水生态学杂志Issue(6)：88-92,5.
干湿交替对海芋光合特性的影响
Effect of Alternating Wet and Dry Conditions on the Photosynthetic Characteristics of Alocasia macrorrhiza
摘要
Abstract
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 ± 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 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) 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 condi-tions with different degrees of submergence had significant effects on photosynthetic parameters.At low water levels (Groups A, B, C), PAR, Gs, Pn and Tr increased and Ci decreased.In contrast, PAR, Gs, Pn and Tr decreased at higher water levels ( Groups D, E) while Ci increased.Alocasia macrorrhiza is sensitive to water level and, to a-chieve effective wastewater purification in constructed wetlands, the species should be cultivated at suitable water levels.关键词
海芋/光合作用/干湿交替/胁迫Key words
Alocasia macrorrhiza/photosynthesis/alternating wet and dry conditions/stress分类
生物科学引用本文复制引用
朱启红,李鹏辉,李爽,韩丽霞,夏红霞,李强..干湿交替对海芋光合特性的影响[J].水生态学杂志,2014,(6):88-92,5.基金项目
重庆市教委资助项目（ KJ131207）；重庆市自然科学基金计划项目（cstc2013jcyjA20024）。 （）
