Mycorrhiza

Global scenario currently is reduced agricultural cultivable areas, increase in population growth, hence the farmer’s aims to increase the productivity by applying abundant inorganic fertilizer without considering the status of Soil health. Soil health normally refers to an ecological equilibrium balance and function of soil and its vital capacity to have maintain well-balanced ecosystem with abundant biodiversity above and below the surface and productivity. The understanding and interpretation of soil health from the perspectives of soil functions, processes, and properties is summarized. Also the good soil is normally defined by the content of Soil organic carbon content, thereby strongly it impacts soil quality, functionality and health. Incorporating different approaches which tend to maximize the physical, chemical and biological property shall be encountered and practiced. This chapter gives the broad outline over soil health and key indicators, management practices, Sustainable soil management and its approaches. Enhancing and sustaining soil health is also pertinent to advancing Sustainable Development Goals of the U.N. such as alleviating poverty, reducing hunger, improving health, and promoting economic development.

Intensive agriculture, while increasing food production, has caused second generation problems in respect of nutrient imbalance including greater mining of soil nutrients to the extent of 10 million tons every year depleting soil fertility, emerging deficiencies of secondary and micronutrients, decline of water table and its quality of water, decreasing organic carbon content, and overall deterioration in soil health. Indian soils not only show deficiency in both primary nutrients (Nitrogen, Phosphorous and Potassium) but also of secondary nutrients (Sulphur, Calcium and Magnesium) and micronutrients (Boron, Zinc, Copper, and Iron etc. (Ministry of Agriculture, 2015). Improved grain production to meet the food demand of an increasing population has been highly dependent on chemical fertilizer input based on the traditionally assumed notion of ‘high input, high output’, However, crop yield has not increased proportionally with growing fertiliser inputs in recent decades, resulting in low nutrient use efficiency and increased environmental concerns which results in overuse of fertilizers ignores the biological potential of roots or rhizosphere for efficient mobilization and acquisition of soil nutrient. The plant roots and rhizosphere interaction in the Rhizosphere region where plant releases exudates from roots which act as chemical signals. This involves in Nutrient cycling and nutrient transformation. The rhizosphere offers a potential solution to combat these deficiencies and improve soil fertility. Also signalling between plant and rhizosphere is very rich and complex micro biome diversity which they undergoes both interspecies and intraspecies signalling.

Mycoheterotrophic plants have lost the ability to photosynthesize and obtain essential mineral and organic nutrients from associated soil fungi. Despite involving radical changes in life history traits and ecological requirements, the transition from autotrophy to mycoheterotrophy has occurred independently in many major lineages of land plants, most frequently in Orchidaceae. Yet the molecular mechanisms underlying this shift are still poorly understood. A comparison of the transcriptomes of Epipogium aphyllum and Neottia nidus-avis, two completely mycoheterotrophic orchids, to other autotrophic and mycoheterotrophic orchids showed the unexpected retention of several genes associated with photosynthetic activities. In addition to these selected retentions, the analysis of their expression profiles showed that many orthologs had inverted underground/aboveground expression ratios compared to autotrophic species. Fatty acid and amino acid biosynthesis as well as primary cell wall metabolism were among the pathways most impacted by this expression reprogramming. Our study suggests that the shift in nutritional mode from autotrophy to mycoheterotrophy remodeled the architecture of the plant metabolism but was associated primarily with function losses rather than metabolic innovations.

We translate Noël Bernard's discovery of orchid symbiotic germination discovered on Neottia nidus-avis, as published in the May 1899 issue of the Comptes rendus hebdomadaires des séances de l'Académie des sciences. In his note, Bernard (1874Bernard ( -1911) ) establishes the need for a fungus, which is also forming mycorrhizae in adults, for seeds germination. We provide illustrations reproduced from his later works, and summaries of the French text he cited. In our annotations, we show how early this discovery was done in Bernard's career, and insist on the scientific framework at the end of the nineteenth century, where orchid germination was mysterious and the need for vicinity of parents was not fully understood. We comment the text of Bernard on the basis of the most recent knowledge on Neottia nidus-avis and on orchid mycorrhizal fungi. Introducing his following papers, we finally discuss the emergence of the concept of peloton digestion, and how Bernard's work quickly paved the way to a general understanding of mycoheterotrophic germination in orchids and beyond.

