enhance the growth and secondary metabolism in geranium plants. In this context, a pot experiment was conducted to study the effects of PSB, AM fungi (Glomus intraradices), and P fertilizer on the yield, chemical composition of essential oil, and mineral element acquisition of geranium. The dry matter yield of shoot and essential oil yield, and mineral element (P, K, Ca, Mg, Na, Fe, Cu, and Zn) uptake in shoot tissues of geranium were significantly increased by the inoculation with AM fungi, co-inoculation with AM fungi and PSB, and P fertilization as compared to control. While the co-inoculation of geranium with AM fungi and PSB significantly enhanced the content of the monoterpenes such as citronellol, geraniol, geranial, and a sesquiterpene (10-epi-γ eudesmol), the P fertilization only enhanced the content of a sesquiterpene, 10-epi-γ eudesmol in the volatile oil. We conclude that the co-inoculation of PSB and AM fungi could be the best natural alternative to phosphate fertilizers to enhance the yield and quality of essential oil from geranium plants grown in sodic soils.

The effect of root-zone flooding on mycorrhizal and non-mycorrhizal peach seedlings growing in a low P medium was examined. Mycorrhizal seedlings showed relatively faster development prior to flooding and recorded significantly higher concentrations of shoot P, K and Zn and biomass yield. Ethanol accumulation was significantly higher in the taproots of non-mycorrhizal as compared to mycorrhizal plants after 3 days of flooding. A more rapid decline in plant health was also observed in non-mycorrhizal as compared to mycorrhizal seedlings. The presence or absence of the fungal partner led to significant difference in the ratio of roots that remained viable after extended flooding. Therefore, it is clear that arbuscular mycorrhizal (AM) infection confers limited tolerance to flooding on peach seedlings. This could be due to improved plant nutrition, the suppression of ethanol accumulation in roots and the extension of the duration of root activity in a flooded environment.

We compared the effect of organic and conventional farming practices on soil microbial dynamics in West Java, Indonesia. A secondary forest was included to obtain natural reference values. On the organic farms, soil fertility is maintained mainly with composted organic matter in contrast to conventional farmers who combine fresh manure and chemical fertilizers, and typically apply large amounts of pesticides. Parameters measured were dehydrogenase, ␤-glucosidase, acid phosphomonoesterase and ␤-glucosaminidase activity, microbial biomass C (MBC) and microbial community composition by phospholipid fatty acid analysis. A strong negative impact of intensive chemical fertilizer and pesticide use on soil enzyme activities was demonstrated. Dehydrogenase and ␤-glucosidase activities were correlated with soil organic matter content and pH. ␤-glucosidase activity under organic management approached that under forest, while MBC and dehydrogenase activity remained higher under forest. The composition of the soil microbial community strongly differed between forest and cultivated soil, a clear difference in composition was also observed between conventional and organic farming. Dehydrogenase activity and C16:1ω5c, marker fatty acid for arbuscular mycorrhizal fungi, appeared to be particularly suited as indicators of the impact of management on soil quality and on the soil microbial community.

The paper presents the results of research on cacti such as Gymnocalycium baldianum, Gymnocalycium mihanovichii, Notocactus eugeniae and Notocactus leninghausii, aimed at improving plant growth and defense against the pathogenic fungus Fusarium sp., through the use of Gigaspora margarita inoculated in the growing medium. Objectives of the work were: i) use Gigaspora margarita to assess if the use of arbuscular mycorrhizae can lead to an increase in the growth rate of Notocactus and Gymnocalycium, plants generally slow in their growth cycle; ii) to evaluate if the use of mycorrhizae can lead to an extension of the duration of the flower, to promote pollination of bees; iii) to assess if the use of Gigaspora Margarita allows greater protection of the roots against the fungus Fusarium sp. which often affects the roots of these cacti. The two experimental groups in cultivation were: i) group without arbuscular michorriza, irrigated with water and substrate previously fertilized; group with Gigaspora Margarita, irrigated with water and substrate previously fertilized. All plants treated with Gigaspora margarita showed a significant increase in plant height and circumference, vegetative and root weight of the plants, number of new suckers, number of flowers and fruits and flower life. In addition, there was significant control of the fungus Fusarium sp. in plants in which Gigaspora margarita was inoculated into the substrate, in fact a reduced infection of the roots due to this pathogen was found. The application of mycorrhiza in the cultivation of plants can guarantee the possibility to obtain a higher quality product, a higher resistance to biotic stress, an increase in growth rate, very interesting aspects in the succulent and cactus plants sector.

