Effects of simulated waterlogging on growth, physiological and biochemical characteristics of Metasequoia glyptostroboides seedlings
The disruption of natural flow regimes in river systems poses many challenges to riparian ecosystems and their native species. The construction of the Three Gorges Dam has altered the flow regimes of the upper Yangtze River and created a riparian zone with a vertical gap of 30 m. Because of the anti...
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| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Zhejiang University Press
2015-09-01
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| Series: | 浙江大学学报. 农业与生命科学版 |
| Subjects: | |
| Online Access: | https://www.academax.com/doi/10.3785/j.issn.1008-9209.2014.09.292 |
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| Summary: | The disruption of natural flow regimes in river systems poses many challenges to riparian ecosystems and their native species. The construction of the Three Gorges Dam has altered the flow regimes of the upper Yangtze River and created a riparian zone with a vertical gap of 30 m. Because of the anti-seasonal change of the water level caused by annual water regulation, plants grown on the riparian zone of the Three Gorges Reservoir Area (TGRA) may suffer from submergence, and often display dynamic change characteristics. Such water level change is likely to disturb the normal ecophysiological rhythm of the native tree species of the riparian zone. These hydrological changes highlight the importance of screening suitable tree species for reforestation in the TGRA and similar environments. Thus, the native tree species Metasequoia glyptostroboides, will most likely to experience continuous submergence or inundation. Current research on M. glyptostroboides seedlings is more focused on genetic structure, membrane composition, chemical property, growth and photosynthesis, and the like. However, the eco-physiological implications of submersion on M. glyptostroboides seedlings are not well known, especially under the condition of full-submersion.The aim of this study was to investigate the responding characteristics of the M. glyptostroboides seedlings to the water level change in the TGRA, and provide theoretical basis for species selection for revegetation in the riparian zone of the TGRA.Measured indexes included protective enzymes such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (ASP) and catalase (CAT), osmotic adjustment substances such as soluble protein and free proline, and membrane lipid peroxidation such as malondialdehyde (MDA), as well as photosynthetic characteristics and biomass accumulation of the two-year old M. glyptostroboides seedlings to submergence, upon mimicking the water level change in the riparian zone of the TGRA. Based on soil moisture change pattern in the TGRA, water treatments including control (CK), half-submersion (HS), and full-submersion (FS) were applied.The activities of SOD, POD, ASP, CAT and content of free proline of M. glyptostroboides seedlings in HS and FS group were higher than that in CK after submersion. Under submersion, MDA content in HS and FS group increased as compared with that in CK. The net photosynthetic rate of M. glyptostroboides seedlings in HS was significantly higher than that in CK. Root-shoot ratio in FS was significantly higher than that in CK, but no significant difference was detected between FS and HS. Leaves of M. glyptostroboides seedlings in FS were leaf bud, and survival rates were 100%.The results indicated that antioxidant enzymes, osmotic adjustment substances and photosystem Ⅱ have a positive response during submersion, M. glyptostroboides seedlings show strong adaptability to the submersion. Thus, M. glyptostroboides should be considered as one of the potential species for revegetation in the TGRA. |
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| ISSN: | 1008-9209 2097-5155 |