Effects of Ericoid Mycorrhizal Fungi on Growth and Salt Tolerance of Blueberry (Vaccinium myrtilloides), Lingonberry (Vaccinium vitis-idaea), and Labrador tea (Rhododendron groenlandicum): Implications for Oil Sands Reclamation

• Author / Creator

  Fadaei, Sepideh

• Oil sands mining can have negative environmental impacts in the boreal forest region of northern Alberta, Canada. The Government of Alberta requires the companies to reclaim disturbed lands after mine sites are closed. The initial steps in oil sands mining operations involve the removal of forest vegetation and the topsoil, which is commonly stockpiled for several years. Stockpiling can have negative impact on the reclaimed oil sands soils through decreasing the composition and abundance of soil microorganisms and changing soil physical and chemical properties. Moreover, the presence of high concentration of dissolved Na+ and Cl- in the soil can negatively affect plant growth in the reclamation areas. This thesis project consists of two research studies. In the first study, I examined the ericoid mycorrhizal fungi (ERM) colonization potential between fresh and one-year stockpiled topsoil from the oil sands reclamation site. I also examined effects of the topsoil on growth and physiological parameters in blueberry (Vaccinium myrtilloides), Labrador tea (Rhododendron groenlandicum) and lingonberry (Vaccinium vitis-idaea) plants. Using the DNA identification method, I found that ERM colonization potential of fresh topsoil is higher than that of the topsoil that was stockpiled for one year. My results also demonstrated that blueberry and Labrador tea plants growing in fresh topsoil had higher root and shoot dry weights and higher root colonization intensity compared to the stockpiled topsoil. Concentrations of leaf chlorophyll, P, and N in blueberry plants were also lower in the stockpiled topsoil compared to the fresh soils. Soil stockpiling did not affect net photosynthesis (Pn) and transpiration rates in any plant species. The results of this experiment indicate that the stockpiled soil was less suitable as a growth substrate compared with the fresh soils for the growth of some ericaceous plants.
  In the second study, blueberry, Labrador tea and lingonberry plants were inoculated with Oidiodendron maius (Om) and Meliniomyces variabilis (Mv) ERM fungi and subjected to none (control) or 30 mM NaCl treatments for four weeks. In control blueberry and lingonberry, Pn was significantly higher in plants inoculated with O. maius compared with the non-inoculated plants. The 30 mM NaCl treatment decreased Pn and this decrease was greater in non-inoculated plants compared with those inoculated with both ERM fungi. In all three plant species, Pn of the non-inoculated plants subjected to NaCl treatment was reduced to negative values. Control blueberry plants that were inoculated with O. maius had higher total plant dry weights compared with non-inoculated plants. In Labrador tea, inoculation with M. variabilis resulted in the highest total plant dry weights. The inoculation of lingonberry plants with both species of ERM fungi prevented the total dry weight reduction by the NaCl treatment. In all three plant species, both inoculation treatments resulted in higher leaf chlorophyll concentrations compared with non-inoculated plants. The overall effect of ERM inoculation on NaCl tolerance was especially pronounced in lingonberry.
  The results of both studies point to the importance of ERM for the revegetation of oil sands reclamation sites with some ericaceous plants.

• Subjects / Keywords

  • Ericoid mycorrhizal fungi
  • Stockpiling soil
  • Ericaceous plants
  • Salt stress

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-t4cm-2t36

• License

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