The soil environment is interesting and complicated. There are so many interactions taking place in the soil, which determine the properties of soil as a medium for the growth and activities of plants and soil microorganisms. The soil fungi, arbuscular mycorrhiza (AM), are in mutual and beneficial symbiosis with most of the terrestrial plants. AM fungi are continuously interactive with a wide range of soil microorganisms including nonbacterial soil microorganisms, plant growth promoting rhizobacteria, mycorrhiza helper bacteria and deleterious bacteria. Their interactions can have important implications in agriculture. There are some interesting interactions between the AM fungi and soil bacteria including the binding of soil bacteria to the fungal spore, the injection of molecules by bacteria into the fungal spore, the production of volatiles by bacteria and the degradation of fungal cellular wall. Such mechanisms can affect the expression of genes in AM fungi and hence their performance and ecosystem productivity. Hence, consideration of such interactive behavior is of significance. In this review, some of the most important findings regarding the interactions between AM fungi and soil bacteria with some new insights for future research are presented.

Some Acacia mangium Willd. plantations in Asia grow poorly due to low soil fertility and the absence of compatible mycorrhizal fungi. This legume tree can be colonized by arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi but inoculation is not routinely practiced. This study aimed to compare the effectiveness of AM fungi and four isolates of the ECM fungus Pisolithus tinctorius (Pers.) Coker and Couch (Pt) in promoting growth of A. mangium seedlings under glasshouse conditions. AM inoculants were: Glomus etunicatum, G. fasciculatum, G. macrocarpum and Gigaspora margarita and mixed species extracted from rhizosphere soil of a Populus stand in Suwon (AMKFRI), and Carex (AMM6) and Populus (AMM7) growing in mine tailings in Korea. Pisolithus isolates were from Philippines (PtPhil) and Korea (PtKFRI, PtMKACC, PtKACC). Generally, ECM fungi promoted height and diameter growth of A. mangium more than the AM inoculants. The Korean Pisolithus increased plant dry weight by 122-145%, mixed AM inoculants by 61-97%, and Glomus and Gigaspora by 45-72% over the control. PtKACC gave the highest root colonization and promoted the highest growth and concentration of most nutrients. Mycorrhizal root colonization was positively correlated with plant dry weight, Na, Fe and Cu concentrations and N, P, K, Ca, Na, Fe and Cu contents. In conclusion, the results provide strong evidence for benefits of mycorrhizal inoculation on A. mangium seedlings under glasshouse conditions. The Korean Pisolithus isolates (particularly PtKACC), and two AM fungi (AMKFRI and AMM6) are potential mycorrhizal inoculants but their effectiveness and persistence should be determined on degraded lands in tropical countries where A. mangium is being planted for rehabilitation.

A field experiment was conducted to study the effects of inoculation with the arbuscular mycorrhizal fungus Glomus caledonium and/or Rhizobium meliloti on phytoremediation of an agricultural soil contaminated with weathered PCBs by alfalfa grown for 180 days. Planting alfalfa (P), alfalfa inoculated with G. caledonium (P+AM), alfalfa inoculated with R. meliloti (P+R), and alfalfa co-inoculated with R. meliloti and G. caledonium (P+AM+R) decreased significantly initial soil PCB concentrations by 8.1, 12.0, 33.8, and 43.5%, respectively. Inoculation with R. meliloti and/or G. caledonium (P+AM+R) increased the yield of alfalfa, and the accumulation of PCBs in the shoots. Soil microbial counts and the carbon utilization ability of the soil microbial community increased when alfalfa was inoculated with R. meliloti and/or G. caledonium. Results of this field study suggest that synergistic interactions between AMF and Rhizobium may have great potential to enhance phytoremediation by alfalfa of an agricultural soil contaminated with weathered PCBs.

The effects of root colonization by the arbuscular mycorrhizal (AM) fungus Glomus intraradices Schenck and Smith on growth, flower and fruit production, and fruit quality were studied in field-grown tomato plants exposed to varying intensities of drought stress. Inoculated (M+) and non-inoculated (MÀ) tomato seedlings were exposed to varying intensities of drought stress by adjusting irrigation intervals. Mycorrhizal plants had significantly higher uptake of N and P in both roots and shoots regardless of intensities of drought stress. AM inoculation also significantly increased shoot dry matter and the number of flowers and fruits. The fruit yields of M+ plants under severe, moderate, mild drought-stressed conditions were higher than MÀ plants by 24.7%, 23.1%, 16.2% and 12.3%, respectively. Furthermore, M+ plants produced tomato fruits that contain significantly higher quantities of ascorbic acid and total soluble solids (TSS) than MÀ plants. Mycorrhizal effects increased with increasing intensity of drought. The overall results suggest that mycorrhizal colonization affects host plant nutritional status, water stratus and growth under field conditions and thereby alters reproductive behaviour, fruit production and quality of fruits under both well-watered and drought-stressed conditions. #

Singh AK, Jamaluddin (2011) Status and diversity of arbuscular mycorrhizal fungi and its role in natural regeneration on limestone mined spoils. Biodiversitas 12: 107-111. Limestone mined spoils are devoid of adequate population of beneficial microbial flora. Arbuscular mycorrhizal fungi (AMF) are very important constituent of plant- soil-microbe system. In mined spoils the population of AMF is greatly reduced and hence the spoils become very inhospitable for establishment of vegetation. In the present investigation, status of AMF population and its effect on natural regeneration process is studied. It is well known fact that the arbuscular mycorrhizalfungi play very important role in establishment of vegetation in degraded lands. Plantation of seedlings inoculated with arbuscular mycorrhizal fungi provide favorable soil conditions for naturally growing vegetation in the mined overburden spoils. Physico-chemical properties of soil are converted suitable for planted species and thus ...

