Mycorrhizal Fungus Glomus Research Articles

The effect of inoculation with mycorrhizal fungus Glomus caledonium and zinc chelate spraying on the quantity and quality of Satureja bachtiarica Bunge essential oil at full flowering stage

The effect of inoculation with mycorrhizal fungus Glomus caledonium and zinc chelate spraying on the quantity and quality of Satureja bachtiarica Bunge essential oil at full flowering stage

Combined Effects of Microbial Inoculation and Activated Carbon/Biochar on the Accumulation and Transfer of Nutrients and Potentially Toxic Metals in Maize Plants Grown on a Contaminated Soil

ABSTRACT This study was conducted in a greenhouse pot experiment to assess the effects of biochar (BC) or activated carbon (AC) alone or in combination with arbuscular mycorrhizal fungus (AMF) Glomus mosseae or acid-producing bacteria (BA) Bacillus polymyxa on plant growth, EDTA-extractable Cd and Pb, and contents of heavy metals (Cd and Pb) and nutrients (Ca, Mg, K, and P) in maize (Zea mays L.) grown on sewage wastewater contaminated soil. The results showed that most treatments with BC, AC, or its co-application with microbial inoculation led significantly to greater nutrient uptake and promoted growth of maize than non-treated plants. Additionally, the soil additives used decreased the amounts of EDTA-extractable Cd (by 28.7%-100%) and Pb (by 22.8%-94.3%). The applied treatments caused significant decreases in Cd concentrations and the bioconcentration factor (BCF) of Zea mays. The highest shoot Cd reduction was observed for AC (53%), followed by AC+BA (36.9%) > AMF (34.5%) > AC+AMF (28.5) > BA (28.3%) > BC+BA (26.1%) > BC (22.7%). However, more Cd was accumulated in the roots of plants treated with AMF by 63.7% with a lower value of translocation factor (TF) compared to control soil. In contrast, the treatments increased the levels of Pb in the maize plants, and BC coupled with AMF showed the greatest Pb accumulation. It could be concluded that the investigated additives can be applied as immobilizing agents for Cd in the soil but maize plants as phytoextractants for both metals in sewage-contaminated soil are not feasible, as indicated by insufficient phytoextraction efficiency.

Solarized IPM Module for Biocontrol of Root-knot Nematode on Tomato at Nursery Level in District G.B Nagar, Uttar Pradesh

Background: The role of soil solarization in suppression of soil borne pathogens and weeds has been established by several researchers around the globe It involves capturing solar radiations when the soil receives the maximum sunlight in May-June using a polythene mulch. Its effectiveness depends on ambient temperature, duration of the treatments and soil moisture. This not only acts as a soil disinfectant but also as soil decontamination. It includes various changes in the soil like physical, chemical and biological properties. Methods: The field to lab and vice-versal based investigations were carried during 2021-2022 at Amity Centre for Biocontrol and Plant Disease Management, Amity University, Uttar Pradesh, Noida and identified tomato nurseries of district G B Nagar where heavy infestation (10-12 J2/cc soil) of root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood was recorded. The treatments comprised of sustainable components viz. deoiled seed cake of neem, a Arbuscular Mycorrhizal fungus Glomus intraradices and indigenous fungal strain of Trichoderma harzianum, (Th7) alone and together applied for evolving IPM module at solarized and unsolarized sets. Under microplot trials, the entire solarized treatments were carried out measuring 3 × 1 sq. meter each in which one set of all the treatments including control covered with clear transparent polythene sheet (400 ì gauge) for solarization. The treatments were replicated thrice in randomized block design. Result: The observations of solarized and unsolarized treatments clearly revealed that the soil solarization in treatments where the sun radiant energy was trapped by 400 µ transparent polysheets significantly reduced the root knot nematode Meloidogyne incognita population both in root and soil in comparison to unsolarized treatments where no solar energy trapping was done. The combined application of locally isolated Trichoderma harzianum (Th7) and VA mycorrhiza, Glomus intraredices enhanced germination and plant growth in nurseries. In the present investigation, the solarized IPM module- 4 comprising of other sustainable components viz. neem oil-seed cake, T. harzianum (Th-7) and Arbuscular Mycorrhizal (AM) fungus G. intraredices is proved to be an ideal one in root-knot nematode pest management in tomato nurseries.

