Different Phenotypic, Photosynthetic, and Physiological Responses to Flooding between and .

Flooding stress is an increasingly serious problem in wetlands, often affecting large areas of crops and timber production areas. The current study aimed to explore the species differences in responses to flooding stress between and in an outdoor environment. All the tested plants survived after a 60-day flooding treatment that left 5 cm of water above the soil surface. This suggests that the two species are flood-tolerant, so they can be applied in the construction of riparian protection forests and wetland restoration. Compared with control conditions, flooding treatment significantly decreased seedling height and diameter and the P, G, T, F/F, ABS/CS, TR/CS, ET/CS, RE/CS, IAA, and GA content and significantly increased the content of MDA, HO, soluble sugars, SOD, POD, ADH, ABA, and JA. Under control conditions, showed significantly greater growth and photosynthetic capability than . In contrast, exhibited less inhibition of growth and photosynthesis, oxidative stress levels, and antioxidant enzyme activities than under flooding conditions. The findings indicate that has better defense mechanisms against the damage caused by flooding stress than . was more sensitive and responsive to flooding than .