Plant growth and ectomycorrhiza formation by transplants on deglaciated land near Exit Glacier, Alaska

Helm, D. J.; Allen, Edith B.; Trappe, James M.

doi:10.1007/s005720050250

Cited by 32 publications

(23 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The percentages of root colonization by both ecto-and ericoid mycorrhizal fungi found in our study were similar to those reported for other cold, nutrient-limited areas of the world, mainly boreal temperate forests and heathlands (Helm et al 1996(Helm et al , 1999Johansson 2000). It has been proposed that root colonization by mycorrhizal fungi decreases with increasing nutrient availability in the soil, because plants can meet their nutrient requirements through direct uptake by roots without the extra C expenditure required to support mycorrhizal fungi (Aerts and Chapin 2000).…”

Section: Discussionsupporting

confidence: 89%

Mycorrhizal colonization mediated by species interactions in arctic tundra

2003

View full text Add to dashboard Cite

The Alaskan tussock tundra is a strongly nutrient-limited ecosystem, where almost all vascular plant species are mycorrhizal. We established a long-term removal experiment to document effects of arctic plant species on ecto- and ericoid mycorrhizal fungi and to investigate whether species interactions and/or nutrient availability affect mycorrhizal colonization. The treatments applied were removal of Betula nana ( Betulaceae, dominant deciduous shrub species), removal of Ledum palustre ( Ericaceae, dominant evergreen shrub species), control (no removal), and each of these three treatments with the addition of fertilizer. After 3 years of Ledum removal and fertilization, we found that overall ectomycorrhizal colonization in Betula was significantly reduced. Changes in ectomycorrhizal morphotype composition in removal and fertilized treatments were also observed. These results suggest that the effect of Ledum on Betula's mycorrhizal roots is due to sequestration of nutrients by Ledum, leading to reduced nutrient availability in the soil. In contrast, ericoid mycorrhizal colonization was not affected by fertilization, but the removal of Betula and to a lower degree of Ledum resulted in a reduction of ericoid mycorrhizal colonization suggesting a direct effect of these species on ericoid mycorrhizal colonization. Nutrient availability was only higher in fertilized treatments, but caution should be taken with the interpretation of these data as soil microbes may effectively compete with the ion exchange resins for the nutrients released by plant removal in these nutrient-limited soils.

show abstract

Section: Discussionsupporting

confidence: 89%

Mycorrhizal colonization mediated by species interactions in arctic tundra

2003

View full text Add to dashboard Cite

show abstract

“…This has been demonstrated in studies comparing mycorrhizal species assemblages on greenhouse bioassay seedlings to those in the field (26,58). Differences in the types of species found and species richness are apparent in these comparisons (26,58), as greenhouse bioassay experiments tend to select for the more resistant propagules in the field soil (59). However, greenhouse bioassay experiments may reflect the same general trends in colonization and species richness observed in the field (60).…”

Section: Discussionmentioning

confidence: 91%

“…It has been suggested that greenhouse studies do not accurately reflect field conditions and are not adequate indicators of what might occur in more natural settings (58). This has been demonstrated in studies comparing mycorrhizal species assemblages on greenhouse bioassay seedlings to those in the field (26,58).…”

Section: Discussionmentioning

confidence: 99%

Comparisons of Ectomycorrhizal Colonization of Transgenic American Chestnut with Those of the Wild Type, a Conventionally Bred Hybrid, and Related Fagaceae Species

D'Amico

Horton

Maynard

et al. 2015

Appl Environ Microbiol

View full text Add to dashboard Cite

bAmerican chestnut (Castanea dentata [Marsh.] Borkh.) dominated the eastern forests of North America, serving as a keystone species both ecologically and economically until the introduction of the chestnut blight, Cryphonectria parasitica, functionally eradicated the species. Restoration efforts include genetic transformation utilizing genes such as oxalate oxidase to produce potentially blight-resistant chestnut trees that could be released back into the native range. However, before such a release can be undertaken, it is necessary to assess nontarget impacts. Since oxalate oxidase is meant to combat a fungal pathogen, we are particularly interested in potential impacts of this transgene on beneficial fungi. This study compares ectomycorrhizal fungal colonization on a transgenic American chestnut clone expressing enhanced blight resistance to a wild-type American chestnut, a conventionally bred American-Chinese hybrid chestnut, and other Fagaceae species. A greenhouse bioassay used soil from two field sites with different soil types and land use histories. The number of colonized root tips was counted, and fungal species were identified using morphology, restriction fragment length polymorphism (RFLP), and DNA sequencing. Results showed that total ectomycorrhizal colonization varied more by soil type than by tree species. Individual fungal species varied in their colonization rates, but there were no significant differences between colonization on transgenic and wild-type chestnuts. This study shows that the oxalate oxidase gene can increase resistance against Cryphonectria parasitica without changing the colonization rate for ectomycorrhizal species. These findings will be crucial for a potential deregulation of blight-resistant American chestnuts containing the oxalate oxidase gene. E xotic pests and pathogens in North American forests have become increasingly significant problems, resulting in economic and ecological losses (1-5). One of the most famous is the introduction of chestnut blight, caused by the fungal pathogen Cryphonectria parasitica (Murr.) Barr, that nearly brought the American chestnut (Castanea dentata [Marsh.] Borkh.) to extinction (6). Prior to the blight, American chestnut dominated eastern U.S. hardwood forests, commonly comprising more than 25% and sometimes as much as 70% of the canopy (7,8). Following its removal as a top succession canopy species, many of the chestnut's former roles in the ecosystem were disrupted, resulting in both short-term effects and long-term impacts (2, 9).Chestnut was not only important ecologically but also played a significant role in the American economy. Fast growth and high tannin content made chestnut an asset to the lumber and leather industries (10). In addition to use in the leather industry, the high level of tannins in the wood and its resistance to water penetration due to extensive tylose formation (11) make it highly rot resistant and ideal for uses such as telephone poles, railway ties, and fencing (10, 12). American chestnut wood also was use...