Mycoheterotrophic plants have lost the ability to photosynthesize and obtain essential mineral and organic nutrients from associated soil fungi. Despite involving radical changes in life history traits and ecological requirements, the transition from autotrophy to mycoheterotrophy has occurred independently in many major lineages of land plants, most frequently in Orchidaceae. Yet the molecular mechanisms underlying this shift are still poorly understood. A comparison of the transcriptomes of Epipogium aphyllum and Neottia nidus-avis, two completely mycoheterotrophic orchids, to other autotrophic and mycoheterotrophic orchids showed the unexpected retention of several genes associated with photosynthetic activities. In addition to these selected retentions, the analysis of their expression profiles showed that many orthologs had inverted underground/aboveground expression ratios compared to autotrophic species. Fatty acid and amino acid biosynthesis as well as primary cell wall meta...

Some mixotrophic plants from temperate forests use the mycorrhizal fungi colonizing their roots as a carbon source to supplement their photosynthesis. These fungi are also mycorrhizal on surrounding trees, from which they transfer carbon to mixotrophic plants. These plants are thus reputed difficult to transplant, even when their protection requires it. Here, we take profit of a successful ex situ pot cultivation over 1 to 3 years of the mixotrophic orchid Epipacis helleborine to investigate its mycorrhizal and nutrition status. Firstly, compared with surrounding autotrophic plants, it did not display the higher N content and higher isotopic (13C and 15N) abundance that normally feature mixotrophic orchids because they incorporate N-, 13C-, and 15N-rich fungal biomass. Second, fungal barcoding by next-generation sequencing revealed that the proportion of ectomycorrhizal fungi (expressed as percentage of the total number of either reads or operational taxonomic units) was unusually l...

We translate Noël Bernard's discovery of orchid symbiotic germination discovered on Neottia nidus-avis, as published in the May 1899 issue of the Comptes rendus hebdomadaires des séances de l'Académie des sciences. In his note, Bernard (1874Bernard ( -1911) ) establishes the need for a fungus, which is also forming mycorrhizae in adults, for seeds germination. We provide illustrations reproduced from his later works, and summaries of the French text he cited. In our annotations, we show how early this discovery was done in Bernard's career, and insist on the scientific framework at the end of the nineteenth century, where orchid germination was mysterious and the need for vicinity of parents was not fully understood. We comment the text of Bernard on the basis of the most recent knowledge on Neottia nidus-avis and on orchid mycorrhizal fungi. Introducing his following papers, we finally discuss the emergence of the concept of peloton digestion, and how Bernard's work quickly paved the way to a general understanding of mycoheterotrophic germination in orchids and beyond.

RESUMO: Este trabalho teve como objetivo avaliar o efeito de dois compostos orgânicos produzidos com resíduo de sisal, esterco e farinha de rocha, e da inoculação com fungos micorrízicos no crescimento e nutrição de mudas de sisal. O experimento foi instalado em delineamento de blocos ao acaso com cinco repetições, em esquema fatorial 2 x 2 + 2, sendo dois compostos orgânicos e duas espécies fúngicas (Claroideoglomus etunicatum e Paraglomus occultum), mais um tratamento sem inoculação micorrízica e outro sem os compostos orgânicos. A aplicação isolada do composto com 1 0% esterco, 1 0% farinha de rocha e 80% resíduo de sisal, ou do fungo C. etunicatum promoveram aumento na altura (46,6% e 26,4%, respectivamente) e na produção de biomassa (304,9% e 51 ,1 % respectivamente) das mudas. Os compostos estimularam a colonização radicular das mudas pelo fungo C. etunicatum, mas não apresentaram efeito sobre a esporulação desta espécie. Não houve efeito dos compostos sobre a esporulação e colonização radicular pelo fungo P. occultum. A aplicação isolada ou a combinação dos compostos e das espécies fungicas promoveram incrementos significativos nos teores de nutrientes das mudas.