Field experiment was conducted from December to April 2013 at the Botanical Nursery, University
of  Ibadan,  Nigeria.  The  aim  of  this  study  was  to  investigate  the  interactive  effects  of  arbuscular
mycorrhizal  fungus  (Glomus  mosseae),spent  mushroom  compost  (Pleurotus  pulmonarius)  and
poultry  manure    on  drought  tolerance  and  leaf  curl  resistance  of  okra  (Abelmoschus  esculentus)
genotypes; NG/TO/02/12/156, NG/OA/03/12/157, NG/OA/05/12/159, IJ-OND Okr 1 and IJ-OND
Okr2.  The  treatments  were  laid  out  factorially  in  a  complete  randomized  design  with  three
replications. The result shows that the  effect of replicating  okra accessions and the interactions of
replicate x treatment  were  non- significant (P>0.01) for all  yield traits, drought tolerance and leaf
curl resistance. 
On the other hand, the bio-inoculants treatment was highly resistant to viral leaf curl  and drought,
while  the  effects  of  replicate  and  interactions  of  replicate  x  treatment  were  not  significant.  The
resistance ability to drought effect in second replicate was significantly different from the first and
third replicates which are not significantly different from each other, but the drought tolerance at 2
and 4 WAP  were significantly higher than at 6 WAP. There  was no significant  effect of replicate
and different growth stages on leaf curl infection. The combination of  G. mosseae, P. pulmonarius
and Poultry  manure treated plants for drought tolerance and leaf curl resistance  were significantly
higher  than  the  other  treatments  including  the  control,  while  the  combination  of    P.  pulmonarius
and Poultry manure was the most resistant to leaf curl infection. Therefore, AMF treated plants and
their interactions with other bio-inoculants influenced the drought tolerance and leaf curl resistance
compared to untreated plants.

Over the past few years, micropropagation techniques are being widely used as an important and advantageous tool for rapid propagation of several commercially important varieties of horticultural and forest tree species. Although, this technology has got several successful applications, low survival rates and poor growth while shifting these plantlets to field conditions are the most common problems which hinders its usage for commercial plant production practices. Inoculation of arbuscular mycorrhizal fungi (AMF) to the roots of micropropagated plantlets plays a beneficial role on their post-transplanting performance. This review discusses the multiple roles played by AMF in the establishment of micropropagated plantlets. Different techniques of mycorrhization and the constraints pertaining to the use of these techniques are also discussed. #

Knowledge and conservation of diversity in symbiotic arbuscular mycorrhizal fungi is of crucial importance for their efficient use in environmental conservation and sustainable plant production systems. The recalcitrance of these microorganisms to pure culture, and the absence of information about plasmogamy, karyogamy or meiosis, means that information about the genetical bases of any variations in their population biology ecological specificity or symbiotic activity is generally lacking. A multidisciplinary approach is necessary to identify significant differences between populations, species or isolates. An overview is presented of some of the morphological, biological and molecular aspects of arbuscular mycorrhizal fungi that may contribute to defining and understanding biodiversity in this group of symbiotic microorganisms.

... labile P sources (Bolan, 1991 and Hernández et al., 2000), but other studies demonstrated that mycorrhizal plants obtained P from normally unavailable sources of Pi and Po (Bolan et al., 1987, Jayachandran et al., 1989, Jayachandran et al., 1992, Koide and Kabir, 2000 and ...

The effect of arbuscular mycorrhizal fungi (AMF) on industrial tomato (Lycopersicon esculentum Mill. cv. Isma F1) cultivated in NorthEastern Algeria was evaluated under greenhouse and field conditions in a vertisol soil intended for the cultivation of industrial tomato. In the greenhouse, a commercial AMF inoculum and native fungal isolates consisting of Funneliformis mosseae and Septoglomus constrictum, were added in sterilized or non-sterilized soil and tested for their effects on the growth of tomato. Inoculation with exotic AMF in the commercial inoculum or with native isolates had similar effects in increasing mycorrhizal root colonization rates and tomato growth. In the field, the commercial AMF inoculant was combined with three rates of chemical fertilizer used for the cultivation of industrial tomato (mono-ammonium phosphate, ammonium sulphate and NPK, applied at 0, 50 and 100% of the recommended dose). Introduced AMF significantly improved mycorrhizal root colonization levels, growth and yield as compared to the indigenous AMF alone. In addition, in the presence of the mycorrhizal inoculant, an application of 50% of recommended fertilizer dose provided the same yield as the full fertilizer dose without inoculation. Results clearly show that in this soil, plants needed both fertilization and AMF inoculation to achieve optimal growth and yield, and that the application of AMF can compensate for the reduction in chemical fertilizers, offering a more sustainable farming system that is respectful of the environment.

