scholarly journals Spore communities of arbuscular mycorrhizal fungi and mycorrhizal associations in different ecosystems, south Australia

2002 ◽  
Vol 26 (3) ◽  
pp. 627-635 ◽  
Author(s):  
Z. I. Antoniolli ◽  
E. Facelli ◽  
P. O'Connor ◽  
D. Miller ◽  
K. Ophel-Keller ◽  
...  

Communities of arbuscular mycorrhizal fungi (AMF) were surveyed in different South Australian ecosystems. The soil was wet-sieved for spore extraction, followed by the determination of presence and abundance of AMF species as well as the percentage of root colonization. Mycorrhizal associations were common and there was substantial fungal diversity in different ecosystems. Spores were most abundant in the permanent pasture system and less abundant under continuous wheat. The incidence of mycorrhizal associations in different plant species and the occurrence of Arum and Paris type colonization generally conformed with previous information. Spores of seventeen AMF were verified throughout seasonal changes in 1996 and 1997 in the permanent pasture and on four host species (Lolium perenne, Plantago lanceolata, Sorghum sp. and Trifolium subterraneum) , set up with the same soils under greenhouse conditions. Glomus mosseae was the dominant spore type at all sampling times and in all trap cultures. Mycorrhizal diversity was significantly affected by different sampling times in trap cultures but not in field-collected soil. P. lanceolata, Sorghum sp. and T. subterraneum as hosts for trap cultures showed no differences in richness and diversity of AMF spores that developed in association with their roots. Abundance and diversity were lowest, however, in association with L. perenne , particularly in December 1996. Results show that the combination of spore identification from field-collected soil and trap cultures is essential to study population and diversity of AMF. The study provides baseline data for ongoing monitoring of mycorrhizal populations using conventional methods and material for the determination of the symbiotic effectiveness of AMF key members.

2005 ◽  
Vol 71 (11) ◽  
pp. 6673-6679 ◽  
Author(s):  
David Roesti ◽  
Kurt Ineichen ◽  
Olivier Braissant ◽  
Dirk Redecker ◽  
Andres Wiemken ◽  
...  

ABSTRACT Spores of the arbuscular mycorrhizal fungi (AMF) Glomus geosporum and Glomus constrictum were harvested from single-spore-derived pot cultures with either Plantago lanceolata or Hieracium pilosella as host plants. PCR-denaturing gradient gel electrophoresis analysis revealed that the bacterial communities associated with the spores depended more on AMF than host plant identity. The composition of the bacterial populations linked to the spores could be predominantly influenced by a specific spore wall composition or AMF exudate rather than by specific root exudates. The majority of the bacterial sequences that were common to both G. geosporum and G. constrictum spores were affiliated with taxonomic groups known to degrade biopolymers (Cellvibrio, Chondromyces, Flexibacter, Lysobacter, and Pseudomonas). Scanning electron microscopy of G. geosporum spores revealed that these bacteria are possibly feeding on the outer hyaline spore layer. The process of maturation and eventual germination of AMF spores might then benefit from the activity of the surface microorganisms degrading the outer hyaline wall layer.


2015 ◽  
Vol 396 (1-2) ◽  
pp. 369-380 ◽  
Author(s):  
Haiyang Zhang ◽  
Waldemar Ziegler ◽  
Xingguo Han ◽  
Susan Trumbore ◽  
Henrik Hartmann

Mycorrhiza ◽  
2001 ◽  
Vol 10 (6) ◽  
pp. 267-273 ◽  
Author(s):  
A. Nakano ◽  
Kazushi Takahashi ◽  
Roger T. Koide ◽  
M. Kimura

1997 ◽  
Vol 75 (2) ◽  
pp. 320-332 ◽  
Author(s):  
R. E. Koske ◽  
J. N. Gemma ◽  
N. Jackson