Arbuscular mycorrhizal (AM) fungi can increase plant uptake of nutrients especially relatively immobile elements such as P, Zn and Cu and consequently, improve plant growth and yield. The study was conducted to identify native AM strains, multiply and test their effects in reduction of P fertilizer brinjal production. Rhizosphere soils and roots of and brinjal were collected from each of four AEZs, viz. AEZ-9 (RARS, Jamalpur), AEZ-11 (RARS, Jashore), AEZ-25 (ARS, Bogura) and AEZ-28 (BARI, Joydebpur) in 2014-2015. Characterization and identification of arbuscular mycorrhizal strains was studied in the microbiology laboratory of Bangladesh Agricultural Research Institute (BARI). Nine AM strains were identified in brinjal Glomus geosporum, G. mosseae, G. fasciculatum, Acaulospora dilatata, A. mellea, A. morrowiae, Entrophospora infrequens, Sclerocystis coremioides and Gigaspora margarita were identified in brinjal. The collected mycorrhizal strains were maintained with trap crop sorghu...

Non-ectomycorrhizal fungi that associate with typical ectomycorrhizae often remain hidden, and their localization inside ectomycorrhizal (ECM) roots has remained uncharacterized. In this study, the fungal community associated with the ectomycorrhizae of Castanopsis cuspidata was investigated using a culture-dependent isolation technique. Additionally, the species composition and localization were determined using molecular techniques. The results of the isolation and identification of fungal species revealed the predominance of a few species belonging to the order Helotiales. Furthermore, the fungal community structures were significantly different depending on the taxa of the ectomycorrhiza-forming fungi. A taxon-specific probe was developed to analyze the localization of one dominant Hyaloscyphaceae (Helotiales) species in ECM tissues by in situ hybridization. Hybridization signals were detected on the surface of the fungal mantle and around the ECM fungal cells within the mantle....

El extremo sur de Sudamérica, Patagonia, se destaca por los interesantes patrones de distribución que exhiben los representantes de su flora y fauna local. Los estudios biogeográficos muestran que numerosos linajes de esta biota están relacionados con otras áreas del Hemisferio Sur, como Australia y Nueva Zelanda. Asimismo, esta región constituye un importante centro de endemismos, en parte,como consecuencia del aislamiento geoclimático impuesto por la Diagonal Árida.Polystichum Roth (Dryopteridaceae) es uno de los géneros con representantes endémicos en la Patagonia. Los Polystichum Sudamericanos Australes comprenden siete especies que se distribuyen en los bosques subantárticos y en islas del Atlántico Sur y en el Archipiélago Juan Fernández. Las diferencias en atributos morfológicos sugieren que este grupo no estaría estrechamente emparentadocon los otros Polystichum de Sudamérica. Debido a su compleja taxonomía y su distribución restringida, estos helechos generan preguntas sobr...

The present study was conducted during the 2016-2017 at University of Sulaimani, College of Agricultural Sciences. This investigation aimed to study the effect of humic acid (foliar application) with three levels; 2.5, 3.5 and 4.5 ml/L and three levels of (soil application) ; 1.5, 2.5 and 3.5 ml/L, compared with the control (spray with water only) on growth and yield components of broccoli (Brassica oleracea L. var. corato). After 2 weeks from transplanting, the humic acid was added four times to the plants. The experimental design was used is Random Complete Block Design (RCBD), with three replicates was applied and the means compared according to Dunken at 0.05 level. The obtained results showed that soil application in the rate of (1.5 ml/L) achieved the highest results of Plant height (53 cm), fresh weight of main head (403.5 gm) and total yield (50 ton/ha). On the other hand, the highest value of the main head diameter was obtained by foliar application of 2.5 ml/L. In addition, the highest value of TSS was recorded when humic acid as a foliar spray at a rate of 3.5 ml/L, while the amount of NPK were not significantly affected by applications of different doses of humic acid. These results imply that soil application of humic acid at the rate of 1.5 ml/L could be recommended to use in the agricultural field for producing optimum yields.