Glomus fasciculatum an arbuscular mycorrhizal fungus alleviate the adverse effects of lead, arsenic, nickel, and improves growth parameters of Monarda citriodora Cerv.ex Lag (lemon beebalm)

Heavy metals induce negative impacts on plants, however, the symbiotic association of an arbuscular mycorrhizal fungi (AMF) Glomus fasciculatum offers an effective tolerance response. The aim of the present study was to investigate the impact of Lead (Pb), Arsenic (As), and Nickel (Ni) with and without the application of AMF on one of the important medicinal and aromatic plants Monarda citriodora Cerv. ex Lag (lemon beebalm). The metal concentrations mixed in soil were: Pb (25 and 50 mg/kg), As (15 and 30 mg/kg) and Ni (20 and 40 mg/kg) along with constant dose of AMF (2.7 g/kg soil) while untreated plants were taken for comparison. Results showed that higher concentrations of Pb (50 mg/kg), As (30 mg/kg), and Ni (40 mg/kg) decreased the plant height by 48%, 6%, and 7% respectively, and the number of branches by 19%, 10%, and 25% respectively when compared with controls. The biomass and nutrient contents were also altered in the plants that received Pb, As, and Ni. However, the application of AMF has improved the overall growth and development of plants but not more than the control. Furthermore, higher concentrations of Pb (50 mg/kg), As (30 mg/kg), and Ni (40 mg/kg) increased total phenolics by 975%, 375%, and 373% respectively, flavonoids by 149%, 136%, and 127% respectively, proline content by 656%, 225%, and 472% respectively, and radical scavenging activity by 124%, 146%, and 157% respectively, when compared with control. Additionally, higher concentrations of Pb, As, and Ni treatments also decreased the AMF colonization rate in roots by 37%, 35%, and 49% when compared with their lower concentrations. The elevation of secondary metabolites and scavenging activity in response to metal toxicity indicates that M. citriodora is a rich source of natural antioxidants. So, future strategies are required to study valuable antioxidant compounds present in this plant.

Macro and Microelements in Leaves of ‘Meredith’ Peach Cultivar Supplied with Biochar, Organic and Beneficial Biofertilizer Combinations

The content of macro and microelements in the leaves of peach trees treated with biochar, organic fertilization and microorganisms in the field experiment was tested. The experiment was carried out in accordance with the integrated fruit production methods at the NIHR Experimental Orchard in Dąbrowice, from 2015 to 2017. The trees were grafted on P. persica Mandżurska rootstock and planted in the spring of 2013. In 2014, the following products were applied around the trees and mixed into the topsoil: biochar at a dose of 1.6 kg/tree (2000 kg/ha); biochar at a dose of 1.6 kg/tree used together with microorganisms—bacteria Pseudomonas fluorescens, Pantoea and arbuscular mycorrhizal fungi—Glomus caledonium, Glomus intraradices and Glomus coronatum; biochar at a dose of 1.6 kg/tree applied together with Florovit NPK organic fertilizer at a dose of 0.2 kg/tree; Florovit NPK; microorganisms—bacteria Pseudomonas fluorescens, Pantoea and arbuscular mycorrhizal fungi—Glomus caledonium, Glomus intraradices and Glomus coronatum; Florovit NPK organic fertilizer with the same microorganisms; and an untreated control. The average results showed that, compared to the control, the biochar increased the nitrogen content in the leaves by 6%. All experimental combinations increased the content of P and K in the leaves. The most effective at increasing the content of phosphorus in leaves—by 48%—was Florovit. The greatest increase in potassium was after the use of biochar with Florovit—by 38%. The magnesium content ranged from 0.49 to 0.59 g/100 g DW. The highest content of Mg was found in the leaves after the application of biochar with Florovit, and the lowest after the use of biochar alone. The leaves of the trees fertilized with the Florovit organic fertilizer had the lowest calcium content, while the highest calcium content was found in combination with trees treated with biochar only. The use of biochar alone did not increase the content of boron in the leaves compared to the control. In all other combinations, a higher amount of boron was found. The highest—18% more than the control of this microelement had leaves where biochar and Florovit were used. Trees treated with biochar and microorganisms accumulated the least copper in the leaves, while the highest content of this element was found in the combination where biochar fertilization was applied together with Florovit. Lower iron concentrations in peach leaves were found as a result of applying microorganisms, microorganisms with the organic fertilizer and biochar, relative to organic fertilization and the control combination. Trees where only microorganisms were applied to the soil had the least manganese and zinc in the leaves. The accumulation of manganese in the leaves was most favored by fertilization with biochar together with microorganisms, and the zinc content was the highest after the use of biochar alone. In general, studies have shown that a small dose of biochar alone or biochar together with organic fertilizer is a very effective method of feeding peach trees. More research is needed on the use of microorganisms and methods of their application with various products used in orchard fertilization.

