• 研究简报 •

### 水淹对水杉苗木耐旱性的影响

1. 西南大学生命科学学院 三峡库区生态环境教育部重点实验室 重庆 400715
• 收稿日期:2014-01-20 修回日期:2014-04-21 出版日期:2014-11-25 发布日期:2014-12-04
• 通讯作者: 李昌晓
• 基金资助:

重庆市基础与前沿研究计划重点项目(CSTC2013JJB00004);国家林业公益性行业科研专项(201004039);留学回国人员科研启动基金(教外司留);中央高校基本科研业务费专项资金(XDJK2013A011).

### Effects of Submersion on Susceptibility of Metasequoia glyptostroboides Seedlings to Drought

Bai Linli, Li Changxiao

1. Key Laboratory for the Eco-Environment of the Three Gorges Reservoir Region of Ministry of Education College of Life Sciences, Southwest University Chongqing 400715
• Received:2014-01-20 Revised:2014-04-21 Online:2014-11-25 Published:2014-12-04

Abstract:

Photosynthetic and growth responses of two-year-old Metasequoia glyptostroboides seedlings to drought following flooding were explored upon simulating water level change in the hydro-fluctuation belt of the Three Gorges Reservoir Area (TGRA). The seedlings were subjected to treatments of six water regimes, including control (C), control followed by drought (CD), continuous half-submersion (HS), half-submersion followed by drought (HSD), continuous full-submersion (FS) and full-submersion followed by drought (FSD). Results showed that net photosynthetic rate (Pn) of M. glyptostroboides seedlings in the HS group (submersion for 60-day) was significantly higher than that in C group. Conversely, a submersion for 120 d, the Pn in HS, and root and total biomass were significantly lower than that in C. However, under drought treatment, the Pn and stomatal conductance (Sc) in CD and HSD were significantly decreased as compared to that in C, while there were no significant differences in Pn and Sc between FSD and C. Similarly, the root and total biomass significantly declined in all of the three drought conditions compared to C. By the end of the recovery period, Pn and Sc of the seedlings under different water stresses were increased to a comparable level as that of C, respectively, except for the Pn in HSD and FS. These results indicated previous flooding had no detectable effect on subsequent sensitivity of M. glyptostroboides seedlings to drought. The M. glyptostroboides showed certain adaptation to the flooding and drought, and thus can be considered as a candidate for the restoration in the hydro-fluctuation belt of the TGRA.