This study was aimed to examine the effect of different cultivation techniques on growth and yield components of an amphibious promising line of red rice by conducting a field experiment on ricefield in Beleke village of West Lombok (Indonesia) from May to August 2018. The experiment was arranged according to Split Plot Design with two factors and three blocks. The main plot factor was cultivation technique (T) with three treatments (T1= conventional; T2= aerobic rice systems (ARS) on raised-beds; T3= ARS intercropped with peanuts), and the sub-plot factor was rice row patterns (P) with three treatments (P1= normal or single-row; P2= double-row; P3= triple-row). In the intercropping raised-beds, peanut seeds were relay-planted between single-, double-, or triple-row of rice at two weeks after seeding rice. Results indicated that red rice plants grown under aerobic irrigation systems on raised-beds, especially those intercropped with peanuts, showed higher growth performance and yiel...

This research aimed to examine the effect of application of Petroganik and bio-fertilizer containing arbuscular mycorrhizal fungi (AMF) on yield performance of black rice grown under three different techniques of growing rice, i.e. conventional, irrigated aerobic rice system (ARS) and ARS intercropped with peanut under row proportion of 2:2. The experiment was conducted in Dasan Tebu (West Lombok, Indonesia) from May to August 2019, which was also used as a demonstration plot to show the different performance of back rice under non-conventional techniques of growing rice to the local farmers. The experiment was designed according to Split Plot Design with four blocks and two treatment factors, i.e. techniques of growing rice (T1= conventional, T2= aerobic irrigation system (ARS) on raised-beds, T3= ARS on raised-beds intercropping with peanut) as the main-plot factor, and application of organic and bio-fertilizer (F1= NPK fertilizer only, F2= NPK + Petroganik, F3= NPK + Petroganik +...

This study aims to determine the effect of aerobic rice system, either with or without organic fertilization and intercropping with soybean, on growth and yield of two genotypes of red rice. The experiment was arranged in Completely Randomized Design testing three treatment factors: rice cultivation techniques (T1= conventional, T2= aerobic rice intercropped with soybean, T3= aerobic rice without intercropping); organic fertilization (B0= without, B1= with organic fertilization using “Bokashi”); red rice genotypes (V1= Inpago Unram 1, V2= Amp-G9), with three replications. The results indicated that the interaction was significant only between cultivation techniques and organic fertilization on plant height at 8 weeks after planting (WAP) and leaf number at 5 WAP. However, rice cultivation techniques significantly affected almost all observation variables, whereas organic fertilization significantly affected only plant height at 8 WAP. In relation to yield, the aerobic rice system wi...

Several fast‐growing and multipurpose trees such as exotic and valuable native species have been widely used in West Africa to reverse the tendency of massive degradation of plant cover and restore soil productivity. Although benefic effects have been reported on soil stabilization, a lack of information about their impact on soil symbiotic microorganisms still remains. This investigation has been carried out in field trees of 28 years old in a forest reserve at Bandia. To determine the mycorrhizal inoculum potential (MIP) of soils, a mycorrhizal bioassay was conducted using seedlings of Zea mays L. Spores concentration, arbuscular mycorrhizal (AM) fungi morphotypes and mycorrhizal colonization of field plants were examined. Results showed that fungal communities were dominated in all samples by the genus Glomus. Nevertheless, the others genera Gigaspora and Scutellospora occurred preferentially out of the plantations. The number and richness of spores as well as the MIP of soils we...

