Food preferences of a fungal-feeding Aphelenchoides species

Nematology ◽  
2000 ◽  
Vol 2 (2) ◽  
pp. 223-230 ◽  
Author(s):  
Liliane Ruess ◽  
Erick J. Garcia Zapata ◽  
John Dighton
Keyword(s):  
Mycorrhizal Fungi ◽  
Food Source ◽  
Food Preferences ◽  
Fungal Species ◽  
Fungal Host ◽  
Toxic Metabolites ◽  
Mycorrhizal Associations ◽  
Marked Preference ◽  
Choice Chamber

Abstract The growth of Aphelenchoides sp. populations was investigated in vitro with 17 different fungal species as food source. Nematode mass cultures were obtained with saprophytic (Agrocybe, Chaetomium) and especially with mycorrhizal fungi (Cenococcum, Hymenoscyphus, Laccaria). Mitosporic species, like Alternaria, Monocillium or Penicillium, were generally meagre or non-hosts. This poor host suitability is likely due to the release of toxic metabolites (e.g. antibiotics) and/or to morphological differences (e.g., forming of conidiophores) by the fungi. Frequent grazing of nematodes on mycorrhizal mycelia may be of major significance for the establishment and maintenance of mycorrhizal associations in the field. Food preference of Aphelenchoides sp. was tested in choice chamber experiments. Nematodes showed a marked preference for particular fungal species. They changed food source with time, indicating a “mixed diet” selection, probably a strategy to avoid the concentration of toxic metabolites. The attractiveness of a fungus was not necessarily correlated with its suitability as a host. That a poor fungal host can be a strong nematode attractant and influence their spatial distribution in the soil has implications for nematode populations in the field. In Laborexperimenten wurde die Vermehrung des Nematoden Aphelenchoides sp. mit 17 verschiedenen Pilzspezies als Nahrungsgrundlage untersucht. Neben saprophytischen Arten (Agrocybe, Chaetomium) eigneten sich insbesondere Mykorrhizapilze (Cenococcum, Hymenoscyphus, Laccaria) für eine Massenvermehrung. Eine schlechte Nahrungsquelle stellten mitosporische Arten, wie Alternaria, Monocillium oder Penicillium, dar. Dies dürfte auf toxische Stoffwechselprodukte (z.B., Antibiotika) und/oder auf morphologische Unterschiede (z.B., Sporenbildung) zurückzuführen sein. Die gute Vermehrung der Nematoden an Mykorrhizapilzen ist von weitreichender Bedeutung für das Freiland. Negative Auswirkungen auf die Ausbildung und Funktion von Mykorrhiza im Boden sind zu erwarten. In Nahrungswahlexperimenten zeigte Aphelenchoides sp. eine ausgeprägte Präferenz für bestimmte Pilzarten. Das Wechseln zwischen den einzelnen Pilzspezies weist auf die Bevorzugung von “Mischnahrung” hin. Dies dürfte eine Strategie zur Vermeidung von hohen Konzentrationen toxischer Nahrungsbestandteile sein. Präferenz und Nahrungsqualität standen nur in geringem Zusammenhang. Somit können auch Pilze, die eine schlechte Nahrungsquelle darstellen, attraktiv auf Nematoden wirken und deren Verbreitung in Boden und Rhizosphäre beeinflussen.

Phylogenetic analysis of fungal aquaporins provides insight into their possible role in water transport of mycorrhizal associations

Botany ◽  
2013 ◽  
Vol 91 (8) ◽  
pp. 495-504 ◽  
Author(s):  
Hao Xu ◽  
Janice E.K. Cooke ◽  
Janusz J. Zwiazek
Keyword(s):  
Water Transport ◽  
Mycorrhizal Fungi ◽  
Functional Characterization ◽  
Arbuscular Mycorrhizal ◽  
Gene Families ◽  
Fungal Species ◽  
Comparative Genomic ◽  
Mycorrhizal Associations ◽  
Insight Into

