Mycorrhizal Species Research Articles

Arbuscular mycorrhiza has limited effects on yield and quality of tomatoes grown under soilless cultivation

A study was conducted investigating the possible utilization of mycorrhiza to enhance yield and quality of tomatoes grown in a soilless culture system using sawdust or coir as growing media. The experiment was carried out in temperature-controlled and non-temperature-controlled (NTC) tunnels. Fertigation was applied at three levels (100%, 75%, and 50%) of the recommended nutrient concentration. Mycoroot™, containing four arbuscular mycorrhizal species (Glomus etunicatum, Paraglomus occultum, Glomus clarum, and Glomus mosseae), was applied at seeding, as well as transplanting. Growing tomatoes under reduced nutrient supply reduced the total soluble solids in the juice of the fruits, but improved total and marketable yield, as well as the number of marketable fruits. This effect was more substantial in the temperature-controlled tunnel than in the NTC tunnel. Fruit firmness and leaf chlorophyll concentrations were significantly higher in plants grown in the temperature-controlled tunnel. Growing tomatoes in sawdust improved the leaf Mn and Ca concentration over that of tomato plants grown in coir. Mycorrhiza colonization did not have a beneficial effect on tomato yield and quality. Further studies, including different media, nutrient composition, and concentration need to be carried out to investigate the possible effect of AMF failing to improve yield, despite AMF root colonization, and to reveal the cause of the poor beneficial effect of AMF on tomato plants grown under soilless culture.

Nutrient input from hemiparasitic litter favors plant species with a fast-growth strategy

Hemiparasitic plants often produce nutrient-rich litter with high decomposition rates, and thus can enhance nutrient availability. When plant species have differential affinities for this nutrient source, hemiparasitic litter might influence species composition in addition to the parasitic suppression of host species. We expected that species adapted to fertile habitats derive a higher proportion of nutrients from the hemiparasitic litter compared to other species. 15N-labeled litter of Rhinanthus angustifolius and Pedicularis sylvatica was added to experimental field plots and adjacent litter bags. We examined N release from the litter, N uptake by the vegetation 2, 4 and 12 months after litter addition and differences in the proportion of N taken up from the litter (NL) between co-occurring species. The percentage of N in shoots of co-occurring plant species that is derived from the added hemiparasitic litter (NL) strongly differed between the species (0.1–6.2 %). After exclusion of species with an alternative N source (legumes as well as ectomycorrhizal and ericoid mycorrhizal species), NL was positively related (p < 0.001) with specific leaf area (SLA) and at Pedicularis sites with leaf N concentration (LNC) and leaf phosphorus concentration (LPC) (p < 0.05), i.e. leaf traits associated with a fast-growth strategy and adaptation to high-nutrient environments. Our results suggest that nutrient release from hemiparasitic litter favors plant species with a fast-growth strategy adapted to high-nutrient environments compared to species with a slow-growth strategy. Whether continued hemiparasitic litter inputs are able to change species composition in the long term requires further research.

The greater effectiveness of Glomus mosseae and Glomus intraradices in improving productivity, oil content and tolerance of salt‐stressed menthol mint (Mentha arvensis)

Mentha arvensis is cultivated in large parts of the world for its menthol-rich essential oil. The study investigates the potential of four mycorrhizal fungi, viz. Glomus mosseae (Gm), Glomus aggregatum (Ga), Glomus fasciculatum (Gf) and Glomus intraradices (Gi) in alleviating NaCl-induced salt stress in Mentha arvensis cv. Kosi and establishes the specificity of interaction between different mycorrhizal species and their effectiveness in mitigating salt stress in Mentha arvensis. Mycorrhizal and non-mycorrhizal Mentha plants were subjected to NaCl-induced salinity. Among the four Glomus species, Gm and Gi reduced salt-induced herb yield losses: a loss of 27.53% and 25.58% respectively under salt stress in comparison to 51.00% in non-mycorrhizal M. arvensis salt-stressed plants. Gm- and Gi-inoculated plants also recorded higher leaf:stem ratio, oil content, and oil yield and menthol concentration in essential oil under both saline and non-saline conditions. Better performance in terms of herb yield, and oil content and yield was observed in Gi- and Gm-inoculated M. arvensis plants, suggesting the capability of Gi and Gm in protecting plants from the detrimental effects of salt stress; beneficial effects of arbuscular mycorrhizal fungi, however, may vary with host and environment.