Sri Lanka has an enormous diversity of medicinal plants, and most are in dry zone forests. Mihintale sanctuary has some of the widely used medicinal plants in our ayurvedic system. Vesicular Arbuscular mycorrhiza (VAM) is the most abundant form of mycorrhiza and, plays a very important role in enhancing plant growth by increased nutrient uptake. This study investigates the presence of VAM colonization in several selected medicinal plants in disturbed and undisturbed sties in the Mihintale sanctuary. The results may be used to conserve those medicinal plants from destruction due to over exploitation. Root Samples were taken randomly from fourteen plant species in both disturbed and undisturbed sites in order to determine the effect of soil disturbance due to human activities on VAM colonization. Sub samples of fine roots of each species were quantified for VAM colonization by performing standard procedures. All the species had VAM colonization but was relatively higher with the plants in undisturbed site than in disturbed site. . Results indicate that the soil disturbances cause a decrease in VAM colonization in the study species.

Two concurrent field experiments were conducted to compare the heavy metals (HMs) uptake by Acacia mangium and Eucalyptus urophylla inoculated with mycorrhizal inoculants available locally and abroad, following Randomized Complete Block Design (RCBD). After 27 months in a mined-out area in Barangay Capayang, Mogpog, Marinduque, representative trees were excavated where soil and tissue samples were analyzed for HMs. Parameters measured were: HM accumulation and uptake, bioconcentration factor (BCF) (root to soil HMs concentration ratio), and translocation factor (TF) (shoot-root quotient). Results show that accumulation of HMs in plant tissues of both forest species is in the following order: copper (Cu) > lead (Pb) > cadmium (Cd). Mycorrhizal plants had higher HMs uptake as compared with the non-mycorrhizal counterparts. Mycogroe-inoculated A. mangium had the highest Cd (2.05 ± 0.54 mg kg-1) and Cu (1799 ± 896 mg kg-1) uptake. Based on the BCF and TF values, mycorrhizal plants did not consistently show increasing accumulation with above plant parts with the exception of USA Ped-inoculated E. urophylla with potential to translocate Cd and Pb into its upper parts. Mycogroe-inoculated A. mangium is a good candidate as Cd and Cu phytoremediator while USA-Ped inoculated E. urophylla has the potential to accumulate Cd and Pb.

Background and Aims
Leaf litter constitutes a major fraction in litter production in Masson pine forests. However, productivity declines due to infertile soil. In these plantations, fertilization is a key management practice to sustain productivity. Our study aimed to: (1) evaluate the effect of mineral fertilizer on the decomposition dynamic of leaf litter; (2) evaluate its effect on amino acid concentration; and (3) explore the relationship between soil properties and amino acid.
Methods
Leaf litters of Masson pine were placed into litter bags in the following treatments: Control (CK), N fertilization (+N), N and P fertilization (+NP), and N, P, K fertilization (+NPK) and collected every three months during 12 months of decomposition. Litterbags and chromatography techniques were employed to assess litter mass and amino acid concentration.
Results
Our study found that Masson pine leaf litter significantly affected by fertilizers, and the decomposition process accelerated with +NPK, and +NP. Out of the 16 amino acids, only GAALAGL showed significant increase under fertilizer treatments. The total amino acid concentrations were 229.33±4.46, 205.37±4.49, 206.28±4.17, 186.74±4.32 mg/g, respectively, in +NPK, +NP, +N, and CK. Soil chemical properties had a negative effect on amino acid concentration except for GVITMAS. N and P concentrations in leaf litter significantly increased while K concentration decreased; similarly, soil N and P exhibited significant increases, while K decreased.
Conclusions
NPK fertilizer might be the preferred management option as it can positively impact leaf litter decomposition and increase amino acid concentration. The findings serve as a valuable reference for implementing fertilization strategies in subtropical forests.

