作 者：
朱启红;李鹏辉;李爽;韩丽霞;夏红霞;李强
单 位：
重庆文理学院水环境修复重点实验室;重庆市环境材料与修复技术重点实验室
摘 要：
以海芋(Alocasia macrorrhiza)为材料进行干旱胁迫和淹水胁迫各7 d的试验,研究短期干湿交替胁迫对其光合特性的影响。淹水胁迫试验设置A为对照(淹没根部)、B为轻度胁迫(1/4淹水)、C为中度胁迫(1/2淹水)、D为重度胁迫(3/4淹水)、E为深度胁迫(全淹)。结果表明,短期弱干旱胁迫时,植株叶片光合有效辐射(PAR)、气孔导度(Gs)、净光合速率(Pn)、胞间CO2浓度(Ci)、蒸腾速率(Tr)等光合参数变化不大,趋于同一水平;但淹水胁迫对植株光合作用影响很大,不同淹水梯度的植株间差异显著;短期适宜淹水梯度(淹没根部、1/4淹水、1/2淹水)促进了植株光合作用,尤其是处理B(1/4淹水)在2次复水时其PAR、Gs、Pn、Tr均显著上升(P<0.05);而高水位胁迫(3/4淹水和全淹)则抑制植株光合作用。利用海芋构建人工湿地系统时,可以通过人为措施使海芋处于适宜水位以利其生长,从而提高对废水的净化效果。
译 名：
Effect of Alternating Wet and Dry Conditions on the Photosynthetic Characteristics of Alocasia macrorrhiza
作 者：
ZHU Qi-hong;LI Peng-hui;LI Shuang;HAN Li-xia;XIA Hong-xia;LI Qiang;Chongqing Key Laboratory of Environmental Materials & Remediation Technologies;Key Laboratory of Water Environment Restoration,Chongqing University of Arts and Sciences;
关键词：
Alocasia macrorrhiza;;photosynthesis;;alternating wet and dry conditions;;stress
摘 要：
The physiological response of wetland plants to different degrees of water availability reflects their adaptability and influences the ability of a wetland system to purify water.This study of the photosynthetic response to alternating wet and dry conditions provides information that will support the construction and restoration of wetland systems.Research has shown that Alocasia macrorrhiza contributes to water purification,an important benefit provided by wetlands.The effects of short term variation between wet and dry conditions on the photosynthetic characteristics of Alocasia macrorrhiza were investigated and the results provide a theoretical basis for constructed wetlands designed to operate effectively during both wet and dry seasons.Five treatments were used to study the effect of various degrees of plant submersion:A(control,root submerged),B(1 /4 submerged),C(1 /2 submerged),D(3 /4 submerged) and E(fully submerged).One pot,containing a pair of Alocasia macrorrhiza plants(50 ±3) cm was subjected to each treatment in a water tank(2.0 m × 0.5 m × 0.7 m).Dry-wet alternation was carried out twice and conditions were altered after a period of seven days.After each seven-day period,one plant from each pot was selected randomly and photosynthetic parameters were measured using a LI-6400 XT portable photosynthesis analyzer.Results show that under low(short term) drought stress,the photosynthetic parameters [photosynthetic active radiation(PAR),stomatal conductance(Gs),net photosynthetic rate(Pn),intercellular CO2concentration(Ci) and transpiration rate(Tr) ]displayed little change.However,submergence stress did affect photosynthesis and the differences among submergence levels were significant.Results also revealed that short term submergence(root,1 /4 and 1 /2 submerged) enhanced photosynthesis.In particular,PAR,Gs,Pnand Trof Group B(1 /4submerged) increased significantly(P < 0.05) after both the first and the second rehydration.However,3 /4 and full submergence suppressed photosynthesis in Alocasia macrorrhiza.In conclusion,alternating wet and dry conditions with different degrees of submergence had significant effects on photosynthetic parameters.At low water levels(Groups A,B,C),PAR,Gs,Pnand Trincreased and Cidecreased.In contrast,PAR,Gs,Pnand Trdecreased at higher water levels(Groups D,E) while Ciincreased.Alocasia macrorrhiza is sensitive to water level and,to achieve effective wastewater purification in constructed wetlands,the species should be cultivated at suitable water levels.
