Department of Renewable Resources, University of Alberta, 4-42 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada.
City of Edmonton, P.O. Box 2359, Edmonton, AB, T5J 2R7, Canada.
Mycorrhiza. 2019 Jul;29(4):303-312. doi: 10.1007/s00572-019-00893-3. Epub 2019 Apr 13.
With large forested urban areas, the city of Edmonton, Alberta, Canada, faces high annual costs of replacing trees injured by deicing salts that are commonly used for winter road maintenance. Ectomycorrhizal fungi form symbiotic associations with tree roots that allow trees to tolerate the detrimental effects of polluted soils. Here, we examined mycorrhizal colonization of Pinus contorta by germinating seeds in soils collected from different locations: (1) two urban areas within the city of Edmonton, and (2) an intact pine forest just outside Edmonton. We then tested the responses of seedlings to 0-, 60-, and 90-mM NaCl. Our results showed lower abundance and diversity of ectomycorrhizal fungi in seedlings colonized with the urban soils compared to those from the pine forest soil. However, when subsequently exposed to NaCl treatments, only seedlings inoculated with one of the urban soils containing fungi from the genera Tuber, Suillus, and Wilcoxina, showed reduced shoot Na accumulation and higher growth rates. Our results indicate that local ectomycorrhizal fungi that are adapted to challenging urban sites may offer a potential suitable source for inoculum for conifer trees designated for plating in polluted urban environments.
拥有大面积森林的加拿大阿尔伯塔省埃德蒙顿市，每年因道路除冰盐（常用于冬季道路养护）而导致树木受损，需耗费大量资金用于更换树木。外生菌根真菌与树木根系形成共生关系，使树木能够耐受受污染土壤的有害影响。在这里，我们研究了 Pinus contorta 在不同地点的土壤中萌发种子时的菌根定殖情况：（1）埃德蒙顿市的两个城区，（2）埃德蒙顿市外的一片完整的松林。然后，我们测试了幼苗对 0、60 和 90mM NaCl 的反应。结果表明，与松林土壤相比，来自城区土壤的幼苗中菌根真菌的丰度和多样性较低。然而，当随后暴露于 NaCl 处理时，只有用一种含有 Tuber、Suillus 和 Wilcoxina 属真菌的城市土壤接种的幼苗，其地上部 Na 积累减少，生长速度提高。研究结果表明，适应具有挑战性的城市环境的本地外生菌根真菌可能为在污染的城市环境中指定种植的针叶树提供合适的接种体来源。
