水分胁迫对桢楠幼树光合生理特性的影响  

Effects of water stress on photosynthetic physiology characteristics of Phoebe zhennan seedlings

作　　者：郑鹏丽 黄晓蓉[1] 费永俊[1] 周明芹[1] ZHENG Pengli;HUANG Xiaorong;FEI Yongjun;ZHOU Mingqin(Center of Phoebe Germplasm Resources Evaluation and Innovation,Yangtze University,Jingzhou 434025,Hubei,China)

机构地区：[1]长江大学楠木种质资源评价与创新中心

出　　处：《中南林业科技大学学报》2019年第10期64-70,共7页Journal of Central South University of Forestry & Technology

基　　金：国家自然科学基金资助项目(31200528)

摘　　要：以2年生桢楠幼树为材料,采用双套盆法对其进行不同程度的水分胁迫处理(水涝、水渍、自然条件和干旱),研究了水分胁迫对桢楠幼树光合生理指标的影响,以期为桢楠幼树的培育及其人工林科学的水分管理提供理论依据。结果表明:1)水分胁迫抑制了桢楠幼树的生长,随着水分胁迫的加剧,植株出现不同程度的叶片发黄、下垂等症状;胁迫解除后,植株症状减轻,但水涝条件下植株存活率仅为56.38%;2)随着胁迫时间的延长,桢楠叶片超氧化物歧化酶(SOD)活性、可溶性蛋白(SP)含量、过氧化物酶(POD)活性和脯氨酸(Pro)含量呈先升后降的趋势,以水涝胁迫下变化幅度最为显著;3)在水分胁迫件下,桢楠幼树的MDA含量显著增多,整体变现为:水涝>水渍>干旱>对照。胁迫解除后,桢楠幼树MDA含量呈现下降趋势,植株表现出较强的抗旱能力和抗水渍能力;4)涝渍和干旱引起的水分胁迫会导致桢楠幼树的气孔导度(Gs)、净光合速率(Pn)和蒸腾速率(Tr)呈先降后升的趋势,且胁迫第50 d表现为水涝<水渍<干旱<对照,说明水涝对其伤害最深,但胞间CO2浓度(Ci)则表现为先升后降的趋势。综合各指标说明,桢楠幼树不耐长时间水涝,因此,在桢楠育苗中,应严格采取排水措施。To provide theoretical basis for the cultivation of Phoebe zhennan seedlings and the scientific water management of plantations,the photosynthetic characteristics of the seedlings were determined by using the two-set basin method to treat the seedlings with different degrees of water stress(waterlogging,water stains,natural conditions and drought).The results showed that:1)with the aggravation of water stress,the growth of young trees were inhibited,and the leaves of the plant appeared yellow and drooping in varying degrees.After the stress was relieved,the symptoms of the plants were alleviated,but the survival rate of plants was only 56.38%under waterlogging.2)Under water stress,the superoxide dismutase(SOD)and peroxidase(POD)activity,soluble protein(SP)content,proline(Pro)content of Phoebe zhennan leaves showed a trend of increasing first and then decreasing,and the change range was the most significant under waterlogging stress.3)Malondialdehyde(MDA)content in each treatment increased significantly with the prolongation of stress time,and the order of which was waterlogging>water stains>drought>natural conditions.The content of MDA showed a downward trend after the stress was relieved,and the plant showed strong drought resistance and water resistance ability.4)Water stress caused by waterlogging and drought resulted in the content of the stomatal conductance(Gs),net photosynthetic rate(Pn)and transpiration rate(Tr)of seedlings to rise and then fall.On the 50th day of stress,the content of Gs,Pn,Tr manifested as waterlogging<water stains<drought<natural conditions,which showed that waterlogging was the most harmful to seedlings,but the intercellular CO2 concentrationin(Ci)creased first and then decreased.According to all the above,the seedlings of Phoebe zhennan were intolerant of waterlogging for a long time,therefore,the drainage measures should be taken strictly in the seedling raising.

关 键 词：桢楠 水分胁迫 光合生理 生长特性 

分 类 号：S792.24[农业科学—林木遗传育种]