Arbuscular mycorrhizal fungi (AMF) are potential biofertilizers for plants. The succeed and quality of AMF inoculation is related to the type of AMF and plants. This study aimed to find the most effective AMF species in Indigofera zollingeriana nurseries. This experiment study was designed using a completely randomized design with six treatments and five replications based on different types of AMF in single and consortium forms. Treatment details include: IFMIX (consortium: a mixture of five types of AMF), IFTE (Glomus etinucatum), IFTM (Glomus manihotis), IFTA (Acaulospora tuberculata), IFTG (Gigaspora margarita), IFTS Glomus sp. Data were analyzed using Analysis of Variance (ANOVA) and Duncan's Multiple Range Test. Based on the results of variance, AMF inoculation at Indigofera zollingeriana nurseries in a single form (IFTE, IFTM, IFTA, IFTG, and IFTS) resulted in effectiveness that was not significantly different with the consortium FMA inoculation (IFMIX) against AMF coloni...

Sphagnum mosses mediate long-term carbon accumulation in peatlands. Given their functional role as keystone species, it is important to consider their responses to ecological gradients and environmental changes through the production of phenolics. We compared the extent to which Sphagnum phenolic production was dependent on species, microhabitats and season, and how surrounding dwarf shrubs responded to Sphagnum phenolics. We evaluated the phenolic profiles of aqueous extracts of Sphagnum fallax and Sphagnum magellanicum over a 6-month period in two microhabitats (wet lawns versus dry hummocks) in a French peatland. Phenolic profiles of water-soluble extracts were measured by UHPLC-QTOF-MS. Andromeda polifolia mycorrhizal colonization was quantified by assessing the intensity of global root cortex colonization. Phenolic profiles of both Sphagnum mosses were species-, season-and microhabitat-dependant. Sphagnum-derived acids were the phenolics mostly recovered; relative quantities were 2.5fold higher in S. fallax than in S. magellanicum. Microtopography and vascular plant cover strongly influenced phenolic profiles, especially for minor metabolites present in low abundance. Higher mycorrhizal colonization of A. polifolia was found in lawns as compared to hummocks. Mycorrhizal abundance, in contrast to environmental parameters, was correlated with production of minor phenolics in S. fallax. Our results highlight the close interaction between mycorrhizae such as those colonizing A. polifolia and the release of Sphagnum phenolic metabolites and suggest that Sphagnum-derived acids and minor phenolics play different roles in this interaction. This work provides new insight into the ecological role of Sphagnum phenolics by proposing a strong association with mycorrhizal colonization of shrubs.

Sphagnum mosses mediate long-term carbon accumulation in peatlands. Given their functional role as keystone species, it is important to consider their responses to ecological gradients and environmental changes through the production of phenolics. We compared the extent to which Sphagnum phenolic production was dependent on species, microhabitats and season, and how surrounding dwarf shrubs responded to Sphagnum phenolics. We evaluated the phenolic profiles of aqueous extracts of Sphagnum fallax and Sphagnum magellanicum over a 6-month period in two microhabitats (wet lawns versus dry hummocks) in a French peatland. Phenolic profiles of water-soluble extracts were measured by UHPLC-QTOF-MS. Andromeda polifolia mycorrhizal colonization was quantified by assessing the intensity of global root cortex colonization. Phenolic profiles of both Sphagnum mosses were species-, season-and microhabitat-dependant. Sphagnum-derived acids were the phenolics mostly recovered; relative quantities were 2.5fold higher in S. fallax than in S. magellanicum. Microtopography and vascular plant cover strongly influenced phenolic profiles, especially for minor metabolites present in low abundance. Higher mycorrhizal colonization of A. polifolia was found in lawns as compared to hummocks. Mycorrhizal abundance, in contrast to environmental parameters, was correlated with production of minor phenolics in S. fallax. Our results highlight the close interaction between mycorrhizae such as those colonizing A. polifolia and the release of Sphagnum phenolic metabolites and suggest that Sphagnum-derived acids and minor phenolics play different roles in this interaction. This work provides new insight into the ecological role of Sphagnum phenolics by proposing a strong association with mycorrhizal colonization of shrubs.

