摘要
【目的】研究破布木冬、夏季光合速率和相关影响因子的日变化规律及测定其微量元素含量,为破布木的人工栽培和药用价值开发提供参考依据。【方法】采用LCi-SD便携式光合仪测定破布木的净光合速率(Pn)及其相关因子[光合有效辐射(PAR)和气孔导度(Gs)等]的日变化规律,并利用电感耦合等离子体质谱法(ICP-MS)测定破布木一年生枝条、二年生枝条和叶片的Cu、Fe、Zn、Mn、Cr、Se和Co含量。【结果】破布木冬季的Pn和蒸腾速率(Tr)日变化峰值均出现在10:00,分别为8.62μmol/(m^2·s)和3.86mmol/(m^2·s);夏季的Pn和Tr最高峰均出现在上午10:00,分别为8.60μmol/(m^2·s)和5.17mmol/(m^2·s),午间出现光合午休现象,次高峰出现在14:00,分别为5.31μmol/(m^2·s)和3.68mmol/(m^2·s);冬季与夏季的PAR峰值分别出现在10:00和12:00[1027和1685μmol/(m^2·s)];无论是冬季还是夏季,上午破布木的Gs明显高于下午,整体上呈下降趋势。相关性分析结果表明,破布木叶片冬、夏季的Pn与Tr均呈极显著正相关(P<0.01,下同),Tr与Gs和相对湿度(RH)均呈显著正相关(P<0.05,下同);冬季的Pn与PAR、Gs呈显著正相关。与胞间CO2浓度(Ci)、RH和大气CO2浓度(Ca)无显著相关性(P>0.05,下同);Tr与PAR、Gs和RH呈显著正相关;RH与PAR呈显著正相关。夏季的Pn与Gs呈极显著正相关,与RH呈显著正相关,而PAR、Ci和Ca与Pn无显著相关性;Tr与Gs和RH呈显著正相关;RH与Gs呈显著正相关。破布木富含Fe、Zn和Mn元素,且在叶片中的含量最高,分别为133.19、13.68和76.30mg/kg,明显高于Cr、Se和Co元素,Cr、Se和Co含量均低于0.40mg/kg;Fe、Zn、Mn、Cr、Se和Co元素的富集部位排序为叶片>一年生枝条>二年生枝条,而Cu的富集部位排序为一年生枝条>叶>二年生枝条。【结论】破布木冬季的Pn与Tr日变化呈单峰形曲线,其Tr、PAR和Gs是影响冬季Pn日变化的主要因素;夏季的Pn与Tr日变化呈双峰形曲线,其Tr、RH和Gs是影响夏季Pn日变化的主要因素。破布木的Fe、Mn和Zn等微量元素含量相对较高,具有与治疗风湿病常用中药一致的高微量元素含量特征。
【Objective】In this paper,the diurnal variation tendency of the photosynthetic rate and related influencing factors of Cordia dichotoma Forst. f. in winter and summer were studied,and the contents of trace elements in the plant were determined. The results could provide a basis for the artificial cultivation and development of medicinal value of the plant.【Method】The diurnal variation of net photosynthetic rate(Pn)and its related influencing factors[photosynthetic active radiation(PAR)and andstomatal conductance(Gs)]were measured by LCi-SD portable photosynthetic instrument. The contents of Cu,Fe,Zn,Mn,Cr,Se and Co in annual branches,biennial branches and leaves of C. dichotoma were determined by inductively coupled plasma atomic emission spectrometry(ICP-MS).【Result】The diurnal peak value of Pn and transpiration rate(Tr)in winter were 8.62 μmol/(m^2·s)and 3.86 mmol/(m^2·s)at 10:00 am,respectively. In summer, the peak of Pn and Tr occurred at 10:00 am,maximum Pn value was 8.60 μmol/(m^2·s),maximum Tr value was 5.17 mmol/(m^2·s),midday depression phenomenon occurred at noon,and their sub-peak value were 5.31 μmol/(m^2·s)and 3.68 mmol/(m^2·s)at 14:00 pm,respectively. PAR peak occurred at 10:00 am and 12:00 am respectively in winter and summer[1027 and 1685 μmol/(m^2·s)]. In both winter and summer,Gs in the morning was higher than that in the afternoon, showed a downward trend. The results of correlation analysis showed that the Pn of C. dichotomain winter and summer were extremely significant positively correlated with Tr(P<0.01,the same below),Tr significantly positively correlated with Gs and relative humidity(RH)(P<0.05,the same below). In winter,Pn was extremely positively correlated with PAR,and significantly positively correlated with Gs,and had no significant correlation with intercellular CO2 concentration (Ci),RH and atmospheric CO2 concentration(Ca)(P>0.05,the same below). Tr was significantly positively correlated with PAR,and Gs was significantly correlated with RH. RH was significant positive correlated with PAR. In summer,Pn was extremely positively correlated with Gs and RH,and there was no significant correlation between PAR and Pn,between Ci and Pn,between Ca and Pn,Tr was significantly correlated with Gs and RH,RH was significantly positively correlated with Gs. C. Dichotoma contained abundant Fe,Zn and Mn elements,the contents of Fe,Zn and Mn in the leaves were the highest(133.19,13.68 and 76.3 mg/kg respectively),which was significantly higher than that of Cr,Se and Co;and the contents of Cr,Se and Co were all lower than 0.40 mg/kg. The concentration of Fe,Zn,Mn,Cr,Se and Co elements in the C. dichotomas howed as:leaves>annual branches>biennial branches,while Cu accumulation trend showed as: annual branches>leaves>biennial branches.【Conclusion】The diurnal variations of Pn and Tr in C. dichotoma in winter represent a single-peak curve,and Tr,PAR and Gs are the main factors to affect the diurnal variations of Pn in winter. The diurnal variations of Pn and Tr in C. dichotoma in summer represented a bimodal curve,and Tr,RH and Gs are the main factors to affect the diurnal variations of Pn in summer. The contents of trace elements such as Fe,Mn and Zn in C. dichotoma are high,which is consistent with the characteristics of high trace element content in traditional Chinese medicine commonly used in treating rheumatism.
作者
肖钰
杨浩
韩维栋
XIAO Yu;YANG Hao;HANWei-dong(College of Agriculture,Guangdong Ocean University,Zhanjiang,Guangdong 524088,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2019年第9期2045-2051,共7页
Journal of Southern Agriculture
基金
广东省林业科技创新项目（2019003）
中央财政支持地方高校发展专项（粤财教〔2017〕263号）
关键词
破布木
光合速率
日变化
相关分析
微量元素
Cordia dichotoma Forst. f.
photosynthetic rate
diurnal variation
correlation analysis
trace elements
