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。
The physiological response of wetland plants to different degrees of water availability reflects their adapt-ability and influences the ability of a wetland system to purify water.This study of the photosynthetic response to al-ternating 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 pro-vided by wetlands.The effects of short term variation between wet and dry conditions on the photosynthetic charac-teristics 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 va-rious 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 ＆#177; 3） cm was subjected to each treatment in a water tank （2.0 m ＆#215;0.5 m ＆#215;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 CO2 concentration （ 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, Pn and Tr of Group B （1/4 submerged） increased significantly （P〈0.05） af
出处
《水生态学杂志》
北大核心
2014年第6期88-92,共5页
Journal of Hydroecology
基金
重庆市教委资助项目(KJ131207)
重庆市自然科学基金计划项目(cstc2013jcyj A20024)
关键词
海芋
光合作用
干湿交替
胁迫
Alocasia macrorrhiza
photosynthesis
alternating wet and dry conditions
stress