Adventitious rooting in apple rootstock MM.106: Effects of arbuscular mycorrhizal fungi (AMF) and plant growth regulators

SummaryTo assess the efficacy of arbuscular mycorrhizal fungi (AMF) for improving the rooting and growth of hardwood cuttings of apple rootstock MM.106, three mycorrhizal species (Sclerocystis dussi, Glomus intraradices, and G. fasciculatum) were tested. Rootstock cuttings from each AMF inoculation treatment were then treated, or not treated, with the rooting hormone, indole 3-butyric acid (IBA), or a rooting inhibitor, cinnamic acid (CA) each at 2.5 g l–1. Cuttings that had not been inoculated with AMF or treated with either growth regulator served as controls. The results indicated that, after 90 d, cuttings inoculated with any of the three AMF alone, or in combination with 2.5 g l–1 IBA had significantly higher percentages of rooting and growth than the untreated controls. The combined application of AMF plus 2.5 g l–1 CA also improved the rooting percentage, which was significantly higher than in the untreated controls. Thus, the positive response to AMF inoculation was further improved when combined with 2.5 g l–1 IBA.

Ectomycorrhizal diversity at five different tree species in forests of the Taunus Mountains in Central Germany

Ectomycorrhizal fungi were investigated on five different forest tree species growing in pure stands on the south slope of the Taunus Mountains, which are situated at the northern end of the Rhine rift valley in Central Germany. Mycorrhizal fungi accompanying the genus Xerocomus were identified and their frequencies counted. Using ITS markers, 22 different fungal species were identified down to species level and 6 down to genus level. On European beech (Fagus sylvatica) 16 fungal species and 4 genera were identified and on Sessile oak (Quercus petraea) 16 ectomycorrhizal species and 2 genera were determined. On both deciduous trees we observed exclusively: Cortinarius subsertipes, Genea hispidula, Lactarius quietus, Tylopilus felleus and a Melanogaster genus. On Norway spruce (Picea abies) we identified 13 different mycorrhizal species and 3 different genera, on Silver fir (Abies alba) 12 species and 3 genera, and in association with European larch (Larix decidua) 11 species and 3 genera. On these conifers Cortinarius anomalus, Lactarius necator and a Piloderma genus occurred exclusively. Comparisons with published data of ectomycorrhizal diversity on the same five tree species, growing in different areas of Germany and Europe, led to the conclusion that there is relative site specificity for ectomycorrhizal communities. Upper soil compartments of the stands investigated in the Taunus Mountainssuffer from soil acidification (pH-H20 ~3.7 to ~4.8). However, a clear correlation between upper soil pH-values and fungal diversity was not observed. On the other hand, nitrate concentrations in upper soil compartments (~26 to ~91 kgNO3-/ha) were higher in older stands as compared to younger ones. Higher nitrate concentrations in upper soils correlated with lower numbers of mycorrhizal individuals.

Seasonal Variation in Arbuscular Mycorrhizal Fungi Root Colonization of Cheatgrass (Bromus tectorum), an Invasive Winter Annual

