摘要
以盆栽杠柳幼苗为材料,用称重控水的方法设置4个含水量梯度,研究不同程度干旱胁迫对杠柳光合特性和抗氧化系统的影响,为黄河三角洲贝壳堤岛植被恢复过程中的物种培育和种植管理提供依据。结果表明:(1)随着干旱胁迫的加剧,杠柳幼苗叶片净光合速率(Pn)先增后降,蒸腾速率(Tr)和气孔导度(Gs)逐渐下降,胞间CO2浓度(Ci)先降后升,说明杠柳幼苗Pn下降在轻度干旱胁迫下主要是由气孔导度下降引起,而在重度胁迫下主要由非气孔因素引起。(2)随着干旱胁迫程度的加剧,杠柳幼苗瞬时水分利用效率(WUE)、表观光能利用效率(LUE)、羧化效率(CE)均呈现先增加后下降趋势;WUE在重度胁迫下才开始下降,比对照显著下降了39%,LUE(CE)则在中度胁迫下就开始下降,中度和重度胁迫分别比对照下降了48%(33%)、71%(69%)。(3)随着干旱胁迫的加剧,杠柳叶片的超氧化物歧化酶(SOD)活性先升高后降低,过氧化物酶(POD)、过氧化氢酶(CAT)活性和MDA含量均逐渐增高,表明POD、CAT抑制杠柳叶片脂质过氧化效应不显著,SOD则抑制作用显著,且12.8%的贝壳沙含水量是SOD的耐受阈值,此时MDA含量比对照显著增加153%。
In order to provide countermeasures for species cultivation and planting about vegetation recovery of shell islands in Yellow River Delta.With Periploca sepium seedlings as materials,the effects of different drought stress on gas exchange and systems of anti-oxidation were conducted.Four treatments were arranged：control,light drought,moderate drought and heavy drought.Results showed：（1）With the drought stress increasing,net photosynthesis rate first increased and then decreased,transpiration rate and stomatal conductance decreased,intercellular CO2 concentration first decreased and then increased.Under light stress,the decline of netphotosynthetic rate of P.sepium seedlings was caused by stomatal conductance decreasing.However,it is mainly by non-stomatal factors under heavy stress.（2）With the drought stress increasing,instantaneous water use efficiency,apparent light use efficiency and carboxylation efficiency of P.sepium seedlings showed the tendency of increase-decrease.Instantaneous water use efficiency decreased by 39% under heavy stress,apparent light use efficiency（apparent CO2 use efficiency）decreased by 48%（33%）,71%（69%） under moderate stress and heavy stress.（3）With the drought stress increasing,the activity of superoxide dismutase（SOD） of P.sepium first increased and then decreased,peroxidase（POD）,catalase（CAT）,the content of malondialdehyde（MDA） always increased.The effect of POD,CAT to prevent lipid peroxidation is not significant,SOD is significant.The content of shell sand moisture at 12.8% was the limit of the activity of SOD,the content of malondialdehyde（MDA） of P.sepium in the leaves increased by 153%.
出处
《西北植物学报》
CAS
CSCD
北大核心
2010年第12期2466-2471,共6页
Acta Botanica Boreali-Occidentalia Sinica
基金
山东省自然科学基金(Y2006D01
Y2008D52)
山东省高等学校科技计划项目(J09LC64)
山东省黄河三角洲生态环境重点实验室开放基金(2008KFJJ02)
滨州学院科研基金项目(BZXYL1008)
关键词
杠柳
气体交换
保护酶
干旱胁迫
Periploca sepium Bunge
gas exchange
protective enzyme
drought stress