In mycorrhizal associations, water transport properties of the fungal hyphae may have a profound effect on water transport of the host plant. The importance of aquaporins, water-transporting members of the major intrinsic protein (MIP) family, in facilitating water transport has been widely acknowledged and extensively studied in plants. However, until recently, relatively little was known about the structure, function, and regulation of fungal MIPs. The rapid increase in the number of sequenced fungal genomes, including Laccaria bicolor and other mycorrhizal fungi, has enabled functional and comparative genomic investigations to delineate the role that fungal MIPs play in mycorrhizal-facilitated plant water transport. Phylogenic analysis of 229 fungal MIPs from 88 species revealed that MIPs of mycorrhizal fungal species fall into four clusters delineated by functionally characterized fungal MIPs: the orthodox aquaporins, the aquaglyceroporins, the facultative fungal aquaporins, and the X intrinsic proteins. This comparative genomics analysis, together with in silico structural characterization of predicted MIPs and recently published functional characterization of MIPs from a small number of ectomycorrhizal and arbuscular mycorrhizal species, provide new insight into MIP gene families of mycorrhizal fungi and possible roles for fungal aquaporins in water relations of mycorrhizal plant–fungus symbioses.

Influence of temperature on the mycorrhizal associations of Pinus radiata D. Don

1971 ◽  
Vol 19 (1) ◽  
pp. 13 ◽  
Author(s):  
C Theodorou ◽  
GD Bowen
Keyword(s):  
Pinus Radiata ◽  
Mycorrhizal Fungi ◽  
Linear Growth ◽  
Root Colonization ◽  
Fungal Species ◽  
Field Inoculation ◽  
Mycorrhizal Associations ◽  
Influence Of Temperature On ◽  
Soil Temperatures ◽  
Stimulate Plant Growth

The growth on Melin-Norkrans medium by 12 out of 13 isolates (five species) of mycorrhizal fungi declined rapidly between 20 and 16°C, as did colonization of the rhizosphere of Pinus radiata by four out of five isolates (three species). Mycorrhizal production in soil was optimal at 25° and declined markedly between 20 and 15°. Large differences occurred between strains within a fungal species in length of root colonized and in the intensity of growth on the root at 16°C. Extremely poor colonization by some fungi at 16° compared with 20° reveals a necessity to select fungi for field inoculation on the basis of root colonization at soil temperatures appropriate to the area and season as well as on ability to stimulate plant growth. The effect of tem- perature on the linear growth of different fungal isolates in a rich laboratory medium was a poor guide to their growth in the rhizosphere.

Rumen fermentation and food selection in East African sheep, goats, Thomson's gazelle, Grant's gazelle and impala

1977 ◽  
Vol 89 (1) ◽  
pp. 129-135 ◽  
Author(s):  
P. P. Hoppe ◽  
S. A. Qvortrup ◽  
M. H. Woodford
Keyword(s):  
Volatile Fatty Acids ◽  
Food Selection ◽  
Food Preferences ◽  
Rumen Fermentation ◽  
East African ◽  
Mean Values ◽  
Plant Parts ◽  
Marked Preference ◽  
In The Wild

SummaryThe relationship between the selected food and rumen fermentation was investigated in Thomson's gazelle, Grant's gazelle, impala and Maasai haired sheep and goats. All animals were shot in the same grass-bushland area within 1 week during the dry season.According to rumen contents, sheep were almost exclusively grazers. In goats, Thomson's gazelle and impala, grass accounted for about 70% of all plant parts identified. In Grant's gazelle, browse includingAcaciaseed constituted 68% of rumen ingesta. The two gazelle species showed a very marked preference for green grass leaves.In sheep and goat rumens, concentrations of NH3-N and volatile fatty acids, andin vitrofermentation rates (262 and 272 μmoles gasNTPD/g D.M./h, respectively) were lowest. In the wild ruminants, concentrations of fermentation end-products were higher and the rate of fermentation significantly (P< 0·05) faster, namely 420 in Thomson's gazelle, 356 in Grant's gazelle and 376 in impala. Rumen pH was not significantly different between species, with mean values ranging between 6·3 and 6·0. Total VFA concentrations ranged between 124 and 178 m-equiv/1 in the rumen and around 25 m-equiv/1 in the abomasum. Acetic acid accounted for about 75% of the total VFAs.It is concluded that there are large differences in the pattern of rumen fermentation between wild and domestic mixed-feeding ruminants which reflect their respective food preferences.

