Department of Renewable Resources, University of Alberta, 4-42 Earth Sciences Building, Edmonton, Alberta, T6G 2E3, Canada.
Imperial Oil Resources Ltd., Calgary Research Centre, 9223 23rd Street SE, Calgary, AB, T2C 5R2, Canada.
Mycorrhiza. 2020 Jul;30(4):419-429. doi: 10.1007/s00572-020-00958-8. Epub 2020 May 3.
To examine the effects of ericoid mycorrhizal (ERM) fungi on salt tolerance of ericaceous plants, we inoculated roots of velvetleaf blueberry (Vaccinium myrtilloides), Labrador tea (Rhododendron groenlandicum), and lingonberry (Vaccinium vitis-idaea) with ericoid mycorrhizal fungi Oidiodendron maius and Meliniomyces variabilis. Plants were subjected to 0 (NaCl control) and 30 mM NaCl treatments, and plant dry weights, gas exchange, and leaf chlorophyll concentrations were compared in inoculated and non-inoculated plants. M. variabilis increased root dry weights in all three species of NaCl-treated plants, and O. maius enhanced root dry weights of lingonberry plants treated with NaCl. Both fungal species were especially effective in enhancing root and shoot dry weights in control (0 mM NaCl) and NaCl-treated lingonberry seedlings. Leaf chlorophyll concentrations were enhanced by fungal inoculation in all three plant species, and this effect persisted under salt stress in Labrador tea and lingonberry. Salt treatment drastically reduced transpiration rates (E) and lowered net photosynthesis (Pn) to the negative values in all three species of non-inoculated plants, and this effect was partly or almost completely reversed by the inoculation with O. maius and M. variabilis. Fungal inoculation was especially effective in reducing NaCl effects on Pn in lingonberry. Oidiodendron maius and M. variabilis were also equally effective in reversing NaCl-induced declines of E in velvetleaf blueberry and lingonberry. However, in Labrador tea, O. maius reversed the decline of E in NaCl-treated plants less compared with M. variabilis resulting in high photosynthetic water use efficiency values. The results support the hypothesis that, similarly to arbuscular mycorrhizal and ectomycorrhizal associations, ERM association increases salt tolerance of plants.
为了研究内生菌根（ERM）真菌对石南科植物耐盐性的影响，我们用内生菌根真菌 Oidiodendron maius 和 Meliniomyces variabilis 接种了蔓越莓蓝莓（ Vaccinium myrtilloides ）、拉布拉多茶（ Rhododendron groenlandicum ）和越橘（ Vaccinium vitis-idaea ）的根系。将植物分别置于 0（NaCl 对照）和 30 mM NaCl 处理下，比较接种和未接种植物的植株干重、气体交换和叶片叶绿素浓度。M. variabilis 增加了所有三种 NaCl 处理植物的根系干重，而 O. maius 增强了 NaCl 处理越橘植物的根系干重。这两种真菌在对照（0 mM NaCl）和 NaCl 处理的越橘幼苗中均特别有效地增强了根系和地上部分的干重。真菌接种提高了所有三种植物的叶片叶绿素浓度，并且这种效应在 Labrador tea 和越橘的盐胁迫下仍然存在。盐处理使所有三种非接种植物的蒸腾速率（E）大幅降低，并使净光合速率（Pn）降至负值，而 O. maius 和 M. variabilis 的接种部分或几乎完全逆转了这种效应。真菌接种特别有效地降低了 NaCl 对越橘 Pn 的影响。O. maius 和 M. variabilis 也同样有效地逆转了 NaCl 诱导的 E 在蔓越莓和越橘中的下降。然而，在 Labrador tea 中，O. maius 逆转 NaCl 处理植物中 E 下降的效果不如 M. variabilis，导致高光合用水效率值。研究结果支持这样一种假设，即与丛枝菌根和外生菌根类似，内生菌根共生体增加了植物的耐盐性。
