文献类型：期刊文献

中文题名：秋茄幼苗光合特性对寒害的响应

英文题名：Responses of Leaf Photosynthetic Characteristics of Kandelia obovata Seedlings to Chilling

作者：郭菊兰[1] 朱耀军[1] 文菀玉[1] 武高洁[1] 宁宇[1] 马骅[1] 王义飞[1]

第一作者：郭菊兰

机构：[1]中国林业科学研究院湿地研究所湿地生态功能与恢复北京市重点实验室

年份：2018

卷号：31

期号：6

起止页码：63-68

中文期刊名：林业科学研究

外文期刊名：Forest Research

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2017_2018】；

基金：国家林业公益性行业科研专项:红树林寒害及富营养化监测预警与灾害评价(201504419);清澜港红树林土壤N2O通量排放特征(CAFYBB2016SY033)

语种：中文

中文关键词：秋茄幼苗;低温胁迫;光合特征;荧光特征

外文关键词：Kandelia obovata seedlings;low-temperature stress;photosynthetic characteristics;fluorescent characteristics

分类号：S718.3

摘要：[目的]研究低温胁迫对秋茄幼苗光合作用和叶绿素荧光参数的影响及秋茄幼苗对低温胁迫的防御机制,以期为抗寒性红树植物种的选育、引种提供参考。[方法]以秋茄幼苗为材料,分别在5℃与12℃低温下进行胁迫试验。应用Li-6400XT便携式光合作用测定仪和便携式脉冲调制叶绿素荧光仪(PAM-2500)分别测定光合参数与叶绿素荧光参数的变化,应用EXCEL和SPSS13. 0软件进行数据整理、作图及统计分析。[结果]表明:(1)低温胁迫对秋茄幼苗的光合速率(Pn)、胞间CO2浓度(Ci)、气孔导度(Gs)及水分利用率(WUE)影响显著(P <0. 05);(2)低温胁迫下,Pn、Gs、Ci均显著降低,持续5 d低温,Pn、Gs随低温时间的延长持续下降,Ci则呈现上升趋势。5℃低温胁迫第1天,WUE明显高于对照(CK),第2天之后开始下降且低于对照(CK); 12℃低温胁迫下,WUE略高于CK且低温期内持续高于CK。(3) 5℃低温胁迫下,可变荧光(Fv)与最大光能转换速率(Fv/Fm)低于CK,随低温时间的延长呈现下降趋势,在低温第5天,显著低于CK(P <0. 05); 12℃低温胁迫下,Fv和Fv/Fm变化不明显。[结论]秋茄幼苗可在12℃低温胁迫下存活,但秋茄幼苗的形态生长和生物产量减少,而5℃低温胁迫持续2 d是秋茄幼苗的生存阈值;秋茄幼苗叶片在未使光系统Ⅱ(PSⅡ)潜在活性中心受损的低温胁迫下,Pn下降主要受气孔因子限制,在光合作用过程中,通过提高叶片水分利用率,以减少光合速率下降,提高抗寒能力。
[Objective]To investigate the effects of chilling on leaf photosynthesis and chlorophyll fluorescence parameters in mangrove Kandelia obovata seedlings,and the defense mechanism of K.obovata seedlings against chilling,so as to provide references for the breeding and introduction of the cold-resistant mangrove species.[Method]Under low-temperature stress at 5℃and 12℃,the changes of leaf photosynthetic parameters and chlorophyll fluorescence parameters of K.obovata seedlings were measured using portable photosynthesis analyzer(Li-6400XT)and portable pulse modulated chlorophyll fluorescence instrument(PAM-2500),respectively.Data processing,mapping and statistical analysis were carried out using the software EXCEL and SPSS13.0.[Result](1)The leaf photosynthetic rate(Pn),intercellular CO 2 concentration(Ci),stomatal conductance(Gs)and water use efficiency(WUE)of K.obovata seedlings were significantly affected by low temperature stress(P<0.05).(2)At low temperature,the values of Pn,Gs and Ci decreased significantly,and the values of Pn and Gs showed a decreasing trend during 5 days of low temperature while the Ci showed a rising trend.Under the low-temperature stress at 5℃,the value of WUE was higher than CK at the first day,and then decreased to lower than CK.At 12℃,WUE was a little higher than CK during all the 5 days.(3)At 5℃,the variable fluorescence(Fv)and the maximum light energy conversion rate(Fv/Fm)were lower than CK,and showed a downward trend with the time duration of low temperature,and decreased significantly at low temperature at the fifth day(P<0.05).At 12℃,the changes of Fv and Fv/Fm values were not significant.[Conclusion]K.obovata seedling can survive under low-temperature stress at 12℃,and the growth and biomass of K.obovata seedlings will decrease.At the low temperature of 5℃,the survival threshold of K.obovata seedlings is 2 days(48 h).Under low-temperature stress which does not damage the potential activities of leaf Photosystem II(PSII)in K.obovata seedlings,the declining of Pn is mainly because of the restricted stomatal efficiency(WUE).During the process of photosynthesis,K.obovata seedlings will lower the declining of photosynthetic rate through increasing the leaf water use to improve its cold-resistance ability.