重复淹水对三峡库区消落带菖蒲植被生长发育的影响

Influence of the Repeated Flooding on Growth and Development of Acorus calamus Vegetation in Water-level-fluctuation Zone of the Three Gorges Reservoir

[目的]研究重复淹水对三峡库区消落带菖蒲植被生长发育的影响。[方法]分别于2009年9月和2010年9月在无光条件下将菖蒲植株完全淹水,并分别于翌年3、4月将植株露水(分别记为S1、S2、S’1、S’2),统计植株数,并于5月7日统计各组植株的叶片数,测定叶长、叶宽及叶片的快速光响应曲线。[结果]无光、重复淹水显著抑制了植株的萌发,与对照相较,S’1和S’2组萌发形成的植株数分别降低了38.9%、33.3%,差异显著;并显著降低了植株的存活率,与第1次淹水相较,S’2组植株露水时,植株数降低了16.7%(P<0.05)。2次淹水均促进了植株叶片的伸长,抑制了植株叶宽的增加,除S1和S’1组外,2次淹水均显著抑制了植株叶片的形成。再次淹水后,植株的株叶长显著降低,S’1和S’2组的株叶长分别比上年低50.6%、36.9%,差异显著;总叶片数显著减少,S’1和S’2组总叶片数分别仅为对照的63.1%、38.5%,差异显著;与第1次淹水相较,对照总叶长显著增加,而S’2组总叶长显著降低。S’1组相对电子传递速率(rETR)的光响应能力与对照差异不显著,S’2组rETRmax显著低于对照,且S’1和S’2组热耗散系数(NPQ)显著降低,表明菖蒲植株具有较强的光响应恢复能力,但是热耗散能力恢复较慢。[结论]在无光条件下,重复淹水会抑制菖蒲植株的生长及种群恢复。

[ Objective ] The research aimed to study influence of the repeated flooding on growth and development of A. calamus in water-lev- el-fluctuation zone of the Three Gorges Reservoir. [ Method^A. calamus plants were exposed to water under the dark conditions respectively in September 2009 and September 2010. Then, they were taken away from the water, and grew in natural conditions in the following March and A- pril respectively （marked as S1 ,S2,S＇ 1 aud S＇ 2）. The plant number was conducted statistics respectively. On May 7, the leaf number was made statistics. Length,width and rapid light responding curves of the leaves were determined. [Result] Repeated flooding restrained signifi- cantly plant germination under the dark condition. Plant number in S＇ 1 and S＇2 groups decreased by 38.9% and 33.3% respectively com- pared with the control. It also reduced survival rate of the plant. Plant number in S＇2 group decreased by 16.7% （P 〈 0.05 ） compared with that of $2 group when they were taken away from the water. Both of flooding promoted elongation of the leaves, restrained leaves to grow wider, and also restrained leaf formation of the plants except for S1 and S＇ 1 groups. Total leaf length of a plant decreased markedly after the second flooding which in S＇ 1 and S＇ 2 groups were 50.6% and 36.9% respectively less than that after the first flooding. Total leaf number of the plant in S＇ I and S＇2 groups reduced significantly, and they were only 63.1% and 38.5% respectively of the control. Compared with the first flood- ing,total leaf length of a plant in the control increased significantly and decreased remarkably in S＇2 group after the second flooding. Further- more,light response ability of the relative electronic transfer rate （rETR） in S＇ 1 group wash＇ t significantly different from the control, and rETRmax in S＇2 group was significantly less than the control. Moreover, non-photochemical quenching （NPQ） decreased remarkably in S＇ 1 and S＇ 2 groups. It indicated that A. calamus had good restore ability of the light response, but restoring of its heat dissipation capacity was slower. [ Conclusion] Repeated flooding inhibited plant growth and population recovery of A. calamus under the dark condition.