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Mycorrhizal fungi greatly enhanced the ability of plants to take up phosphorus and other nutrients those are relatively immobile and exist in low concentration in the soil solution. Fungi can be important in the uptake of other nutrients by the host plant. Mycorrhizae establish symbiotic relationships with plants and play an essential role in plant growth, disease protection, and overall soil quality. Of the seven types of mycorrhizae described in current scientific literature (arbuscular, ecto, ectendo, arbutoid, monotropoid, ericoid and orchidaceous mycorrhizae), the arbuscular and ectomycorrhizae are the most abundant and widespread. This chapter presents an overview of current knowledge of mycorrhizal interactions, processes, and potential benefits to society. The molecular basis of nutrient exchange between arbuscular mycorrhizal (AM) fungi and host plants is presented; the role of AM fungi in disease protection, alleviation of heavy metal stress and increasing grain production. Most land plants form associations with mycorrhizal fungi. Mycorrhizas are mutualistic associations between fungi and plant roots. They are described as symbiotic because the fungus receives photo synthetically derived carbon compounds and the plant has increased access to mineral nutrients and sometimes water.
Interactions between 42 higher fungi and six strains of Heterobasidion annosum (Fr.) Bref., representing P and S intersterility groups were studied in vitro. Part of the higher fungi was represented by strains of ectomycorrhizal fungi indigenous to old disease centres caused by H. annosum in pine stands. Variation in antagonism to the pathogen was observed both within and between the species. The antagonism was dependent on growth rates of fungi in control. Fungi growing faster displayed a greater ability to arrest the development of the pathogen mycelia. The same tendency was observed in the strains of H. annosum, which generally grew faster and their growth was restricted less than that of higher fungi. Two strains of an ectedomycorrhizal fungus Mrg X, accompanied by a helper bacteria reduced mycelial extension of H. annosum by 72% and 76%. Among ectomycorrhizal fungi, the most effective antagonists were strains of Xerocomus subtomentosus, Amanita muscaria, A. citrina and Laccaria laccata. Three various types of interaction between the studied fungi were observed. Inhibition zone between interacting mycelia appeared often, however the fungi displayed this antagonistic property not to all strains of the pathogen. Although mycelia of H. annosum invaded colonies of the other fungi frequently, in none of the treatments growth of the higher fungus over the opposing colony of the pathogen was observed.
The translocation of zinc, cadmium and lead ions in vegetative mycelia of four species of mycorrhizal fungi was studied. Strong accumulation of zinc, cadmium and lead in aerial mycelium of fungi growing in contaminated medium, and inhibition of the metals' translocation was found. These results were related to species of mycorrhizal fungus and the metal ions that were used for the contaminated medium.
Translocation of selected heavy metals in a mycelium growing in an agar medium supplemented with heavy metals was studied. The study showed that zinc, cadmium and lead were higly accumulated in the mycelium structures and that mycelium actively inhibited metal ion translocation.
A laboratory study was carried out to evaluate the protective role of ectomycorrhizal fungi against contamination of plants growing in soil treated with cadmium at a dose of 150 ^g Cd/ g soil. An alginate- immobilized inoculum of mycorrhizal fungi was used to introduce the fungi to the soil. The impact of fungi was examined in terms of changes in cadmium levels in inoculated and non-inoculated seedlings of Pinus sylvestris L. It was found that the concentration of cadmium in plants inoculated with fungi was signifi­cantly lower than in non-inoculated seedlings. We also observed that the total concentration of cadmium in contaminated soil inoculated with fungi was lower than in non-inoculated soil.