A comparative study between some biocontrol agents and the nematicide furfural on growth of tomato plants and pathogenesis of meloidogyne javanica under green-house condition

An experiment was conducted to study the effect of three fungal biocontrol agents along with G.mosseae and nematicide furfural against root knot nematode Meloidogyne javanica infecting tomato plants(Lycopersicon esculentum) under greenhouse condition. Bioagents are Paecilomyces lilacinus, Trichoderma harzianum , T. viride and mycorrhizal fungus Glomus mosseae which were compared with the nematicide furfural . The furfural compound was the best treatment in promoting plant growth and reduction the number of root galls/plant . The result showed that the T. harzianum was the best biocontrol agent in increasing shoot length and root length 16.2 % , 26.1% respectively .The P. lilacinus was the best biocontrol agent in reduction root galling (57.53%). Combination of biocotrol agents with G. mosseae and furfural was the least effective treatment in promoting plant growth and the reduction of root galling was 31.43%.

Soil drenching and foliar spray with bioagents for reducing wheat leaf diseases under natural field conditions

Foliar diseases, like powdery mildew, septoria leaf blotch (SLB) and stem rust, affect wheat plants causing severe yield losses. Biofertilizers Pseudomonas fluorescens Migula (NRC2041) and Bacillus subtilis Ehrenberg (NRC313) or the arbuscular mycorrhizal fungi Glomus mosseae Tul. & C. Tul. (NRC212A) and G. fasciculatum Tul. & C. Tul. (NRC212B) were used for soil treatment followed by foliar spray with Trichoderma harzianum or P. fluorescens to manage severity of wheat foliar diseases under field conditions for two successive growing seasons. Under field conditions, at all soil drench and foliar application treatments, Sids 14 was the most sensitive cultivar for high disease severity followed by Misr 2 and Giza 168. Also, the obtained results showed that the most effective treatments were soil drench with mycorrhizae followed by foliar spray with either T. harzianum or P. fluorescens. Meanwhile, the fungicide Amistar showed a superior reduction in disease severity compared to other applied treatments. In addition, the increased yield was correlated to the decreased severity of the recorded diseases. The present study suggests using bioagents for reducing the severity of wheat leaf diseases and increasing the grain yield under field conditions.

Phytoremediation Potential of Arbuscular Mycorrhizal Fungi and Berseem in Soil Irrigated with Industrial Wastewater

This article describes a new idea about industrial pollution abatement through berseem ( Trifolium alexandrinum L.) using arbuscular mycorrhizal fungi (AMF) Glomus Spp. as an accelerating agent. For this purpose, berseem plant was grown on soil irrigated with industrial wastewater in pots. Three cuttings of plants were obtained at different intervals. At each cut, plant biomass, plant height, and rate of mycorrhizal infection were recorded and plant tissues (roots, stems and leaves) were analyzed to determine the concentrations of Cd, Cr, Pb, and Zn as indicators. The results showed that the biomass of the roots, stems, and leaves of the inoculated plants was higher than that of the un-inoculated plants. The height of inoculated plants was higher compared with that of uninoculated plants. The mycorrhizal infection rate was recorded highest at the third cut. Heavy metals in plants were within permissible limits for crops irrigated with wastewater) at each cutting. With inoculation, Zn and Cr concentrations in roots and leaves increased and Pb and Cd enhanced in roots but reduced in leaves as compared to un-inoculated plants, indicating that metals accumulated more in roots due to inoculation. The effectiveness can be confirmed by calculating the difference between the inoculated and non-inoculated plants. The new results showed that AMF inoculation promoted plant biomass and height, reduced metal transfer in leaves and stems, and to roots. This research confirmed that the procedure can be used for protecting plants from toxicity. Keywords: arbuscular mycorrhizal fungi, heavy metals, biomass, mycorrhizal infection rate, berseem. https://doi.org/10.55463/issn.1674-2974.50.4.6

Arbuscular mycorrhizal fungi enhance disease resistance of Salvia miltiorrhiza to Fusarium wilt.

