Abstract Detail

Biotic and abiotic stress

Shao, Jianfei [1], Renault, Sylvie [2], Markham, John [3].

Effects of salinity on the nitrogen fixing boreal shrub (Elaeagnus commutata).

Soil salinity is a major abiotic stress that reduces the growth and survival of most plants. In Canada, salinity could have potential to pose reclamation challenge in some reconstructed landscapes in the oil sand region. The use of nitrogen-fixing species such as wolf willow (Elaeagnus commutata), a native boreal shrub known for having rapid growth, adapted to nutrient limitation and drought stress has great potential for reclamation of salt disturbed habitats. We hypothesized that although higher salinity may reduce the plant physiological functions and biomass, plants inoculated with nitrogen fixing Frankia sp. will display higher rates of growth under salinity. We tested this hypothesis by setting up hydroponic systems containing wolf willow seedlings (uninoculated or inoculated with Frankia bacteria) in a greenhouse under controlled conditions. The salts were added to the nutrient solution (constantly cycled through the hydroponic systems with submersible pumps) as 0, 50 or 100 mM NaCl. Leaf photosynthesis, transpiration, chlorophyll fluorescence, relative water content and water potential were measured after 1, 4, and 8 weeks of salt treatments. Higher salt levels reduced plant photosynthesis only in the first week; however, the reduction in transpiration and stomatal conductance for salt treated plants persisted throughout the span of 8 weeks. Higher levels of salt reduced leaf water potential in the later stage of salt treatment (week 4 and 8).Inoculation with Frankia bacteria did not affect any of the physiological parameters measured in both absence and presence of salts. Harvesting of all plant tissues will take place 12 weeks after salt treatments. Root and shoot dry biomass will be determined for all plants. Harvested leaf tissues will be used for cation (K⁺, Na⁺, Ca²⁺) and Cl^- analyses, as well as analysis of proline and soluble carbohydrate contents to determine the level of osmotic adjustment by the salt-treated plants. The implications of the results obtained will be discussed.

1 - University of Manitoba, Department of Biological Sciences, 212B Biological Sciences Bdg, Winnipeg, MB, R3T 2N2, Canada
2 - University of Manitoba, Biological Sciences, 212B Biological Sciences Bdg, Winnipeg, MB, R3T2N2, Canada
3 - University of Manitoba, Biological Sciences, Winnipeg, MB, R3T 2N2, CA

Keywords:
salt stress
Land reclamation
Soil salinity
plant physiology
Salt tolerance
Abiotic stress
Nitrogen fixation
Actinorhizal plants
Frankia symbiosis
nodulation
Nitrogen Fixing Plants
Woody plant
boreal
Native flora
Wolf Willow
Elaeagnus commutata.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PBA006
Abstract ID:775
Candidate for Awards:Ian and Syvia Taylor Award