Poster: Plant-symbiont interactions

Abs # 590: Responses to salt stress of boreal conifers infected with native ectomycorrhizal fungi

Presenter:	Nguyen, Hai TB, hain@ualberta.ca
Authors	Nguyen, Hai TB (A)   Zwiazek, Janusz  (A)
Affiliations:	(A): University of Alberta, Department of Renewable Resources

We studied the effects of NaCl and Na₂SO₄ salts on three dominant boreal conifers: Picea mariana, Picea glauca, and Pinus banksiana infected with either Hebeloma crustuniliforme (HC) or Laccaria bicolor (LB) ectomycorrhizae. At 20 weeks old, all plant species showed marked increases in salt accumulation in plant tissues and significant decreases in dry-weights and gas exchange under both salt treatments. Ectomycorrhizal treatments had no significant growth effects on Pinus mariana, positive effects on P. glauca, and negative effects on Pinus banksiana. Compared to non-infected seedlings, plant dry-weights of Picea glauca treated with HC increased 25, 27, and 20%, and those treated with LB increased 36, 13, and 32%, respectively in control, Na₂SO₄, and NaCl salt treatments. On the other hand, plant dry-weights of Pinus banksiana seedlings both HC- and LB-treated were reduced significantly compared to those untreated regardless of salt treatments. Picea mariana seedlings showed no differences in growth response to ectomycorrhizal treatments. Photosynthesis and transpiration significantly decreased due to salt treatments, especially NaCl, and the infection of either HC or LB improved photosynthesis and transpiration in Picea mariana and Pinus banksiana. The effects of salt and ectomycorrhizae treatments were variable for Picea glauca. In all plant species, treatments of both NaCl and Na₂SO₄ increased tissue salt accumulations, while HC or LB decreased tissue salt accumulations, regardless of salt treatments. Our results showed that the application of HC and LB proved to be a potentially effective tool in the amendment of saline soils, particularly where Picea glauca is being considered in the remediation plan.