Cheatgrass is a highly invasive winter annual grass that is most aggressive in the semi-arid steppe region of western North America. In this region, cheatgrass invasion becomes so severe that virtual monocultures can result. Due to its strategy for growth from autumn to spring, cheatgrass remains active during winter months when most native vegetation is dormant. This shift in host activity could be important for beneficial soil microbes, particularly the arbuscular mycorrhizal fungi (AMF), as they are adapted for coincidental growth with host plants. Many native plant species that are utilized for restoring areas invaded by cheatgrass associate with AMF, so any reduction in these symbiotic fungi could reduce the successful establishment of desirable plant species. Although cheatgrass is recognized as a facultative associate of AMF, its associations with AMF across seasons and throughout its lifespan are not known. We measured AMF colonization of cheatgrass roots from soon after germination through senescence. We found that cheatgrass remains colonized throughout its life. Colonization drops dramatically once soil temperatures approach freezing, but was highest late in the growth cycle of cheatgrass during flowering and seed set. Colonization by AMF never attained levels comparable to highly mycorrhizal plant species. This indicates that cheatgrass is a poor host for AMF throughout its life, and long-term dominance by cheatgrass could alter AMF in soils. Restoring highly invaded sites quickly following invasion might reduce the negative effects of cheatgrass on this important soil microbial community.

Effects of arbuscular mycorrhizal inoculation on growth, yield, nutrient uptake and irrigation water productivity of sunflowers grown under drought stress

Drought stress is one of the most important limiting factors for field crops in arid and semi-arid regions. Yield assessments under drought stress conditions, using soil microorganisms to reduce the damage from drought stress, demonstrate that soil microorganisms are sustainable solutions for crop production in such climates. Therefore, we undertook a two year experiment to understand the effects of root colonization by two species of mycorrhizal fungi (Glomus mosseae and Glomus hoi), under different drought stress conditions, quantifying sunflower growth, nutrient uptake, yield, yield components, oil percentage and irrigation water productivity. The experiment was conducted at Tarbiat Modares University, located in the semi-arid region of Iran, during the 2006 and 2007 growing seasons. Drought stress was induced at two stress levels by irrigating after 60 and 80% water depletion, which were defined as mild and severe drought stress, respectively. Irrigating after 40% water depletion was considered to be normal irrigation (no stress). The results indicated that irrespective of the mycorrhizal species and the drought stress intensity, inoculated plants produced more dry matter, heavier seeds and greater seed and oil yields than did non-inoculated plants. Interestingly, the seed yields of plants inoculated with G. mosseae under each irrigation regime were higher than those of plants inoculated with G. hoi, or of the non-inoculated plants. Although drought stress reduced the N percentages in the leaves and seeds, mycorrhizal fungi enhanced the N percentages, particularly when the plants were inoculated with G. mosseae. In addition, seed P percentages were not affected by mycorrhizae in 2006. In contrast, the highest P percentages in both leaves and seeds were obtained from plants inoculated with G. mosseae in 2007. Overall, our results show that G. mosseae is more efficient under drought stress, and better supports sunflower plants. The application of these microorganisms could be critical in the cultivation of sunflowers under arid and semi-arid conditions, where water is the most important factor in determining plant growth and yield.

Effects of different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower under water stress

The role of arbuscular mycorrhizal fungi in alleviating water stress is well documented. In order to study the effects of water stress and two different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower, a field experiment as split plot design with three replications was conducted in the Research Field Station, Zabol University, Zabol, Iran in 2011. Water stress treatments included control as 90% of field capacity (W1), 70% field capacity (W2) and 50% field capacity (W3) assigned to the main plots and two different mycorrhiza species, consisting of M1=control (without any inoculation), M2=Glumus mossea and M3=Glumus etanicatum as sub plots. Results showed that by increasing water stress from control (W1) to W3 treatment, grain yield was significantly decreased. The reduction in the level of W3 was 15.05%. The content of potassium in seeds significantly decreased due to water stress but water stress upto W2 treatment increased the content of phosphorus, nitrogen and oil content of seeds. In between two species of mycorrhiza in sunflower plants, Glumus etanicatum had the highest effect on grain yield and these elements in seeds and increased both.