Salvia miltiorrhiza Bunge (Danshen in Chinese) is vulnerable to Fusarium wilt, which severely affects the quality of the crude drug. Mycorrhizal colonization enhances resistance to fungal pathogens in many plant species. In this study, pre-inoculation of S. miltiorrhiza with the arbuscular mycorrhizal fungi (AMF) Glomus versiforme significantly alleviated Fusarium wilt caused by Fusarium oxysporum. Mycorrhizal colonization protected S. miltiorrhiza from pathogen infection, thereby preventing a loss of biomass and photosynthesis. There were greater defense responses induced by pathogen infection in AMF pre-inoculated plants than those in non-treated plants. AMF pre-inoculation resulted in systemic responses upon pathogen inoculation, including significant increases in the protein content and activities of phenylalanine ammonia-lyase (PAL), chitinase, and β-1,3-glucanase in S. miltiorrhiza roots. In addition, mycorrhizal pre-inoculation caused upregulation of defense-related genes, and jasmonic acid (JA) and salicylic acid (SA) signaling pathway genes after pathogen infection. The above findings indicate that mycorrhizal colonization enhances S. miltiorrhiza resistance against F. oxysporum infection by enhancing photosynthesis, root structure, and inducing the expression of defense enzymes and defense-related genes on the other hand.

Response of Capsicum annuum L. Seedlings Raised in Pro Trays to Inoculation with AM Fungus Glomus bagyarajii and K Solubilizing Bacterium Frateuria aurantia

Raising vegetable seedlings in pro trays is becoming an innovative approach to producing quality seedlings in horticulture. The present investigation was conducted to evaluate the effect of arbuscular mycorrhizal fungus (AMF) Glomus bagyarajii and potassium (K) solubilizing bacterium Frateuria aurantia singly and together in enhancing the growth of capsicum seedlings raised in pro trays under polyhouse conditions. Different growth parameters such as shoot and root length, total seedling length, stem diameter, dry weight of seedlings, biovolume index, plant strength, vigour index, macro and micronutrient uptake, mycorrhizal root colonization, and the population of F. aurantia in the root zone soil were monitored. Significantly higher shoot length, root length, stem diameter, and biovolume index were recorded in the treatments inoculated with G. bagyarajii alone, followed by F. aurantia alone. Most of the plant growth parameters were significantly less in the dual inoculated treatment with G. bagyarajii + F. aurantia compared to single inoculation with either of them. This brings out the negative influence of the two inoculants on each other leading to a reduced effect on plant growth.

Reducing Pratylenchus Population in Coffee Seedling with Mycorrhizal Fungi and Mycorrhiza Helper Bacteria

The attack of Pratylenchus coffeae nematode on coffee seedlings can limit coffee growth. The use of beneficial microbes as biofertilizer and bioprotectant is suggested to reduce the nematode attack on coffee seedlings and improve growth. A greenhouse experiment was conducted to observe the effect of arbuscular mycorrhizal fungi (AMF) Glomus spp. and mycorrhiza helper bacteria (MHB) P. diminuta and B. subtilis on coffee seedling growth and P. coffeae populations in the soil and roots. The experiment was set up in a randomized block design with five treatments and three replications. The coffee seedlings were grown in potting soil and inoculated with Glomus spp. combined with 20 g or 30 g of MHB solid inoculant. Seedlings were grown in the greenhouse for 10 weeks. The experiment verified that AMF inoculation combined with MHB did not affect the plant height, leaf number, or plant dry weight but decreased the P. coffeae population in the soil and roots of the seedlings. Inoculation of 20 g of MHB solid inoculant with AMF was more effective in reducing nematode population in soil and roots than 30 g of MHB. This experiment verified that Glomus spp., as well as P. diminuta and B. subtilis enable the control of P. coffeae in coffee seedlings.

Management of chromium(VI)-contaminated soils through synergistic application of vermicompost, chromate reducing rhizobacteria and Arbuscular mycorrhizal fungi (AMF) reduced plant toxicity and improved yield attributes in Ocimum basilicum L.

