干旱胁迫及复水对香樟幼树生理特性及生长的影响  

Physiological Properties and Growth of Cinnamomum camphora Saplings under Drought Stress and Rewatering

作　　者：胡义[1] 胡庭兴[1] 陈洪[1] 王彬[1] 李晗[2] 

机构地区：[1]四川农业大学林学院,四川雅安625014 [2]四川农业大学生态林业研究所,成都611130

出　　处：《西北植物学报》2015年第2期294-301,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金："十二五"国家科技支撑计划项目(2011BAC09B05);"十二五"四川省农作物育种攻关项目(2011NZ0098-10)

摘　　要：通过盆栽和持续干旱处理研究了轻度干旱（持续干旱2～4 d）、中度干旱（持续干旱6～8 d）和重度干旱胁迫（持续干旱10～16 d）及复水对香樟（Cinnamomum camphora）幼树生理特性和生长的影响,为香樟育苗、造林及合理的水分管理提供理论依据。结果显示：（1）干旱胁迫下香樟幼树地径生长量（Zd）和树高生长量（Zh）受到了抑制;轻度、中度干旱处理（土壤体积含水量从正常状态下降到7%）下叶片相对含水量（LRWC）与对照差异不显著,重度干旱处理（土壤体积含水量下降到3%）下显著低于对照。（2）轻度、中度干旱处理的超氧阴离子和过氧化氢含量与对照无显著差异,重度干旱处理较对照显著上升。（3）在活性氧酶促清除系统中,超氧化物歧化酶（SOD）、过氧化物酶（POD）活性在轻度干旱时显著上升,而过氧化氢酶（CAT）活性在重度干旱时才显著上升,在复水48 h后3种酶活性均恢复到对照水平。（4）在轻度、中度干旱处理中叶片丙二醛（MDA） 含量无显著变化,而在重度干旱下显著升高,且复水48 h后未见显著降低。（5）在渗透调节物质中,轻度干旱时可溶性蛋白（SP）含量开始显著升高,中度干旱时可溶性糖（SS）含量显著升高,重度干旱时脯氨酸（Pro）含量显著上升;复水48 h后Pro含量显著降低,而可溶性蛋白和可溶性糖含量无显著变化。研究发现,香樟幼树在轻度干旱胁迫下能通过自身抗氧化酶系统和渗透调节物质维持正常生长,而在中度和重度干旱胁迫条件下,其水分生理状况变差,膜系统遭受伤害,酶活性受到抑制,最终导致其形态生长和地上部分生物量积累受限。A pot experiment was conducted to investigate the effects of continuously drought stress（stopped watering for 0 d,2 d,4 d,…16 d,respectively） and rewatering on the growth and physiological properties of Cinnamomum camphora.The results showed that：（1）The diameter increment（Zd） and the height increment（Zh） were both inhibited under drought stress,Leaf relative water content（LRWC） under mild and moderate drought（stopped watering for 2-8 d and soil volumetric water content（SWC） decreased to 7%） were not significantly lower than that in control（D0）,but significantly lower than those under severe drought（stopped watering for more than 10 d and soil volumetric water content decreased to 3%）.（2）The concentration of O-·2 and H2O2 significantly increased under severe drought stress.（3）The activities of superoxide dismutase（SOD） and peroxidase（POD） were promoted significantly during mild and moderate drought stress while catalase（CAT） activity increased significantly in severe drought stress,After rewatering for 48 h,the activities of these three enzymes decreased.（4）The contents of malondialdehyde（MDA） and proline（Pro） increased significantly under severe drought.（5）The contents of soluble protein（SP） increased dramatically under mild drought,while that of soluble sugar（SS） raised significantly under moderate drought.Both of them then did not decreased,after rewatering for 48 h.The study suggests that C.camphora saplings under mild drought maintained normal growth through ROS scavenging system and osmotic adjustment,while suffered from moderate and severe drought stress,the water physiology became deteriorated,membrane system was injured,enzyme activities affected,and at last the morphological growth and aboveground biomass were depressed by the drought stress.

关 键 词：香樟幼树 干旱胁迫 复水 生理特性 生长 

分 类 号：Q945.78[生物学—植物学]