Auxin influences strigolactones in pea mycorrhizal symbiosis

Hormone interactions are essential for the control of many developmental processes, including intracellular symbioses. The interaction between auxin and the new plant hormone strigolactone in the regulation of arbuscular mycorrhizal symbiosis was examined in one of the few auxin deficient mutants available in a mycorrhizal species, the auxin-deficient bsh mutant of pea (Pisum sativum). Mycorrhizal colonisation with the fungus Glomus intraradices was significantly reduced in the low auxin bsh mutant. The bsh mutant also exhibited a reduction in strigolactone exudation and the expression of a key strigolactone biosynthesis gene (PsCCD8). Strigolactone exudation was also reduced in wild type plants when the auxin content was reduced by stem girdling. Low strigolactone levels appear to be at least partially responsible for the reduced colonisation of the bsh mutant, as application of the synthetic strigolactone GR24 could partially rescue the mycorrhizal phenotype of bsh mutants. Data presented here indicates root auxin content was correlated with strigolactone exudation in both mutant and wild type plants. Mutant studies suggest that auxin may regulate early events in the formation of arbuscular mycorrhizal symbiosis by controlling strigolactone levels, both in the rhizosphere and possibly during early root colonisation.

Spotlight on the microbes that produce heat shock protein 90-targeting antibiotics

Heat shock protein 90 (Hsp90) is a promising cancer drug target as a molecular chaperone critical for stabilization and activation of several of the oncoproteins that drive cancer progression. Its actions depend upon its essential ATPase, an activity fortuitously inhibited with a very high degree of selectivity by natural antibiotics: notably the actinomycete-derived benzoquinone ansamycins (e.g. geldanamycin) and certain fungal-derived resorcyclic acid lactones (e.g. radicicol). The molecular interactions made by these antibiotics when bound within the ADP/ATP-binding site of Hsp90 have served as templates for the development of several synthetic Hsp90 inhibitor drugs. Much attention now focuses on the clinical trials of these drugs. However, because microbes have evolved antibiotics to target Hsp90, it is probable that they often exploit Hsp90 inhibition when interacting with each other and with plants. Fungi known to produce Hsp90 inhibitors include mycoparasitic, as well as plant-pathogenic, endophytic and mycorrhizal species. The Hsp90 chaperone may, therefore, be a prominent target in establishing a number of mycoparasitic (interfungal), fungal pathogen–plant and symbiotic fungus–plant relationships. Furthermore the Hsp90 family proteins of the microbes that produce Hsp90 inhibitor antibiotics are able to reveal how drug resistance can arise by amino acid changes in the highly conserved ADP/ATP-binding site of Hsp90.

Multiple origins of sequestrate basidiomes within Entoloma inferred from molecular phylogenetic analyses

The genus Entoloma comprises diverse trophic modes and basidiome morphologies. Although Entoloma includes some sequestrate species, their origins are not clearly understood in relation to phylogenetic position and trophic status. In this study, we collected 34 sequestrate Entoloma specimens in Japan over a 9-y period. Their identities and phylogenetic positions were determined by molecular analyses using three nuclear loci [internal transcribed spacer (ITS) and large subunit (LSU) regions of rDNA and RNA polymerase II second LSU (rpb2) gene]. Based on species delimitation of 97 % sequence matches in the ITS region, which is a suitable region for species-level identification of higher fungi, we identified four sequestrate Entoloma species. Molecular phylogenetic analyses that included all related sequences in the International Nucleotide Sequence Database revealed that the four sequestrate Entoloma species belonged to two major phylogroups. One of the phylogroups was Inocephalus–Cyanula, which is composed only of saprotrophic species. Three of the Japanese sequestrate species, as well as three previously known sequestrate species from other regions, fell into at least two independent clades in this phylogroup, indicating multiple origins of sequestrate forms within this saprotrophic lineage. Another phylogroup, Rhodopolioid, was also shown to include a sequestrate species for the first time. Because the Rhodopolioid phylogroup is composed exclusively of mycorrhizal species (ectomycorrhizal and tuberculate mycorrhizal species), the sequestrate form may also have evolved from a mycorrhizal ancestor. Our results suggest that sequestrate basidiomes have evolved multiple times, irrespective of their trophic status in Entoloma. Finally, based on molecular and morphological characteristics, here we describe two new sequestrate Entoloma species, i.e., Entoloma prismaticum Sasaki, Kinoshita et Nara, sp. nov. and Entoloma hypogaeum Sasaki, Kinoshita et Nara, sp. nov.