An integrated approach involving vermicompost, chromate reducing bacteria and AMF was tested to manage the toxic impacts of Cr(VI) on Ocimum basilicum as a model plant. Pot experiments were conducted on O. basilicum plants in an artificially Cr(VI)-contaminated soil in two phases of experiment as bioinoculants experiment and vermicompost experiment. In the first phase of the bioinoculants experiment the series of gradient concentrations of Cr(VI) (0, 25, 50 and 100 mg kg–1 in soil) were evaluated with previously isolated four efficient Cr(VI)-reducing rhizo-bacterial strains (Bacillus Cereus strain SUCR 44, BC; Microbacterium sp. strain SUCR 140, MB; Bacillus thuringiensis strain SUCR186, BT; and Bacillus subtilis strain SUCR188; BS) along with Arbuscular Mycorrhizal Fungus—Glomus fasciculatum (GF) in alone and in co-inoculation form. In the second experiment (vermicompost) the best performing strain (MB) was tested alone or in combination with GF along with different doses of vermicompost. It was observed that vermicompost by itself could be useful in decreasing the bioavailable Cr(VI), uptake of Cr besides improving the nutritional status of plants. The vermicompost also played an important and indirect role and improved herb yield by supporting the multiplication of MB (Microbacterium sp.), an efficient chromate reducing rhizobacteria, that further decreased the bioavailable and toxic form of Cr and improved population and colonization of GF too. The translocation of Cr(VI) was averted through improved colonization of GF, also prevented higher accumulation of Cr in aerial parts (leafy herb) of O. basilicum.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00203-022-03230-z.

Physiological response of chickpea (Cicer arietinum L.) in symbiosis with arbuscular mycorrhizal fungi under salinity conditions

Objective. Evaluate the effect of salinity due to NaCl on physiological variables of chickpea plants using native strains of arbuscular mycorrhizal fungi (AMF) Glomus cubensis and Rhizoglomus irregulare during the pre-flowering stage. Design/methodology/approach. The research was carried out under controlled weather conditions using the chickpea variety N-29 as an experimental model. The treatments consisted on the combination of four salinity levels: 0, 25, 50 and 75 mM NaCl (variation source A) and AMF (variation source B) in three levels. In total there were 12 treatments with six repetitions, which were distributed in a completely randomized experimental design. The evaluated variables were number of green and dry leaves, dry biomass per organ (leaves, root and stem), net assimilation rate (NAR), relative growth rate (RGR) and leaf area ratio (LAR). Results. The green leaves, the NAR and the dry biomass from roots and leaves, were the variables with the greatest response in the 50 mM NaCl + R. irregulare treatment, with an average increase of 15% with respect to the rest of the treatments. Limitations/implications. A decrease on the evaluated variables was observed due to the salinity effect; however, chickpea plants subjected to NaCl 50 mM inoculated with R. irregulare were less affected by salt stress. Findings/conclusions. The R. irregulare strain was found to contribute more than the G. cubensis to the mitigation of the adverse effects from the salinity factor.

Morphological characterization and response of red flower rag leaf (Crassocephalum crepidioides Benth S. Moore) to organic and inorganic fertilizers and arbuscular mycorrhizal fungus

Red flower rag leaf (Crassocephalum crepidioides) is one of the underutilized vegetables consumed globally. Pot trials were conducted to characterize 15 morphologically distinct accessions of C. crepidioides and assess the effects of treatment combinations of eggshell, NPK 15:15:15, poultry manure and arbuscular mycorrhizal fungus(Glomus mosseae) as soil amendments on growth and yield-related characters of C. crepidioides. Thereafter, 48 seedlings of the best performing accession were transplanted into perforated polythene bags filled with 7 kg of heat-sterilized soil. The experiment was laid out in a completely randomized design with three replicates. Treatment combinations were incorporated into in the polythene bags 1 week after transplanting, while control plants received no amendments. The results showed that accession NH/GKB-15 had the highest plant height (29.83 cm), stem length (27.67 cm), number of leaves (15) and length of internode at node 3 (1.13 cm) and node 4 (1.17 cm). The growth and yield characters of this best performing accession (NH/GKB-15) in response to soil amendments showed that poultry manure produced the tallest plants (55.17 cm), longest and widest stems (48.35 and 0.66 cm), longest and widest leaves (16.39 and 6.26 cm, respectively), and higher number of inflorescence (2.13). With NPK 15:15:15 the seedlings did not survive. Poultry manure should therefore be utilized for better plant nutrition and faster growth of C. crepidioides seedlings as well as for safer consumption of the leafy vegetable.