An updated morphology of spores of Septoglomus deserticola, an arbuscular mycorrhizal fungus of the phylum Glomeromycota, is presented based on the original description of the species, only one other its definition recently published and spores produced in pot cultures inoculated with the rhizosphere soil and root fragments of an unrecognized grass colonizing maritime sand dunes of the Hicacos Peninsula, Cuba. Phylogenetic analyses of sequences of the large subunit (LSU) nrDNA region of the Cuban fungus confirmed its affinity with S. deserticola deposited in the International Bank for the Glomeromycota (BEG) and indicated that its closest relatives are S. fuscum and S. xanthium. Phylogenetic analyses of sequences of the small subunit (SSU) nrDNA confirmed the Cuban fungus x S. fuscum x S. xanthium relationship revealed in analyses of the LSU sequences and thereby suggested the Cuban Septoglomus is S. deserticola. However, it was impossible to prove directly the identity of the Cuban fungus and S. deserticola from BEG based on SSU sequences due to the lack of S. deserticola SSU sequences in public databases. In addition, phylogenetic analyses of LSU and SSU sequences confirmed the uniqueness of the recently erected genus Corymbiglomus with the type species C. corymbiforme (formerly Glomus corymbiforme) in the family Diversisporaceae and proved that its LSU sequences group in a clade with LSU sequences of G. globiferum and G. tortuosum. Consequently, the two latter species were transferred to Corymbiglomus and named C. globiferum comb. nov. and C. tortuosum comb. nov., and the definitions of the family Diversisporaceae and the genus Diversispora were emended.
The experiment was conducted in the Experimental Station in Baranowo near Poznań between 2007-2009. The influence of mycorrhizal fungi on the growth and yield of the plum tree cultivar - ' Cacanska Lepotica' and sour cherry tree cultivar - 'Schattenmorelle' was estimated. Three years after planting, the plum trees had bigger vigour of growth, expressed by TCSA, in a combination with mycorrhizal fungi. Sour cherry trees did not differ in growth after the use of mycorrhizal fungi. A higher yield of fruits was harvested from plum and sour cherry trees inoculated with a mycorrhizal fungi. Productivity of mycorrhized trees, calculated according to the cross-sectional area of the trunk, was higher than in the control. The use of mycorrhizal fungi had no influence on fruit mass of the investigated species of fruit trees.
Ectomycorrhizal and saprobic fungi of two industrial wastes in southern Poland (calamine spoil in Bolesław and zinc waste in Chrzanów) were studied. Pine (Pinus sylvestris) accompanied by birch (Betula pendula) were present in the investigated area. Fruitbodies of 68 species were recorded, but only 10 were common to both sites. Mycorrhizal species were the most common group on the zinc waste, whereas saprobic fungi prevailed on the calamine spoil. The differences in species composition between sites might be due to differences in plant cover, but also to the toxicity of the material at the sites. Among mycorrhizal species, members of Cortinariaceae and Tricholomataceae were most frequently recorded. Most ectomycorrhizal species had a broad host range, and only a few species known to be associated exclusively with pine or birch were found. Analysis of ectomycorrhizas by classical and molecular (PCR-RFLP) methods revealed that the fungi forming the most abundant fruitbodies were also present in the form of ectomycorrhizas. A few ascomycete and basidiomycete fungi not recorded as fruitbodies were present as pine symbionts.
The potential of mycorrhization of lettuce in hydroponic conditions was tested in a two-year experiment carried out in the autumn of 2011 and 2012 in an unheated foil tunnel. The experimental factors were as follows: inoculation of plants with arbuscular mycorrhizal fungi (AMF+ or AMF-), concentration of phosphorus in a nutrient solution (10 or 40 mg dm-3) and the type of substrate (rockwool or coconut coir). The inoculation of plants with arbuscular mycorrhizal fungi of the genus Glomus was performed twice, i.e. while sowing seeds and when planting lettuce plants into mats. The impact of the experimental factors on the degree of colonization of lettuce roots by AMF as well as the yield and nutritional status of plants, expressed as the content of macro- and micronutrients, was studied. The mycorrhizal frequency in roots inoculated with AMF reached 51.36%. The nutrient solution concentration of phosphorus and the type of substrate did not have any significant effect on the mycorrhizal frequency. There were no differences in the yield and content of macronutrients in lettuce leaves between plants inoculated and not inoculated with AMF (AMF+, AMF-). Likewise, there were no differences in the yield caused by different phosphorus levels in the nutrient solution or the types of substrate. Plants growing on rockwool accumulated significantly less P, Ca and Mg in comparison to plants growing on coconut coir. Regarding Ca, this effect was especially pronounced in plants receiving the nutrient solution with a higher concentration of P, i.e. 40 mg dm-3. Mycorrhiza had a significant effect on the content of Cu, Mn and Zn in lettuce leaves. Inoculated plants were characterized by a lower content of these micronutries compared to plants grown without AMF. With respect to Mn, this effect was particularly evident in plants grown on rockwool.
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