DO MAIZE AND PEPPER PLANTS DEPEND ON MYCORRHIZAE IN TERMS OF PHOSPHORUS AND ZINC UPTAKE?

Nutrient deficiency, especially zinc (Zn) and phosphorus (P), is a common nutritional problem for the production of some crops in Turkey. This problem results in the application of increasing amounts of several fertilizers. Mycorrhizal inoculation or the indigenous potential of mycorrhizae in the soil is a critical factor in crop production under low supply of Zn and P. The effects of selected mycorrhizal inoculation on growth and Zn and P uptake of maize and green pepper were investigated in Zn- and P-deficient calcareous soils from Central Anatolia. Soils were sterilized by autoclaving and plants were grown for 7 weeks in pots under greenhouse conditions with inoculation of two selected arbuscular mycorrhizal (AM) species (Glommus moseea and G. etunicatum) at three rates of P (0, 25, 125 mg P kg−1 soil) and two rates of Zn (0 and 5 mg Zn kg−1soil). Without mycorrhizal inoculation, shoot and root dry matter production were severely affected by P and Zn deficiencies, and supply of adequate amounts of P and Zn significantly enhanced plant growth. When the soil was inoculated with mycorrhizal inoculation, the increasing effects of P and Zn fertilization on plant growth remained less pronounced. In accordance with growth data, mycorrhizae inoculation enhanced P and Zn concentration of plants, especially under low supply of P and Zn. The results obtained indicate that maize and green pepper are highly mycorrizal–dependent (MD) plant species under both low P and Zn supply and mycorrhizae play an essential role in P and Zn nutrition of plants in P and Zn-deficient soils. Although addition of P and Zn increased plant growth and plants are mycorrhizal dependent on P and Zn nutrition however dependence is much more dependent on P nutrition.

Different arbuscular mycorrhizal inoculants affect the growth and survival of Podocarpus cunninghamii restoration plantings in the Mackenzie Basin, New Zealand

There is increasing interest in the use of arbuscular mycorrhizal fungi (AMF) for ecological restoration, as AMF can improve plant nutrition and growth. However, some AMF can have negative effects on plant growth. It is therefore critical that restoration strategies incorporate appropriate AMF. This research investigated differences in growth and survival of Podocarpus cunninghamii (mountain tōtara) cuttings with six different AMF inoculums, with the aim of choosing the most appropriate mycorrhizal species for restoration success. Cuttings of P. cunninghamii were inoculated with AMF ranging from indigenous to exotic, including commercially available AMF and AMF isolated from remnant P. cunninghamii forest and ex-agricultural grassland. Plant growth and survival was compared after two seasons at a high country restoration site in the Mackenzie Basin. Plants treated with forest and indigenous AMF had significantly greater survival than those treated with commercial AMF. Forest AMF also resulted in significantly greater P. cunninghamii growth than all the other treatments. This has potentially important implications for restoration, as improved growth and survival of native woody species can improve restoration success by increasing establishment success and reducing management costs.

Mycorrhiza analyses in New Zealand truffières reveal frequent but variable persistence of Tuber melanosporum in co-existence with other truffle species

This study compiles the results from an examination of mycorrhizae on root samples from Tuber melanosporum truffières in New Zealand. Samples were taken over 5 years from 328 trees in 43 truffières established with nursery-inoculated trees. Mycorrhizae were analysed using a combination of morphological and molecular techniques, focusing on the identification of Tuber species. Results show that 49% of the trees, and nearly 90% of the truffières, retained T. melanosporum mycorrhizae up to 21 years after planting. Tuber mycorrhizae with spiky cystidia were found on 26.9% of the tested trees: Tuber brumale (5.5%), Tuber maculatum (10.7%), and unidentified Tuber species (10.7%), and were detected in 67% of the truffières tested. T. brumale was found in 28% and T. maculatum in 35% of the truffières. In 56% of the truffières, T. melanosporum was found to occur with spiky Tuber species. The existence of T. brumale and T. maculatum in the same truffière was recorded only once. Forty-four percent of trees examined had Scleroderma-like (SCL) mycorrhizae and 50% of trees hosted other ectomycorrhizal species (OE). For all categories of mycorrhizal species examined, the variation between truffières was greater than variation within each truffière. Overall results indicate that Corylus avellana tends to be more receptive to mycorrhizae of Tuber species than Quercus robur but is not necessarily more productive. In productive truffières, Q. robur appears to host SCL mycorrhizae more often than C. avellana. This is the first study of its scale to analyse the mycorrhizal species associated with T. melanosporum truffières in the Southern Hemisphere.