Effect of mycorrhizal fungi in combination with botanicals, fungicides and bio-agents in ameliorating Fusarium wilt management in chickpea (Cicer arietinum)

Fusarium wilt incited by Fusarium oxysporum f. sp. ciceris causes substantial economic losses in chickpea. Tostudy the effect of mycorrhizal inoculation in combination with different bio-agents, fungicides and botanicals onthe Fusarium wilt incidence and yield of chickpea, field trials were conducted during 2019–20 at the research field ofCCS Haryana Agricultural University, Hisar. Mycorrhizal fungi were found to be beneficial in alleviating chickpeawilt incidence and upsurging the yield components of chickpea. The mycorrhizal fungus Glomus mosseae performed better than Glomus hoi, evincing the importance of mycorrhizal species. Seed soaking provided more disease control in comparison to soil drenching of plant extracts, bio-agents and fungicides except azoxystrobin 23% SC in variety JG 62 in which mode of application of fungicide had no significant effect on disease incidence. Amongst mycorrhiza × treatment interaction, carbendazim 50% WP provided utmost disease control (>80%) in the soil pre-inoculated with G. mosseae and Glomus hoi, followed by azoxystrobin 23% SC and Trichoderma viride, while aqueous extract of datura leaves was the least effective in both chickpea varieties JG 62 and C 235.

Mycorrhizal fungi Glomus spp. propagation in zeolite enriched with mycorrhiza helper bacteria for controlling nematode in coffee

Arbuscular mycorrhizal fungi (AMF) play a role in suppressing the nematode Pratylenchus coffeae. Mycorrhizal helper bacteria (MHB) can increase the effectiveness of AMF to control the diseases. The experimental purpose was to increase the spore population of AMF Glomus spp. in zeolite-based formulation inoculated with liquid consortia of Pseudomonas diminuta and Bacillus subtilis as MHB. The experimental design was a completely random design with six treatments consisted of 106, 107, 108, and 109 CFU/mL MHB liquid inoculants. The control treatments were water and 2% molasses. All treatments were replicated four times. A total of 300 mL/pot Liquid inoculant of MHB have been inoculated a three day before transplanting the maize seedling to the Zeolite inoculated with Glomus spp. in the pot. One month after MHB inoculation, Glomus formulation in Zeolite with different levels of MHB increased the degree of infection. Three months after MHB inoculation, spore content in Zeolite increased. The density of P. diminuta and B. subtilis in zeolite-based mycorrhizal inoculant increased at the end of the experiment. Liquid inoculant MHB contained 108 CFU/mL enhanced spora number fourth times compared to the control. This experiment suggests that P. diminuta and B. subtilis were effective to increase the spore density of AMF inoculant.

Application of biological products at cultivation of garden pea Pisum sativum l.

The possibilities of using the biological products “Trichodermine” (Trichoderma viride Pers ex Fr.), “Gliocladine” (Gliocladium virens Miller et al.) and the mycorrhizal activator “Rhizo VAM Basic” (Glomus intraradices Schenck&Smith) for control of fungal diseases in garden pea and and their impact on the biometric indicators of young plants were studied. Biological preparations based on antagonistic fungi Trichoderma viride and Gliocladium virens improve the phytosanitary condition of the plants, the mycorrhizal fungus Glomus intraradices stimulates the formation of the root system and tuber formation, but has a weak fungicidal effect against Fusarium wilt in this culture. The experiment was performed on an artificial infectious background by Fusarium oxysporum Schlecht. f. sp. pisi (Hal.) Raillo, isolated from diseased plants. The effect of application of the biological products“Trichodermine” and “Gliocladine” is 34-68%, from “Rhizo VAM Basic” - 8% compared to the infected control. The combined application of biological preparations with fungicidal and mycorrhizal action significantly protects the crop from infection with the causative agent of Fusarium wilt of garden pea.

