Abstract:

The waterlogging tolerance of Taxodium mucronatum Tenore seedlings was evaluated by artificially simulating different degrees of waterlogging stress environment. The two years old seedlings of Taxodium mucronatum Tenore were treated under different waterlogging stresses, including total submersion of the seedlings (full flooding), submersion from the middle part of the seedlings (half-flooding), submersion of the root (shallow flooding), and no submersion of the seedlings (control). Then the change rules of the content of soluble protein, proline, soluble sugar and malondialdehyde (MDA), and the activity of peroxidase in seedling leaves were measured and analyzed. The results showed that during the entire test period, the effects of different waterlogging stresses on the physiological and biochemical indexes of Taxodium mucronatum reached an extremely significant difference (P<0.01). With the aggravation of the waterlogging degree, the changes of physiological and biochemical indexes in seedling leaves under different treatments were also quite different: on the one hand, the content of malondialdehyde (MDA) and the activity of peroxidase increased, on the other hand, with the extension of the waterlogging time, the soluble protein content, proline content and soluble sugar content showed complex changes in a repeated first-increase-then-decrease way. In summary, Taxodium mucronatum seedlings have a strong ability to withstand the waterlogging stress, and can survive in shallow flooding and half-flooding environment for a long time, even the seedlings in full flooding environment will not die in a short time.

Key words: Taxodium mucronatum Tenore, waterlogging stress, physiological and biochemical characteristics