Wildfire and post-fire management effects on early fungal succession in Pinus mugo plantations, located in Curonian Spit (Lithuania)

The objective of this study was to evaluate the effects of wildfire and subsequent forest management on the diversity and functional community structure of fungi during early stage of succession in the coastal sand dunes of the Curonian Spit in Lithuania. 12 permanent study plots were established in multiple forest areas: burnt, not managed (B); burnt, clear-cut (C); burnt, clear-cut and reforested (R) and unburnt (U). During three years of the study, a total of 390 different fungal species were determined. The overall number of recorded species in studied post-fire variants comprised 52% (B), 41% (C) and 48% (R) of unburnt sites (U, 261 species). Significantly different species compositions were registered between C and B plots, while no difference was observed between C and R plots. Fungal communities of all burnt sites showed more significant differences stemming from annual changes rather than from types of forest management. Early succession of the post-fire fungal communities maintained the fungi from all defined taxonomical and functional groups. However, a certain alteration within some fungal life styles was observed. The wildfire has negatively impacted the lichens and the mycorrhizal species, as the percentages of these groups decreased from 15% and 12% in U plots to 10% and 3% in B plots. Wood saprobic fungi and soil saprobes were affected negatively by harvesting of the burnt trees that reduced their percentage from 38% and 8% in B plots to 27% and 4% in C plots. Soil-associated fungi were less affected both by fire and post-fire management than the fungi inhabiting above-ground substrates. The percentage of soil-associated fungi initially increased in the burnt sites, but two years after the fire it returned to the pre-fire level. No significant effect on soil-inhabiting fungi was noted for the differently managed post-fire sites.

Arbuscular Mycorrhizal Fungal Diversity in Sugarcane Rhizosphere in Relation with Soil Properties

Arbuscular mycorrhizal (AM) species diversity and their root colonization patterns may vary in a plant species as influenced by soil environmental and biological factors. In the present study, sugarcane rhizospheric soils were collected from 41 main sugarcane producing tehsil places belonging to 10 districts from Maharashtra, India. Rhizospheric soil samples and roots were analyzed for spore density, relative abundance and frequency of AM spores at genus as well as at species level, extent of AM colonization in roots and various soil chemical properties. Soil sample from Jalgaon district possessed maximum spore density and AM root colonization. Genus Glomus exhibited highest relative abundance with maximum frequency of 32.55%. Species wise, Glomus fasciculatum possessed highest relative abundance and maximum frequency was observed in case of Glomus fasciculatum, Glomus intraradices, Glomus mosseae and Glomus versiforme. Maximum similarity of AM spores was recorded between Satara and Sangli districts which may be because of almost similar soil pH profile. Data obtained after cluster analysis represented the close relationship between spore density, AM root colonization and soil Cu, Zn and Fe concentrations. A statistically significant positive correlation was also found when AM spore density and root colonization was compared with soil Cu, Zn and Fe contents. This kind of data can be used to predict type of AM fungi to be used as bioinoculant in particular region.

