GROWTH AND DEVELOPMENT OF MYCORRHIZAE OF SUGAR MAPLE (ACER SACCHARUM MARSH.)

1966 ◽  
Vol 44 (10) ◽  
pp. 1413-1425 ◽  
Author(s):  
Kenneth J. Kessler

Beaded rootlet growth in Acer saccharum is thought to be caused by intermittent growth due to alternately favorable and unfavorable moisture conditions during the season rather than by mycorrhizal infection. Both beaded and nonbeaded rootlets are mycorrhizal-infected, and rootlets growing in the deeper soil levels where moisture conditions do not fluctuate rapidly are nonbeaded. Differences found in the activity of rootlets growing in hummocks and depressions appeared to be related to soil moisture conditions found there. This paper describes (a) the anatomy of metacutinized root tips during dry soil conditions, and the relationship of this condition to the development of constrictions between beads; (b) the extrastelar anatomical characteristics of beaded and nonbeaded rootlets; (c) the morphology of the mycorrhizal fungus in its relationship to rootlet anatomy; (d) the extramatrical mycelium of the mycorrhizal fungus found in the soil of the rooting zone (the extramatrical mycelium is thought to arise from fungal hyphae and vesicles produced in live rootlets which are released to the soil from disintegrating rootlet cortical tissue); and (e) an hypothesis regarding the life history of this type of vesicular–arbuscular mycorrhizal fungus.

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 186 ◽  
Author(s):  
Wei-Qin Gao ◽  
Li-Hui Lü ◽  
A. Srivastava ◽  
Qiang-Sheng Wu ◽  
Kamil Kuča

A potted experiment was carried out to evaluate the effect of an arbuscular mycorrhizal fungus (AMF), Acaulospora scrobiculata, on peach seedlings grown in non-replant (NR) and replant (R) soils, to establish whether AMF inoculation alleviated soil replant disease through changes in physiological levels and relevant gene expression. After 15 weeks of mycorrhization, root mycorrhizal colonization was heavily inhibited by R treatment versus NR treatment. AMF plants under NR and R soil conditions displayed significantly higher total plant biomass than non-AMF plants. AMF inoculation significantly increased root sucrose and fructose concentrations and root catalase, peroxidase, polyphenol oxidase, and phenylalanine ammonialyase activities under R conditions. Likewise, salicylic acid, jasmonic acid, chitinase, total soluble phenol, and lignin concentrations in roots were significantly higher in AMF than in non-AMF seedlings grown in R soil. Over-expression of PpCHI, PpLOX1, PpLOX5, PpAOC3, PpAOC4, and PpOPR2 in roots was observed in AMF-inoculated seedlings, as compared to that of non-AMF-inoculated seedlings grown in R soils. Thus, mycorrhizal fungal inoculation conferred a greater tolerance to peach plants in R soil by stimulating antioxidant enzyme activities, disease-resistance substance levels, and the expression of relevant genes.


2000 ◽  
Vol 30 (10) ◽  
pp. 1543-1554 ◽  
Author(s):  
Andrew P Coughlan ◽  
Yolande Dalpé ◽  
Line Lapointe ◽  
Yves Piché

Acer saccharum Marsh. (sugar maple) is one of only few arbuscular mycorrhizal trees to form extensive stands in northern temperate biomes. Recent maple decline could result from altered intensity and quality of root colonization by associated mycobionts or possible shifts in symbiotic fungal community composition following environmental stresses. In this study the effects on arbuscular mycorrhizal fungi of soil acidification, one of several proposed causal stresses underlying forest decline, and remedial liming were investigated under glasshouse conditions. Acer saccharum seedlings were grown in unsterilized, pH altered, forest soils from healthy and declining maple stands. Over a range of treatment pHs normally tolerated by A. saccharum, fungal populations and responses to pH changes differed between the two soils. The declining site with more acidic soil had an initially larger spore population but lower taxonomic diversity than the healthy site. However, liming stimulated sporulation of several taxa initially apparently absent from the declining site spore population. The quantity of colonization generally increased with pH for both sites. Five Glomus taxa and Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders are added to the list of fungi known to form arbuscular mycorrhizas with A. saccharum, and the known range of Acaulospora cavernata Blaszkowski is extended from Poland to eastern North America.