scholarly journals Propagation and reintroduction of Caladenia

2009 ◽  
Vol 57 (4) ◽  
pp. 373 ◽  
Author(s):  
Magali Wright ◽  
Rob Cross ◽  
Kingsley Dixon ◽  
Tien Huynh ◽  
Ann Lawrie ◽  
...  
Keyword(s):  
Conservation Planning ◽  
Mycorrhizal Fungi ◽  
Ex Situ ◽  
Terrestrial Orchid ◽  
Natural Habitats ◽  
Nurse Plants ◽  
Mycorrhizal Associations ◽  
Symbiotic Germination ◽  
Growing Conditions

Many Caladenia species have been reduced to extremely small and/or fragmented populations, and reintroduction/translocation into natural or rehabilitated habitats, by using ex situ propagated plants or via direct seeding, represents an important adjunct in conservation planning. However, Caladenia species are some of the most difficult terrestrial orchid taxa to propagate, in part because of the specificity of the mycorrhizal associations and the need to provide growing conditions that suit both the mycorrhizal fungi and Caladenia plants. The present paper reviews recent advances in Caladenia propagation and reintroduction methods, including in vitro seed germination, transferral from in vitro to nursery environments, ex vitro symbiotic germination (germination in inoculated nursery media), nursery cultivation, the use of nurse plants and reintroduction of Caladenia into natural habitats by using seed, dormant tubers or growing plants. Techniques discussed in the present paper increase the options for future Caladenia conservation programs, especially for those species currently on the brink of extinction.

scholarly journals Specificity of assemblage, not fungal partner species, explains mycorrhizal partnerships of mycoheterotrophic Burmannia plants

2021 ◽  
Author(s):  
Zhongtao Zhao ◽  
Xiaojuan Li ◽  
Ming Fai Liu ◽  
Vincent S. F. T. Merckx ◽  
Richard M. K. Saunders ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Fungal Species ◽  
Mycorrhizal Associations ◽  
Fungal Partner ◽  
Gradual Loss ◽  
Fungal Assemblages ◽  
Fungal Associations ◽  
Mycorrhizal Interactions ◽  
Species Specific

AbstractMycoheterotrophic plants (MHPs) growing on arbuscular mycorrhizal fungi (AMF) usually maintain specialized mycorrhizal associations. The level of specificity varies between MHPs, although it remains largely unknown whether interactions with mycorrhizal fungi differ by plant lineage, species, and/or by population. Here, we investigate the mycorrhizal interactions among Burmannia species (Burmanniaceae) with different trophic modes using high-throughput DNA sequencing. We characterized the inter- and intraspecific dynamics of the fungal communities by assessing the composition and diversity of fungi among sites. We found that fully mycoheterotrophic species are more specialized in their fungal associations than chlorophyllous species, and that this specialization possibly results from the gradual loss of some fungal groups. In particular, although many fungal species were shared by different Burmannia species, fully MHP species typically host species-specific fungal assemblages, suggesting that they have a preference for the selected fungi. Although no apparent cophylogenetic relationship was detected between fungi and plants, we observe that evolutionarily closely related plants tend to have a greater proportion of shared or closely related fungal partners. Our findings suggest a host preference and specialization toward fungal assemblages in Burmannia, improving understanding of interactions between MHPs and fungi.

Codiversification of orchids (Pterostylidinae) and their associated mycorrhizal fungi

2011 ◽  
Vol 59 (5) ◽  
pp. 480 ◽  
Author(s):  
J. Tupac Otero ◽  
Peter H. Thrall ◽  
Mark Clements ◽  
Jeremy J. Burdon ◽  
Joseph T. Miller
Keyword(s):  
Mycorrhizal Fungi ◽  
Mycorrhizal Fungus ◽  
Distinct Group ◽  
Host Group ◽  
Mycorrhizal Associations ◽  
As Species ◽  
Terrestrial Orchids ◽  
Nuclear Its ◽  
Germination Experiments