We developed a reliable, inexpensive, and simple method for staining arbuscular-mycorrhizal fungal colonizations in root tissues. Apart from applications in research, this nontoxic, high-quality staining method also could be of great utility in teaching exercises. After adequate clearing with KOH, an ink-vinegar solution successfully stained all fungal structures, rendering them clearly visible.

A survey of the natural mycorrhizal potential has been carried out in a representative area of a desertified semiarid ecosystem in the southeast of Spain. Many indigenous plants from the field site were mycorrhizal, including the dominant Anthyllis cytisoides, which had high levels of colonization by arbuscular mycorrhizal fungi (AMF). Low numbers of AMF spores were present in the soil, although a range of species, including Scutellospora calospora, Glomus coronatum, Glomus constrictum, and several Acaulospora species, was represented. Soil infectivities, as determined by a soil dilution method, were similar for most plants tested but were significantly lower for Anthyllis cytisoides. Nevertheless, when a less disruptive method to determine soil infectivity was used, the importance of the mycelial network in maintaining the infectivity of soil under perennial shrubs, such as Anthyllis cytisoides, was highlighted. Seasonal variations in the mycorrhizal infectivity showed that it was ...

This article provides an outline of the classification of the kingdom Fungi (including fossil fungi. i.e. dispersed spores, mycelia, sporophores, mycorrhizas). We treat 19 phyla of fungi. These are Aphelidiomycota, and Zoopagomycota. The placement of all fungal genera is provided at the class-, order-and family-level. The described number of species per genus is also given. Notes are provided of taxa for which recent changes or disagreements have been presented. Fungus-like taxa that were traditionally treated as fungi are also incorporated in this outline (i.e. Eumycetozoa, Dictyosteliomycetes, Ceratiomyxomycetes and Myxomycetes). Four new taxa are introduced: Amblyosporida ord. nov. Neopereziida ord. nov. and Ovavesiculida ord. nov. in Rozellomycota, and Protosporangiaceae fam. nov. in Dictyosteliomycetes. Two different classifications (in outline section and in discussion) are provided for Glomeromycota and Leotiomycetes based on recent studies. The phylogenetic reconstruction of a four-gene dataset (18S and 28S rRNA, RPB1, RPB2) of 433 taxa is presented, including all currently described orders of fungi.

The effect of arbuscular mycorrhizal fungi (AMF) on industrial tomato (Lycopersicon esculentum Mill. cv. Isma F1) cultivated in NorthEastern Algeria was evaluated under greenhouse and field conditions in a vertisol soil intended for the cultivation of industrial tomato. In the greenhouse, a commercial AMF inoculum and native fungal isolates consisting of Funneliformis mosseae and Septoglomus constrictum, were added in sterilized or non-sterilized soil and tested for their effects on the growth of tomato. Inoculation with exotic AMF in the commercial inoculum or with native isolates had similar effects in increasing mycorrhizal root colonization rates and tomato growth. In the field, the commercial AMF inoculant was combined with three rates of chemical fertilizer used for the cultivation of industrial tomato (mono-ammonium phosphate, ammonium sulphate and NPK, applied at 0, 50 and 100% of the recommended dose). Introduced AMF significantly improved mycorrhizal root colonization leve...

Arbuscular mycorrhizal (AM) fungi are obligately biotrophic organisms that live symbiotically with the roots of most plants. The establishment of a functional symbiosis between AM fungi and host plants involves a sequence of recognition events leading to the morphological and physiological integration of the two symbionts. The developmental switches in the fungi are triggered by host signals which induce changes in gene expression and a process leading to unequivocal recognition between the two partners of the symbiosis. It has been calculated that about 80% of plant families from all phyla of land plants are hosts of AM fungi. The remaining plant species are either non-mycorrhizal or hosts of mycorrhizas other than the arbuscular type. Non-host plants have been used to obtain information on the factors regulating the development of a functional symbiosis. The aim of this present review is to highlight present-day knowledge of the fungal developmental switches involved in the process of host/nonhost discrimination. The following stages of the life cycle of AM fungi are analysed in detail: spore germination, presymbiotic mycelial growth, differential branching pattern and chemotropism, appressorium formation, root colonization.