Small plots of highly maintained turfs of creeping bentgrass (Agrostis palustris cv. Penncross) and velvet bentgrass (Agrostis canina cv. Kingstown) and a marginally maintained stand of annual bluegrass (Poa annua) were sampled intensively over a 15-month period to measure the populations of spores of arbuscular mycorrhizal fungi (AMF) associated with their root systems. Direct isolation of spores and trap cultures were used to assess the AMF communities. Spores of more than 18 species of AMF were isolated. The six dominant species (as measured by the abundance and frequency of occurrence of spores) were Acaulospora mellea, an undescribed species of Acaulospora, Scutellospora calospora, Glomus occultum, Glomus etunicatum, and Entrophospora infrequens. Spores of 17 species of AMF were recovered from the root zones of velvet bentgrass, 15 species from creeping bentgrass, and 14 from annual bluegrass. Soil fertility differed among the three sites, and it was not possible to ascribe differences in the AMF communities in each plot to any particular variable (e.g., host, pH, soil P). Average spore abundance was greatest in the creeping bentgrass plot (191.0 spores/100 mL), next in the velvet bentgrass plot (82.4 spores/100 mL), and least in the bluegrass plot (28.4 spores/100 mL). Spores were recovered from a significantly greater percentage of the samples from the bentgrass plots (88.5 – 96.8%) than from the bluegrass plot (76.6%). Spores of an average of 4.5 species of AMF were isolated monthly from creeping bentgrass, 3.3 from velvet bentgrass and 2.0 from bluegrass. Average species richness and spore abundance were positively correlated in the creeping bentgrass and bluegrass plots (r = 0.77, p = 0.001, and r = 0.68, p = 0.006), but not in the velvet bentgrass plot. Spore abundance showed strong seasonal trends in all three plots (p = 0.03 – 0.001), with numbers increasing from spring until November. Richness and abundance declined from December until the following spring. In the bluegrass area, which experienced summer drought, spore populations and richness also showed a precipitous decline in July and August in the 1st year of the study (1990), but not in the 2nd year (1991). No such summer decline occurred in the bentgrass plots that received irrigation. The AMF community that was circumscribed by direct spore counts from the field usually was highly dissimilar to the community that was estimated by trap cultures initiated using soil from the turf areas. Key words: annual bluegrass, arbuscular mycorrhizal fungi, creeping bentgrass, putting greens, turfgrass, velvet bentgrass.


2021 ◽  
Vol 12 ◽  
Author(s):  
Stephan Unger ◽  
Franziska M. Habermann ◽  
Katarina Schenke ◽  
Marjan Jongen

Arbuscular mycorrhizal fungi (AMF) may affect competitive plant interactions, which are considered a prevalent force in shaping plant communities. Aiming at understanding the role of AMF in the competition between two pasture species and its dependence on soil nutritional status, a pot experiment with mycorrhizal and non-mycorrhizal Lolium multiflorum and Trifolium subterraneum was conducted, with manipulation of species composition (five levels), and nitrogen (N)- and phosphorus (P)- fertilization (three levels). In the non-mycorrhizal state, interspecific competition did not play a major role. However, in the presence of AMF, Lolium was the strongest competitor, with this species being facilitated by Trifolium. While N-fertilization did not change the competitive balance, P-fertilization gave Lolium, a competitive advantage over Trifolium. The effect of AMF on the competitive outcome may be driven by differential C-P trade benefits, with Lolium modulating carbon investment in the mycorrhizal network and the arbuscule/vesicle ratio at the cost of Trifolium.


2002 ◽  
Vol 82 (3) ◽  
pp. 272-278 ◽  
Author(s):  
A. Liu ◽  
C. Hamel ◽  
A. Elmi ◽  
C. Costa ◽  
B. Ma ◽  
...  

Little attention has been paid to the effect of arbuscular mycorrhizal (AM) fungi on the uptake of nutrients that move mainly by mass flow. The objective of this study was to assess the possible contribution of indigenous AM fungi to the K, Ca and Mg nutrition of maize (Zea mays L.) as influenced by soil P levels and its impact on plant dry mass. The field experiment had a split plot design with four replicates. Treatments included soil fumigation status (fumigation and non-fumigation) and three levels of P fertilization (0, 60 and 120 kg P2O5 ha-1) in a loamy sand soil in 1997 and a fine sandy loam soil in 1998. Soil fumigati on with Basamid® was used to suppress indigenous AM fungi. Plants were sampled at four different growth stages (6-leaf stage, 10-leaf stage, tasseling and silking). Soil fumigation decreased shoot dry weight, but P fertilization increased shoot dry weight at most sampling times. When no P fertilizer was added, fumigation in the loamy sand soil reduced shoot K and Ca concentrations while, in contrast, in the fine sandy loam soil only Mg concentration was reduced by soil fumigation. The concentration of K in maize shoots was positively correlated (P < 0.05) with extraradicular hyphal length in both soils. The correlation between the abundance of extraradicular hyphae and the concentrations of Ca and Mg in maize shoots was significant only for soils where available Ca or Mg was relatively low. Arbuscular mycorrhizal fungi could increase corn biomass production and K, Ca and Mg uptake in soil low in these elements and low in P. These results indicate that the contribution of mycorrhizae to maize K, Ca and Mg nutrition can be significant in a field situation and that the extent of this contribution depends on the availability of these nutrients and of P in soils. Key words: Arbuscular mycorrhizal fungi, soil fumigation, extraradicular hyphae, uptake of K, Ca, and Mg, soil P levels, maize


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