EFFECTS OF SUBMERGENCE ON MORPHO-PHYSIOLOGICAL CHARACTERISTICS AND RECOVERY OF BERMUDAGRASS (Cynodon dactylon)

Plant survival and recovery after submergence are greatly affected by duration and water depth, and they are particularly important for species establishment in periodic submergence habitat. In this study, we conducted a research on the morphological changes, aerenchyma formation, biomass allocation and its recovery of bermudagrass after submergence. All deep-submerged plants survived and regenerated quickly after they were de-submerged in the present research. The photosynthetic abilities of the submerged plants had recovered well after re-emergence for 30 d. The biomass decreases were progressive and proportional to the stress magnitude (i.e., depth and duration), and at the end of the experiment, total biomasses of 1, 5 and 15 m depth submerged plants were 61%, 53% and 39% of their initial total biomass, respectively. Aerenchyma contents in shoots and roots increased with the increase of submergence depth. We concluded that bermudagrass had submergence-tolerance instinct, and the main reasons of bermudagrass enduring long-term and deep submergence were followings: (1) photosynthesis recovery after reaeration; (2) aerenchyma development; (3) keeping higher biomass remainder.