Effects of salinity stress on the germination, survival, and legume-rhizobial symbiosis of native legume Dalea purpurea
Soil salinity poses a major challenge for oil sands reclamation in Alberta. Sodium chloride is an abiotic stressor that negatively affects plants physiologically causing a need to identify native plant species capable of surviving and improving the soil conditions of these sites. Dalea purpurea (Fabaceae) is a promising candidate for oil sands reclamation, but no research has been done to assess its salinity tolerance and the effect of salinity on its Rhizobial symbiosis. In the present laboratory study, we subjected D. purpurea seedlings to pre-germination conditions of 0, 25, and 50mM NaCl, in the presence and absence of Rhizobial symbionts. We found a significant decrease in germination success and post-germination survival as a result of salinity with salt-sensitivity varying among individuals. Surviving individuals in salinity treatments displayed growth comparable to control treatments. Salinity did not affect nodulation, but significantly reduced nodule volume by 56% at 50mM NaCl. While nodule health of the species is negatively impacted by salinity, the species may be useful in salinity reclamation due to the presence of salt-tolerant individuals. This is the first study to consider the utility of native legumes and their rhizobial symbionts for the reclamation of saline oil sands sites.
Presented in absentia on April 27, 2020 at "Student Research Day" at MacEwan University in Edmonton, Alberta. (Conference cancelled)
All Rights Reserved