show abstract

“…Percentage ECM colonization was calculated as the number of ECM root tips divided by the total number of root tips [19]. Percent colonization for each ECM morphotype was calculated for each sampled tree by dividing the number of root tips of each ECM type by the total number of root tips, and multiplying by 100 [24].…”

Section: Quantificationmentioning

confidence: 99%

Ectomycorrhizal colonization of Alnus acuminata Kunth in northwestern Argentina in relation to season and soil parameters

et al. 2005

View full text Add to dashboard Cite

-The objective of this study was to determine patterns of ECM colonization of Andean alder at two natural forests in relation to soil parameters at two different seasons (autumn and spring). The soil parameters studied were field capacity, pH, electrical conductivity, available P, total N and organic matter. Twelve ECM morphotypes were found on A. acuminata roots. The ECM colonization varied among soil types and was affected positively by electrical conductivity. Multiple regression relationships among ECM colonization and edaphic properties variables showed no significant differences at two seasons and among soil types with respect to morphotype diversity values. Positive correlations were found between three morphotypes (Cortinarius tucumanensis, Gyrodon monticola and Russula alnijorrulensis) and soil types and two other morphotypes (Naucoria escharoides and Lactarius sp.) between two seasons. Results of this study provide evidence that ECM colonization of A. acuminata is affected by some chemical edaphic parameters and indicate that some ECM morphotypes are sensitive to changes in seasonality and soil parameters.Alnus acuminata / ectomycorrhizal diversity / Andean forest / soil type Résumé -Colonisation ectomycorrhizienne d'Alnus acuminata Kunth au nord-ouest de l'Argentine en relation avec la saison et quelques paramètres du sol. Le but de cette étude était de déterminer, au cours de deux différentes saisons (août et printemps), les modèles de colonisation de l'aulne andin dans deux forêts naturelles en relation avec quelques paramètres de sol. Les paramètres de sol étudiés étaient la capacité au champ, le pH, la conductivité électrique, le P disponible, le N total et la matière organique. Douze morphotypes de ECM ont été trouvés sur des racines de A. acuminata. La colonisation par les ECM varie en fonction des types de sols et est affectée positivement par la conductivité électrique. Les relations de régression multiple entre la colonisation de ECM et les variables de propriétés du sol n'ont montré aucune différence significative entre les deux saisons et entre les types de sol pour ce qui concerne des valeurs de diversité morphotypique. Des corrélations positives existent entre Cortinarius tucumanensis, Gyrodon monticola et Russula alnijorrulensis et les types de sol, et entre Naucoria escharoides et Lactarius sp. et les deux saisons. Les résultats de cette étude mettent en évidence que la colonisation de ECM de A. acuminata est affectée par quelques paramètres édaphiques chimiques et indiquent que quelques morphotypes de ECM sont sensibles aux changements des paramètres saisonniers et pédologiques.Alnus acuminata / diversité ectomycorrhizienne / forêt Andine / type de sol

show abstract

Plant growth and ectomycorrhiza formation by transplants on deglaciated land near Exit Glacier, Alaska

Cited by 32 publications

References 19 publications

Mycorrhizal colonization mediated by species interactions in arctic tundra

Mycorrhizal colonization mediated by species interactions in arctic tundra

Comparisons of Ectomycorrhizal Colonization of Transgenic American Chestnut with Those of the Wild Type, a Conventionally Bred Hybrid, and Related Fagaceae Species

Ectomycorrhizal colonization of Alnus acuminata Kunth in northwestern Argentina in relation to season and soil parameters

Contact Info

Product

Resources

About