Fungal symbionts involved in mycorrhizal associations are known to vary considerably in both specificity and the level of benefits conferred on their plant hosts. For orchids, association with a suitable mycorrhizal fungus is vital for successful germination, growth and establishment. Using an evolutionarily distinct group of Australasian terrestrial orchids, the Pterostylidinae (Cranichiadeae: Orchidaceae), we assessed potential codiversification and the level of response between this diverse host group (~250 species) and their associated fungal symbionts. All fungal isolates recovered (~200 from 41 host species covering all major orchid clades) were identified as species of Ceratobasidium, which clustered into strongly supported groups using nuclear (ITS) and mitochondrial (ML 4–5) gene sequences. Three clades within the Pterostylidinae phylogeny showed associations with specific fungal clades. The results suggest the occurrence of local adaptation by the fungal symbionts to the orchid host, particularly in diverse and widespread host taxa. Results of cross-inoculation in vitro germination experiments revealed correlations between certain mycorrhizal fungal clades and particular orchid taxa, with germination generally being most effective when seeds were inoculated with fungal strains from the same clade as found naturally associated with the orchid species. We found only general congruence between the orchid and fungal phylogenies, suggesting that strict codivergerence between these orchids and their mycorrhizal associates has not occurred at the broad level of resolution studied.

scholarly journals Mycorrhizal Fungal Partners Remain Constant during a Root Lifecycle of Pleione bulbocodioides (Orchidaceae)

2021 ◽  
Vol 7 (11) ◽  
pp. 994
Author(s):  
Jiao Qin ◽  
Jing-Qiu Feng ◽  
Wei Zhang ◽  
Shi-Bao Zhang
Keyword(s):  
Mycorrhizal Fungi ◽  
Root Elongation ◽  
Temporal Dynamics ◽  
Fungal Endophytes ◽  
Resource Conservation ◽  
Fungal Species ◽  
Its2 Region ◽  
Development Stages ◽  
Mycorrhizal Associations ◽  
Temporal Turnover

Mycorrhizal mutualisms are vital for orchids through germination to adulthood. Fungal species diversity and community composition vary across seasons and plant development stages and affect plant survival, adaptation, and community maintenance. Knowledge of the temporal turnover of mycorrhizal fungi (OMF) remains poorly understood in the eco-physiologically diverse orchids (especially in epiphytic orchids), although it is important to understand the function and adaptation of mycorrhizae. Some species of Pleione are epiphytic plants with annual roots and may recruit different fungal partners during their root lifecycle. Based on continuous samplings of Pleione bulbocodioides during a whole root lifecycle, we characterized the fungal temporal dynamics using Illumina sequencing of the ITS2 region. Our data showed that the plants of P. bulbocodioides were quickly colonized by OMF at root emergence and had a constant OMF composition throughout one root lifecycle, although the OMF richness declined with root aging after a peak occurrence during root elongation. In contrast, the richness of root-inhabiting fungal endophytes kept increasing with root aging and more drastic turnovers were found in their species compositions. Our findings of OMF temporal turnover contribute to further understanding of mycorrhizal associations and adaptation of Orchidaceae and will benefit orchid resource conservation and utilization.

scholarly journals Inoculation with Ericoid Mycorrhizal Associations Alleviates Drought Stress in Lowland and Upland Velvetleaf Blueberry (Vaccinium myrtilloides) Seedlings

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2786
Author(s):  
Deyu Mu ◽  
Ning Du ◽  
Janusz J. Zwiazek
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Mycorrhizal Fungi ◽  
Fungal Species ◽  
The North ◽  
Mycorrhizal Associations ◽  
Oidiodendron Maius ◽  
Drought Survival ◽  
Vaccinium Myrtilloides

Although velvetleaf blueberry (Vaccinium myrtilloides) is usually associated with sandy (upland) areas of the North American boreal forest, lowland populations can be also found in bogs, suggesting possible adaptations to different site conditions. In this study, we examined the role of ericoid mycorrhizal (ERM) fungi in conferring drought resistance to the upland and lowland velvetleaf blueberry seedlings. The seedlings were inoculated with four ERM fungi (Pezicula ericae, Pezoloma ericae, Meliniomyces variabilis, and Oidiodendron maius) isolated from the roots of ericaceous plants and grown under controlled environmental conditions in sterilized soil. The inoculated and non-inoculated (inoculation control) plants were subsequently subjected to three cycles of drought stress by withdrawing watering. Lowland plants appeared to benefit relatively more from mycorrhizal colonization, compared with the upland plants, in terms of plant growth and drought survival. After three weeks of treatments, the dry weights of non-inoculated well-watered upland plants were higher compared to the non-inoculated lowland plants. However, these differences were offset by the inoculation of plants with ERM fungi, some of which also significantly improved drought resistance characteristics of the upland and lowland plants. There were no major differences in the effects of different ERM fungal species on drought responses of upland and lowland plants. Of the examined ericoid mycorrhizal fungi, inoculation with Pezicula ericae was the most effective in conferring drought resistance characteristics to both upland and lowland seedlings and helped maintain higher shoot water potentials, net photosynthetic, and transpiration rates in plants subjected to drought stress.

