摘要
为探讨CO_2浓度倍增和干旱胁迫对紫花苜蓿(Medicago sativa)生理作用的协同效应,采用人工气候室和控水试验模拟CO_2浓度倍增和干旱胁迫,分析了植物光合和抗逆生理特征的变化规律。结果表明:干旱胁迫与CO_2浓度倍增对苜蓿光响应参数影响显著,二者之间具有一定的交互作用,在干旱胁迫下,CO_2浓度倍增减缓了苜蓿叶片气孔导度(G_s)、蒸滕速率(T_r)和光饱和点(LSP)的降低幅度,而对最大净光合速率(P_(max))、胞间CO_2浓度(C_i)和表观量子效率(AQE)没有减缓作用。CO_2浓度倍增下的水分利用效率(WUE)高于正常CO_2浓度,而与水分含量关系不大。干旱胁迫与CO_2浓度倍增对苜蓿光合色素、丙二醛(MDA)和脯氨酸(Pro)含量影响显著,干旱胁迫在一定程度上降低了叶绿素a(chl a)、叶绿素b(chl b)的含量和叶绿素总量,显著增加了叶片MDA和Pro含量,CO_2浓度倍增有增加这些光合色素含量、降低MDA和Pro的趋势;但2个因素之间没有显著交互作用。干旱胁迫和CO_2浓度倍增对苜蓿叶绿素荧光参数影响不一,干旱胁迫和CO_2浓度倍增对叶绿素荧光参数具有较强的交互作用,CO_2浓度倍增对植物体光合电子传递过程中的保护作用在植物受到干旱胁迫时更加明显。因此,在干旱、半干旱地区,干旱胁迫对苜蓿光合生理功能产生不利的影响,而CO_2浓度倍增对苜蓿的生长具有一定的施肥效应,当2个因素共同发生时,CO_2浓度倍增可以减缓水分胁迫对苜蓿的伤害,增强其抗旱能力,提高水分利用效率,缓解干旱胁迫的负面效应。
In order to study the photo-physiological characteristics of Medicago sativa in the loess hilly-gul ly region under different water stress and CO2 concentration, the photosynthetic and physiological charac teristics of plant were analyzed with different scenarios using artificial climate chamber and water control simulation. Results showed that the photo-physiological characteristics of alfalfa were significantly affected by drought stress and doubled CO2 concentration, and there were synergistic effects between them. Under drought stress, the doubled CO2 concentration improved G,, Tr and LSP, but had no effect on P Ci and AQE, as compared with those under ambient CO2 concentration. The water use efficiency （WUE） under double COz concentration was higher than under normal CO2 concentration, but had no significant correla tion with moisture content. Drought stress and doubled CO2 concentration had significantly effects on pho tosynthetic pigment, malondialdehyde （MDA） and proline （Pro）. Drought stress, to a certain extent, de creased the chlorophyll a （chl a）, chlorophyll b （chl b） and the total chlorophyll contents, while increasedsignificantly the MDA and Pro contents of plant. Doubled CO2 concentration decreased the photosynmetm pigment contents of plant, and improved the MDA and Pro contents of plant. However, there were no sig nificant synergistic effects between them. Drought stress and double CO2 concentration had different effects on the fluorescence parameters of chlorophyll, and there was a strong synergistic effect between them. Under drought stress, doubled CO2 concentration had more obvious protection on the photosynthet ic electron transport in the plants. Therefore, the above results indicated that in arid and semi-arid area, doubled CO2 concentration had definite compensation effects on the photosynthetic physiological functions of alfalfa induced by drought stress, and enhanced drought resistance capacity, improved water use effi- ciency and alleviated the negative effects of d
出处
《草地学报》
CAS
CSCD
北大核心
2014年第1期85-93,共9页
Acta Agrestia Sinica
基金
西北农林科技大学基本科研业务费专项(ZD2013021)
中国科学院战略性先导科技专项(XDA05060300)
陕西省科学技术研究发展计划项目(2011KJXX63)资助
关键词
紫花苜蓿
光合生理特性
CO2浓度倍增
干旱胁迫
协同效应
Medicago sativa
Photo-physiological characteristics
Doubled CO2 concentration
Droughtstress
Synergic effect