Arbuscular mycorrhizal fungi (AMF) are root bound symbiotes that are present in most terrestrial ecosystems. AMF belongs to the Phylum Glomeromycota, with more than 300 species. Mycorrhizal colonization in tropical ecosystems is affected by biotic and abiotic factors. The abundance and diversity of AMF decreases when having degraded soils and contamination produced by agricultural and agrochemical practices. The in vitro propagation of AMF alters the morphology, genetics and functioning given the domestication of the strains. It is important to further examine the effects of domestication on AM fungi and predict how changes could highly affect the environment following inoculation with such strains. Future progress prelude to the development of a future 'ecological engineering of AMF and their associated microorganisms' and its integration into modern plant breeding while taking care of the ecosystem services rendered by these valuable fungi.

The study assessed the effects of paring, oil palm bunch refuse and sawdust mulch on growth performance of the first three suckers following plantain mother plant. A 2 x 3 factorial experiment was laid out in a randomized complete block design on the field in Akure, Nigeria. At flowering of each mother plant, growth parameters of each of the three suckers were measure and population densities of plant parasitic nematodes in the rhizosphere of the flowered plants were assessed. Results showed that mulching and paring impacted positively on suckering pattern. The better growth performance was obtained on mats mulched with oil palm bunch refuse and this is related to the higher nutrient level obtained in the rhizosphere compared with that of the sawdust mulch and the control. Therefore, the result of this study placed emphasis on the importance of the quality of the mulch material used. Generally, paring enhanced the benefit derived from mulch but the level or extent of the benefit is accentuated by the quality of the mulch material used. This signified that cycling rate is enhanced when planting materials are "cleaned" by physical disinfecting before planting. This is expected to reflect positively on cumulative annual yield. Helicotylenchus dihystera, H. multicinctus, Meloidogyne spp., Pratylenchus coffeae and Radopholus similis were recovered from the rhizosphere of the flowered mother plant. Higher densities of nematodes were observed in the non-pared treatments compared with pared and this established paring as an effective pre-plant cultural practice aimed at cleaning plantain sucker planting materials. Additionally, mulch depressed the densities of P. coffeae but not that of R. similis, implying that organic input may effectively control the former but not the latter. This underscored the complexity of managing plant parasitic nematodes as a result of concomitant parasitism.

Agronomic inputs and technologies, especially fertilizers, act on the evolution of the symbiotic partnership between arbuscular mycorrhizal fungi and cultivated plants. The use of the MycoPatt method for the assessment of mycorrhizas in maize roots leads to the extraction of large parameter databases with an increased resolution over the colonization mechanism. The application of a biostimulator treatment on plants acted toward a reduction of root permissiveness for mycorrhizas. The phenomenon was noticeable through an increased colonization variability that overlapped with plant nutritional needs. The annual characteristic of the plant was highlighted by the simultaneous presence of arbuscules and vesicles, with a high share of arbuscules in the advanced phenophases. Colonized root parts presented numerous arbuscule-dominated areas in all phenophases, which indicated a continuous formation of these structures and an intense nutrient transfer between partners. Mycorrhizal maps showe...