2011 ◽  
Vol 41 (4) ◽  
pp. 873-880 ◽  
Author(s):  
Dominique Gravel ◽  
Marilou Beaudet ◽  
Christian Messier

Northern hardwoods have undergone a marked change in their dynamics, with American beech ( Fagus grandifolia Ehrh.) increasing in abundance relative to sugar maple ( Acer saccharum Marsh.). This study aims to better understand this sudden shift in recruitment dynamics. We performed an extensive analysis of the age structure, radial growth pattern, and release history on >700 saplings from 34 mature maple–beech stands of southern Quebec. We found (i) that the sapling age structures showed a progressive decrease in the establishment of maple relative to beech starting about 40 years ago, (ii) a change in the species growth hierarchy that started in the 1980s due to increasing radial growth of beech, (iii) that this growth trend is negligible for both maple and beech when we account for size and suppression status, and finally (iv) that the growth trend appears to be independent of present soil conditions. These results contrast with previous studies conducted at the adult stage that reported a growth decline for maple. We conclude that this change in recruitment dynamics is not related to growth, and consequently, further studies investigating this phenomenon should concentrate on establishment and survival.


2010 ◽  
Vol 40 (2) ◽  
pp. 385-393 ◽  
Author(s):  
Matthew C. Kwit ◽  
Lesley S. Rigg ◽  
David Goldblum

Using in situ light curves and understory seasonal light measurements the importance of canopy avoidance was evaluated for a population of sugar maple ( Acer saccharum Marsh.) seedlings living at the boreal ecotone in Lake Superior Provincial Park, Ontario, Canada. At higher latitudes, the time period associated with canopy avoidance is shorter and occurs at cooler temperatures, increasing the risk of frost damage. In 2008, leaf-out began 5 days prior to the last frost of the season. By modeling the potential carbon gain of seedlings, it is clear that the short time period prior to canopy leaf-out still contributes a disproportionate amount of carbon to the overall budget of seedlings. Of the total seasonal carbon gain, 80.6% was assimilated in the initial 15 days following sugar maple seedling leaf-out. Based on our model, by leafing out only 6 days earlier than the average seedling leaf-out date, ∼200% more carbon could be assimilated during the course of the growing season. Vegetation phenology is cued by climatic triggers — as climate changes so too will phenological responses. These mechanisms add to the overall carbon budget of seedlings; recognizing these mechanisms is essential to thoroughly understand the natural history of this species.


1993 ◽  
Vol 71 (11) ◽  
pp. 1421-1426 ◽  
Author(s):  
Margaret A. Cooke ◽  
Paul Widden ◽  
Ivan O'Halloran

The development, condition, and incidence of vesicular–arbuscular mycorrhizae of Acer saccharum (sugar maple) seedlings grown in the greenhouse in natural sugar maple forest soil substrate were examined. The effects of the addition of a cation mixture containing calcium, magnesium, and potassium were also studied. The mycorrhizal structures observed were similar to those found in natural field conditions. Mycorrhizae developed intracellularly via hyphal coils, and arbuscules usually developed from these coils, forming arbusculate coils. This development is different from that observed in most annual crop plants. Vesicular–arbuscular mycorrhizal structures appeared within 30 days. The rate of mycorrhizal infection decreased, along with plant health, as the quantity of the added cations was increased, but the amendment did not affect the morphology of the infection. More vesicles were observed in the lowest level of application than in controls, suggesting a stress response and possible relationship between plant health and condition of the mycorrhizal association. Key words: Acer saccharum, development, vesicular–arbuscular mycorrhizae.


2001 ◽  
Vol 79 (8) ◽  
pp. 879-885
Author(s):  
M Filion ◽  
M St-Arnaud ◽  
C Guillon ◽  
C Hamel ◽  
S H Jabaji-Hare

Various experimental systems have been developed to study the mycorrhizosphere. In this study, a microcosm experimental system was constructed and optimized to simulate the environments of the mycorrhizosphere: the rhizosphere, the mycosphere, and the bulk soil, using beans (Phaseolus vulgaris L.) as host plants. We investigated, in a time-course study, the effect of axenically in vitro produced spore inoculum and root segment inoculum of the arbuscular mycorrhizal fungus, Glomus intraradices Schenck & Smith, on extraradical mycelium development, rapidity of mycorrhizal colonization, and plant growth under nonsterile soil conditions. Three concentrations of in vitro produced spores and three concentrations of root segment inoculum produced from open pot cultures were used. The two highest concentrations of spores used as inoculum resulted in faster and more abundant colonization than when root segments were used. A significant correlation was obtained between hyphal densities present in the rhizosphere and mycosphere compartments, and the amount of spore inoculum used. The densities of roots in the rhizosphere compartment and hyphae in the rhizosphere and mycosphere compartments were comparable with field-grown plants; thus, the system realistically mimics a natural mycorrhizosphere. The use of the microcosm described in this study, in combination with the in vitro produced spore inoculum of G. intraradices, represents an experimental approach well adapted for studying the microbial ecology of the mycorrhizosphere.Key words: AMF, microbial ecology, inoculum, mycorrhiza, mycorrhizosphere.


2010 ◽  
Vol 27 (11) ◽  
pp. 2474-2486 ◽  
Author(s):  
H. C. den Bakker ◽  
N. W. VanKuren ◽  
J. B. Morton ◽  
T. E. Pawlowska

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