Fungos micorrízicos arbusculares afetando a produção de mudas de pinhão-manso na região sul do Estado de Tocantins, Brasil

O presente trabalho teve como objetivo avaliar os efeitos da inoculação de quatro espécies de fungos micorrízicos arbusculares no crescimento e nutrição de mudas de pinhão-manso. Foram utilizados 12 tratamentos e 10 repetições, sendo: a inoculação individual (Scutellospora calospora, Glomus clarum, Gigaspora margarita, Acaulospora morrowiae), em dupla das espécies (S. calospora + G. clarum, S. calospora + G. margarita, S. calospora + A. morrowiae, G. clarum + G. margarita, G. clarum + A. morrowiae e G. margarita + A. morrowiae), com a mistura das quatro espécies de micorrizas (MIX) e a testemunha sem inoculação com micorrizas. Para os teores de macro e micronutrientes, 75 dias após a emergência das plantas, diferenças significativas (p &lt; 0,05) foram observadas para os teores de nitrogênio (N), fósforo (P), potássio (K), magnésio (Mg), enxofre (S), manganês (Mn) e boro (B), com destaque para a inoculação com G. clarum e A. morrowiae isoladamente e em dupla inoculação. Para a biomassa da parte aérea e raiz, colonização micorrízica e eficiência micorrízica, as maiores médias (p &gt; 0,005) foram observadas para os tratamentos com G. clarum e A. morrowiae inoculados isoladamente e para a dupla inoculação de S. calospora + G. clarum e G. clarum + A. morrowiae.

Biochemical Changes inAcacia Senegaldue to Bioinnoculants

In a controlled pot experiment, agroforestry legume trees Acacia senegal (L.) Willd. seedlings were inoculated with different bioinnoculants like Arbuscular Mycorrhizal Fungal species and plant growth promoting rhizobacteria, which were isolated by extraction from the rhizosphere soil of Acacia senegal from different localities of western Rajasthan and was evaluated for enhancement of biochemical parameters mainly Peroxidase (PRO) and Polyphenol oxidase (PPO) activities. The considerable increase in PRO and PPO by bioinnoculants may be significant in protecting this tree from attacking pathogens. All bioinnoculants show beneficial effect; while the dual combination of both G. fasciculatum and Rhizobium being the most promoting of all biochemical parameters.

Effects of arbuscular mycorrhizal inoculation on biochemical parameters in Capsicum annuum grown under long term salt stress

Salt stress is an important environmental stress. Plants cope with salt stress with different strategies. In this study the effects of 2 different arbuscular mycorrhiza species (Glomus mosseae and G. intraradices) on some biochemical parameters in pepper plants (Capsicum annuum L. cv. Cumaovası) exposed to long term salt stress were studied. It was found that mycorrhizal inoculation increased RWC, P, total chlorophyll, and carotenoid content of pepper plants during salt application. The enzyme activities changed depending on the enzyme and salt stress application. The lowest MDA content was found in the plants inoculated with G. intraradices; however, there was no significant difference between the NaCl applications. It was found that plants inoculated with G. intraradices had less lipid peroxidation, and therefore it can be said that these plants have an advantage under salt stress.

Growth and Nutrient Uptake Responses of Kinnow to Vesicular Arbuscular Mycorrhizae

In a field experiment, three-year-old Kinnow trees budded on Jatti Katti (C. jambhiri) rootstock were inoculated by three different arbuscular mycorrhiza (AM), Glomus manihotis (T1), Glomus mosseae (T2), and Gigaspora gigantia (T3), separately or in combination (T4). Microscopic assessment of AM colonization on Kinnow roots showed a relatively lower level of infection by different species when inoculated separately than when inoculaed together. Application of AM improved growth parameters like plant height, canopy volume, mean leaf area, and number of new shoots per plant but had no effect on trunk diameter, number of leaf per new shoot and new shoot diameter. Flowering phenology was also altered by AM infection. The infected plants produced more flowers which despite abscission caused an increase in the initial number of fruits. AM inoculation increased plant phosphorous in T3, potassium in T1, T2, T3, calcium in T2, T3, T4, and the AM-nutrient relationship did not reveal any generalized pattern. Inoculated plants, however, had higher concentration of different elements by the second year of the experiment indicating towards the continuous and cumulative effect of AM infection on plant nutrient accumulation. Further, the beneficial effects of AM on Kinnow were not related to the difference in the species of mycorrhiza.