<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>32</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bois, Grégory</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Écophysiologie de semis de conifères ectomycorhizés en milieu salin et sodique</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">fungi</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://theses.ulaval.ca/archimede/fichiers/23048/23048.html</style></url></web-urls></urls><pub-location><style face="normal" font="default" size="100%">Université Laval</style></pub-location><volume><style face="normal" font="default" size="100%">Foresterie et géodésie</style></volume><language><style face="normal" font="default" size="100%">FR</style></language><abstract><style face="normal" font="default" size="100%">Salinity and sodicity are major concerns for the reclamation of sand tailings originating from the open-pit mining of oil sand ores in Northeastern Alberta (Canada). Ectomycorrhizal (ECM) fungi are known to reduce certain abiotic stresses affecting their host. These fungi are naturally associated with conifers used for reclamation. The present thesis depicts the physiological response of the ECM symbiosis under controlled sodic conditions. This serves to promote integration of controlled mycorrhization in tree nurseries within revegetation programs for salt-affected sites.

In a first step, a bait experiment was performed on materials constituting reconstructed soil and on undisturbed samples of reconstructed soil of different ages. This served to assess the mycorrhizal inoculum potential present on sites to reclaim at Syncrude Canada Ltd. (Alberta). There were not any viable propagules of ECM fungi on tailing sands. In addition, the peat moss used as amendment for tailing sands exhibited a weak ECM inoculum potential and a low ECM fungal species diversity.

In a second step, (ecto- and ectendo-) mycorrhizal fungi isolated from a sodic site or selected within a fungal collection, i.e., Hymenoscyphus sp., Phialocephala sp., Suillus tomentosus (Kauff.) Sing., Snell and Dick, Laccaria bicolor (Maire) Orton, Hebeloma crustuliniforme (Bull) Quel., were subjected to a gradient of NaCl concentrations. All fungal species exhibited a strong resistance. Nevertheless, species isolated from a sodic site showed a higher growth and a lower Na+ et Cl- accumulation in their tissues under sodic conditions.

In a third step, three ECM species, L. bicolor, H. crustuliniforme and S. tomentosus, were used in greenhouse experiment in association with jack pine (Pinus banksiana Lamb.) and white spruce (Picea glauca (Moench) Voss) seedlings. These symbiotic combinations were exposed to a gradient of NaCl concentrations and showed that inoculation of ECM fungi can enhance growth and reduce the stress perceived by the host in saline and sodic conditions.

The S. tomentosus isolate was shown to be the most interesting fungus for inoculation of tree-nursery seedlings used for revegetation of saline and/or sodic sites. Hebeloma crustuliniforme UAMH 5247 was a second choice for highly affected sites as it stimulates osmotic adjustment of its host.</style></abstract><issue><style face="normal" font="default" size="100%">Ph. D. </style></issue><custom1><style face="normal" font="default" size="100%">Forestry</style></custom1><custom2><style face="normal" font="default" size="100%">des stables bitumineux dans le Nord-Est de l'Alberta</style></custom2><custom3><style face="normal" font="default" size="100%">http://www.worldcat.org/oclc/145756039</style></custom3><custom4><style face="normal" font="default" size="100%">Science</style></custom4></record></records></xml>