Simultaneous encapsulation of seed and mycorrhizal fungi for long-term storage and propagation of terrestrial orchids

2008 ◽  
Vol 56 (7) ◽  
pp. 609 ◽  
Author(s):  
Karen D. Sommerville ◽  
John P. Siemon ◽  
Chris B. Wood ◽  
Catherine A. Offord
Keyword(s):  
Mycorrhizal Fungi ◽  
Ex Situ Conservation ◽  
Alginate Beads ◽  
Ex Situ ◽  
Storage Duration ◽  
Long Term Storage ◽  
Mycorrhizal Associations ◽  
Terrestrial Orchids

Ex situ conservation of threatened terrestrial orchids requires the simultaneous conservation of their mycorrhizal associations. A method for encapsulating both seed and fungi in alginate beads (known as encapsulation–dehydration) was applied to the storage and propagation of two endangered orchid species in NSW, Australia—Pterostylis saxicola D.L.Jones & M.A.Clem. and Diuris arenaria D.L.Jones. We tested the effect of storage duration and temperature on fungal recovery and germination potential in vitro, and recorded survival for seedlings subsequently transferred to potting mix. Storage at 23°C significantly reduced fungal recovery and germination for both species after only 3 months (P < 0.05), whereas storage at 4°C significantly reduced fungal recovery for P. saxicola after 6 months (P < 0.05). Storage for 6 months at −18 and −196°C had no significant effect on the fungal recovery and germination percentages of either species. All beads transferred directly from in vitro culture to potting mix resulted in the establishment of at least one seedling, and production of a healthy tuberoid, when transferred near the commencement of the natural growing season. The encapsulation–dehydration method may have a practical application for use in ex situ conservation of other terrestrial orchids, as well as their mycorrhizal fungi.

scholarly journals Alkaline extract of the seaweed Ascophyllum nodosum stimulates arbuscular mycorrhizal fungi and their endomycorrhization of plant roots

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Hines ◽  
Timo van der Zwan ◽  
Kevin Shiell ◽  
Katy Shotton ◽  
Balakrishnan Prithiviraj
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Ascophyllum Nodosum ◽  
Tube Length ◽  
Direct Stimulation ◽  
Mycorrhizal Associations ◽  
Stimulation Of

AbstractAscophyllum nodosum extracts (ANE) are well-established plant biostimulants that improve stress tolerance and crop vigour, while also having been shown to stimulate soil microbes. The intersection of these two stimulatory activities, and how they combine to enhance plant health, however, remains poorly understood. In the present study, we aimed to evaluate: (1) the direct effect of ANE on the arbuscular mycorrhizal fungus Rhizophagus irregularis, and (2) whether ANE influences endomycorrhization in plants. ANE enhanced development of R. irregularis in vitro, showing greater spore germination, germ tube length, and hyphal branching. Greenhouse-grown Medicago truncatula drench-treated with ANE formed mycorrhizal associations faster (3.1-fold higher mycorrhization at week 4) and grew larger (29% greater leaf area by week 8) than control plants. Foliar applications of ANE also increased root colonization and arbuscular maturity, but did not appear to enhance plant growth. Nonetheless, following either foliar or drench application, M. truncatula genes associated with establishment of mycorrhizae were expressed at significantly higher levels compared to controls. These results suggest that ANE enhances mycorrhization through both direct stimulation of arbuscular mycorrhizal fungus growth and through stimulation of the plant’s accommodation of the symbiont, together promoting the establishment of this agriculturally vital plant–microbe symbiosis.

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