Effect of single or dual inoculation of the arbuscular mycorrhizal fungus Glomus mosseae and root-nodulating rhizobacteria on reproduction of the burrowing nematode Radopholus similis on non-leguminous and leguminous banana intercrops

The bio-protective effect of either single or dual mycorrhizal (AMF) and rhizobial colonisation of the roots of non-leguminous and leguminous banana intercrops differing in host response to Radopholus similis on the reproduction of this important migratory endoparasitic nematode was examined. Included in the study were sorgho-Sudan grass (good R. similis host), sweet potato and common bean (intermediate hosts), soybean and sunn hemp (poor hosts), and marigold (non-host). Significant plant growth-promoting effect of single AMF and rhizobial colonisation in the good and intermediate R. similis hosts sorgho-Sudangrass (AMF) and common bean (AMF and rhizobium), respectively, was observed whereas this plant growth-promoting effect was absent in the other intercrops with the exception of sunn hemp with significant plant growth-promoting effect of AMF colonisation on fresh root weight. An additive plant growth-promoting effect of dual AMF and rhizobial colonisation (on fresh shoot weight) was only observed in the poor R. similis host soybean. Single AMF and rhizobial colonisation also resulted in a significant bio-protective effect against R. similis in sorgho-Sudangrass (AMF), sweet potato cv. Inzovu (AMF) and common bean (AMF and rhizobium). The growth-promoting and bio-protective effects of AMF colonisation were clearly present in the good and intermediate R. similis hosts with moderate to high relative mycorrhizal dependency (RMD) values ranging from 47% (sorgho-Sudangrass) to 65% (common bean) but absent in the intermediate R. similis host sweet potato, which had a negative RMD value, and in the poor and non- R. similis hosts. Overall, no suppressive effect of R. similis infection on AMF and rhizobial colonisation was observed except in soybean and sunn hemp in which AMF colonisation was significantly reduced.

Study of symbiotic nitrogen fixation of chickpea (Cicer arietinum L.) in the Oryol region

Modern agriculture tends to reduce chemogenic loads on the environment and becomes more environmentally oriented. In this regard, increasing the yield of agricultural crops through the use of useful soil microflora is an urgent direction in research. In the field conditions of the Oryol region, the features of the formation and operation of symbiotic systems of 13 chickpea varieties under mono - and double inoculation with different strains of nitrogen-fixing bacteria Mesorhizobium ciceri and a soil-root mixture containing a mix of arbuscular mycorrhizal fungi Glomus spp were studied. The use of microbiological drugs had a positive effect on the growth and development of most chickpea varieties, which contributed to a more intensive accumulation of green mass of plants, led to an increase in the duration of the growing season by 1…7 days compared to the control. At the same time, the plants exceeded the control by 0.5…23.4% in height. There was an increase in the weight of dry plants by 0.7…70.1%, the number of seeds per plant by 0.3…69.1%, the weight of seeds per plant by 0.6…71.4%, and the weight of 1000 seeds by 0.4…36.9%. It was found that the most powerful and active symbiotic apparatus in chickpeas is formed during the flowering period – the beginning of bean formation. The maximum number of nodules was formed in the Avatar variety in the variant with mono inoculation of Mesorhizobium ciceri strain 065 and in the Krasnokutsky 123 variety in the variant with Mesorhizobium ciceri strains 527 and 522. The highest values of nitrogenase activity (109.23…155.79 mg N2/plant h) were recorded in the varieties Avatar, Krasnokutsky 123 and Kostyuzhansky 27 in the variants with double inoculation.

Physiological and Productive Response of Two Varieties of Tomato (<i>Solanum lycopersicon</i>) to the Application of <i>Glomus iranicum</i> in the Region of Extremadura

Two varieties of tomato plants, H 1015 (1) and H 3402 (2) from two adjoining commercial farms located in San Benito, Extremadura and cultivated in the same soil and fertirrigation conditions, were inoculated with the arbuscular mycorrhizal fungus Glomus iranicum variety Tenuihypharum, (AMF) from the commercial product Mycogrowth. The applied treatments to the plants were: control 1, AMF 1, control 2 and AMF 2. The physiological indicators and productive responses of the plants from the four treatments were studied. The percentage of mycorrhization, soil moisture, the growth of dry aerial biomass, leaf water potential (Ψ leaf), stomatal conductance (gs), photosynthetic rate (Pn) and performance of its components rate were evaluated 81 days after transplantation. The (Ψ leaf) and (Pn) were measured twice (10.00 and 13.00 h). The results showed that symbiosis between tomato plants and the AMF was successful. Plants of both varieties treated with AMF, had better physiological performance, increased leaf water potential, increased gas exchange (stomatal conductance and photosynthetic rate), and showed improvements in growth, quality and productivity at plot level. The positive effects of this fungus show that it could result of great importance for reducing the use of chemical fertilizers, at least partially, in the future.