Cork oak (Quercus suber L.) forests play an important ecological and economic role. Ectomycorrhizal fungi (ECMF) are key components for the sustainability and functioning of these ecosystems. The community structure and composition of ECMF associated with Q. suber in different landscapes of distinct Mediterranean bioclimate regions have not previously been compared. In this work, soil samples from cork oak forests residing in different bioclimates (arid, semi-arid, sub-humid, and humid) were collected and surveyed for ectomycorrhizal (ECM) root tips. A global analysis performed on 3565 ECM root tips revealed that the ECMF community is highly enriched in Russula, Tomentella, and Cenoccocum, which correspond to the ECMF genera that mainly contribute to community differences. The ECMF communities from the rainiest and the driest cork oak forests were distinct, with soils from the rainiest climates being more heterogeneous than those from the driest climates. The analyses of several abiotic factors on the ECMF communities revealed that bioclimate, precipitation, soil texture, and forest management strongly influenced ECMF structure. Shifts in ECMF with different hyphal exploration types were also detected among forests, with precipitation, forest system, and soil texture being the main drivers controlling their composition. Understanding the effects of environmental factors on the structuring of ECM communities could be the first step for promoting the sustainability of this threatened ecosystem.

Mycorrhiza fungi are important components of soil microbiota in the rhizosphere and greatly influence the uptake of mineral elements by plants. A greenhouse experiment was conducted at the University of Embu to evaluate effect of Aspilia pruliseta rhizosphere mycorrhiza on phosphorus uptake by gadam sorghum. Pots were filled with soil from a predetermined source in the semi-arid Gakurungu, Tunyai and Kanyuambora regions of Kenya. A completely randomized block design was used with each treatment replicated four times giving n=144.  Regular watering was maintained for thirty-five days. Data were analyzed using three-way ANOVA. Seed emergence, hypocotyl development and stand count were enhanced at P≤0.05 in both mycorrhiza fungi inoculated gadam sorghum seeds and in pots whose soils were taken from the rhizosphere of A. pruliseta plants. The growth attributes had a positive correlation with yield at 95% confidence. Soil phosphate level was enhanced where seed inoculation with mycorrhiz...

Axenic cultures of Suillus bovinus were cultivated in inorganic liquid medium with glucose as a carbon source at 25 °C and continuous supply of oxygen by aeration with compressed air in the dark. Exogenous fructose as sole carbon source yielded about 50% less increase in dry weight than glucose. This resulted from different uptake velocities. Sucrose as sole exogenous carbon source yielded no measurable increase in dry weight. In glucose cultures, activities of all glycolytic enzymes were found. Maximum specific activ ities varied largely (from about 60 [fructose 6-phosphate kinase] to about 20 000 [triosephosphate isomerase] nmoles • mg protein-1 • m in-1). A pparent K m-values also varied over more than two orders of magnitude (0.035 m M [pyruvate kinase] to 6.16 m M [triosephosphate iso merase]). Fructose 6-phosphate kinase proved to be the fructose 2,6-bisphosphate-regulated type, aldolase the divalent cation-dependent (class II) type and glyceratephosphate mutase the glycerate 2,3-phosphate-independent type of the respective enzymes. Eight of the 10 enzymes exhibited pH-optima' between 7.5-8.0. Triosephosphate isomerase and pyruvate ki nase showed highest activities at pH 6.5. Regulatory sites within the glycolytic pathway of Suillus bovinus are discussed; fructose 6-phosphate kinase appears to be its main bottle neck.

The effect of arbuscular mycorrhizal fungi (AMF) on growth and element uptake by Ni-hyperaccumulating plant, Berkheya coddii, was studied. Plants were grown under laboratory conditions on ultramafic soil without or with the AM fungi of different origin. The AM colonization, especially with the indigenous strain, significantly enhanced plants growth and their survival. AMF affected also the elemental concentrations that were studied with Particle-induced X-ray emission (PIXE). AMF (i) increased K and Fe in shoots, Zn and Mn in roots, P and Ca both, in roots and shoots; (ii) decreased Mn in shoots, Co and Ni both, in shoots and roots. Due to higher biomass of mycorrhizal plants, total Ni content was up to 20 times higher in mycorrhizal plants compared to the non-mycorrhizal ones. The AMF enhancement of Ni uptake may therefore provide an improvement of a presently used technique of nickel phytomining.