Physiological Effects of Salt Spray Stress on Seedlings of Araucaria cunninghamii

From August to September 2021, the annual seedlings of Araucaria cunninghamii were used as experimental materials in Xiamen Garden Botanical Garden to study the changes of physiological indicators of Araucaria cunninghamii seedlings under different concentrations of salt spray stress.The results showed that with the increase of the mass fraction of salt spray, the total chlorophyll content in seedlings of Araucaria cunninghamii decreased, the proline content increased first and then decreased, the relative conductivity increased, and the activities of superoxide dismutase (SOD) and peroxidase (POD) increased first and then decreased.From the perspective of growth performance, when the salt spray mass fraction is ≤ 2.8%, the seedlings of Araucaria cunninghamii show slight leaf yellowing, but their growth is normal.When the salt spray mass fraction is 3.5%, the seedlings of Araucaria cunninghamii begin to show a large amount of leaf tip yellowing, wilting, and plant tip withering.Based on the comprehensive experimental results, the Araucaria cunninghamii spruce has a certain salt tolerance ability.The one-year old seedlings are treated with salt spray twice a day for 30 days, the results showed that the highest salt spray mass fraction that can be tolerated by the seedlings of Araucaria cunninghamii was 2.8%.