干旱胁迫对4个油茶品种光合特性的影响

Effects of drought stress on photosynthetic characteristics of four Camellia oleifera clones

为了科学判断不同油茶品种的抗旱性差异,从而为油茶产业在干旱区域的推广提供参考,以桂无1号、桂无4号、岑软2号和岑软3号共4个油茶品种为材料,分别设置PEG 6000(10%,20%,30%)模拟干旱胁迫,给予持续12、24、36 h干旱胁迫以及营养液恢复12 h处理,测定各处理的光合生理指标。结果表明,干旱胁迫下,4个油茶品种的净光合速率(Pn)、蒸腾速率(Tr)以及气孔导度(Gs)均显著下降;除岑软2号中度和重度胁迫处理中胞间CO2浓度(Ci)持续增加外,其余处理Ci呈现"先降低后升高"的变化趋势;水分利用效率(WUE)的变化较为波动,岑软2号和岑软3号整体处于较高水平。复水后,岑软3号多个光合生理指标有恢复迹象。隶属函数分析结果表明,4个油茶品种的抗旱能力由强到弱依次为岑软3号、岑软2号、桂无4号、桂无1号。

In order to clarify drought resistance differences of different Camellia oleifera varieties,and to provide somereferences for C.oleifera industry promotion at drought regions,using four C.oleifera clones of Guiwu No.1,GuiwuNo.4,Cenruan No.2and Cenruan No.3as materials,photosynthetic physiological indices were determined under differenttreatment conditions.Drought stress conditions were similated by using PEG6000(10%,20%,30%)and last for differenttime(12,24,36hours),and then the materials were treated for12hours in nutrient solution.The results showed thatduring drought stress periods,net photosynthetic rate(Pn),transpiration rate(Tr)and stomatal conductances(Gs)of thefour clones were significantly decreased;intercellular CO2concentrations(Ci)of Cenruan No.2went up gradually inmoderate and severe stress treatments,but in contrast those went down firstly and then went up in the other treatments;changes of water use efficiencies(WUE)were at fluctuating states,those of Cenruan No.2and Cenruan No.3maintainedat higher levels.Most of the photosynthetic physiological indices of Cenruan No.3generally recovered after treated in thenormal nutrient solution.The results of subordinate function analysis showed that the order of the four C.oleifera cloneswas Cenruan No.3,Cenruan No.2,Guiwu No.4,Guiwu No.1based on drought resistance from strong to weak.