水分胁迫对闽楠幼苗生理及光合特性的影响  

Effects of water stress on the physiological and photosynthetic characteristics of Phoebe bournei seedlings

作　　者：苏春莉 段姚 顾振瀛 郑鹏丽 黄晓蓉[1,2] 费永俊[1,2] 周明芹[1,2] SU Chunli;DUAN Yao;GU Zhenying;ZHENG Pengli;HUANG Xiaorong;FEI Yongjun;ZHOU Mingqin(College of Horticulture and Gardening,Yangtze University,Jingzhou 434025,Hubei,China;Center of Phoebe Germplasm Resources Evaluation and Innovation,Yangtze University,Jingzhou 434025,Hubei,China)

机构地区：[1]长江大学园艺园林学院,湖北荆州434025 [2]长江大学楠木种质资源评价与创新中心,湖北荆州434025

出　　处：《中南林业科技大学学报》2022年第6期85-92,共8页Journal of Central South University of Forestry & Technology

基　　金：国家自然科学基金项目(31200528)。

摘　　要：【目的】探讨水分胁迫下闽楠幼苗在光合生理方面的响应机制,以期为闽楠苗木培育与园林应用中的水分管理提供理论依据。【方法】以双套盆法栽培的2年生闽楠幼苗为材料,设重度水淹(P1)、轻度水淹(P2)、对照(CK,维持盆土的相对含水量为最大持水量的75%~80%)和干旱(不浇水,P3)4个处理,观测幼苗的生长状态,测定过氧化物酶(POD)与超氧化物歧化酶(SOD)的活性、丙二醛(MDA)、脯氨酸(Pro)和可溶性蛋白(SP)的含量等生理指标以及净光合速率(P_(n))、胞间CO_(2)浓度(C_(i))、气孔导度(G_(s))和蒸腾速率(T_(r))等光合参数的变化。【结果】水分胁迫下,闽南幼苗叶片呈现萎蔫、下垂的症状;植株生长缓慢,甚至死亡,以重度水淹最为严重,胁迫解除5 d后的存活率为87.7%(其余的存活率为100%);水分胁迫下,MDA含量明显增多,胁迫解除后,MDA含量呈下降趋势;重度水淹、轻度水淹和干旱胁迫的前15 d,POD和SOD的活性显著升高,前者增幅最大并维持在较高水平,干旱胁迫次之,而轻度水淹SOD活性呈先上升后下降再上升的变化趋势,POD在15 d后逐步下降;Pro和SP的含量基本呈先上升后下降的变化趋势;P_(n)、G_(s)和T_(r)呈现出先下降再上升后下降的变化趋势,重度水淹变化幅度最大,C_(i)呈先上升后下降的变化趋势。【结论】闽楠幼苗具有一定的抗旱和抗涝能力,但长期水涝不利于其生长;水淹和干旱胁迫均会导致闽楠幼苗的光合作用和蒸腾作用降低,且水淹程度越深,抑制越明显。叶片SP合成速率高于胁迫过程中的分解速率,表明闽楠具有一定的抗逆性。【Objective】In order to provide a theoretical basis for the water management in Phoebe bournei seedling cultivation and its ecological utilization in landscape architecture,we explored the photosynthetic and physiological response of Phoebe bournei under water stress.【Method】Using the two-year-old seedlings cultivated by the double-pot method,four treatments were set up:severe flooding(P1),mild flooding(P2),control(CK,the relative water content of basin soil was maintained at 75%-80%of the maximum water holding capacity)and drought(no watering and natural drought,P3).The growth status of seedlings was observed,the activities of peroxidase(POD)and superoxide dismutase(SOD),the contents of malondialdehyde(MDA),proline(pro)and soluble protein(SP)and the changes of net photosynthetic rate(P_(n)),intercellular CO_(2) concentration(C_(i)),stomatal conductance(G_(s))and transpiration rate(T_(r))of seedlings were determined.【Result】Under water stress,leaves showed the symptoms of wilting and drooping,the plants grew slowly or died,and severe flooding was the most serious,under which conditions the plants survival rate was 87.7%after five days of stress relief(the survival rate of other conditions was 100%).The MDA content increased significantly during water stress and decreased after the stress relief.After 15 days treatment of severe flooding,mild flooding and drought stress,the activities of POD and SOD increased significantly,which exhibited the highest increase under severe flooding treatment,followed by drought stress.However,under mild flooding,the SOD activity showed a trend of increasing first,then decreasing,and increasing at last,while the POD activity gradually decreased.The contents of Pro and SP were increased firstly and then decreased.The values of P_(n),G_(s) and T_(r) showed a trend of first decreasing,then increasing and then decreasing,with the largest change in severe flooding,while C_(i) showed a trend of first increasing and then decreasing.【Conclusion】Phoebe bournei seedlings have a

关 键 词：闽楠 水分胁迫 光合生理 生长特性 生理生态指标 

分 类 号：S792.24[农业科学—林木遗传育种]