植物亲缘关系影响植物叶蜡正构烷烃的含量和分布特征  

EFFECT OF PHYLOGENETIC RELATIONSHIPS ON CONCENTRATION AND DISTRIBUTION OF LEAF WAX N-ALKANES

作　　者：石敏锐 韩家懋[2] 周力平[3] 王国安[1] 李嘉竹 SHI Minrui;HAN Jiamao;ZHOU Liping;WANG Guo'an;LI Jiazhu(College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;College of Urban and Environmental Sciences,Peking University,Beijing 100871;Institute of Desertification Studies,Chinese Academy of Forestry,Beijing 100091)

机构地区：[1]中国农业大学资源与环境学院环境科学与工程系,北京100193 [2]中国科学院地质与地球物理研究所,北京100029 [3]北京大学城市与环境学院,北京100871 [4]中国林业科学院荒漠化研究所,北京100091

出　　处：《第四纪研究》2021年第4期986-999,共14页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:41772171)资助。

摘　　要：沉积物中的长链正构烷烃主要来自陆生高等植物叶蜡,在古环境重建中有着广泛应用。植物叶蜡正构烷烃的含量和分布特征受植物遗传因素控制。尽管前人对遗传因素的影响有报道,但还没有学者从植物系统进化发育学的角度来揭示植物的亲缘关系对植物叶蜡正构烷烃含量和分布特征的影响。为此,本研究选择了气候差异显著的北京东灵山(温带半湿润气候)和宁夏沙坡头(温带干旱气候)作为植物样品采集地点,于2004~2019年每年9月中旬进行样品采集,通过超声提取法分离植物叶片的叶蜡正构烷烃并进行测定。结果显示,两个地区相同科的植物主峰碳(C_(max))分布相似,叶蜡正构烷烃总量(Σalk)和碳优势指数(CPI)存在显著性差异(p<0.05),东灵山Σalk和CPI的平均值分别是393μg/g和12,沙坡头是952μg/g和15。两个地区的平均碳链长度(ACL)没有显著性差异(p>0.05),东灵山的ACL是29.4,沙坡头是29.6。本研究还发现东灵山和沙坡头地区都存在着不同科植物之间的叶蜡正构烷烃含量和分布特征具有显著差异,同一科不同属植物间差异相对较小,同一属不同种植物之间基本一致的规律,表明植物正构烷烃在植物间的分布基本上符合生态位保守理论,即亲缘关系越近的植物其叶蜡正构烷烃分布特征越相似,呈现出较强的系统发育保守性。由于两个地区都存在这样的规律,说明该规律不会受到局地气候环境的影响,具有普适性的意义。这在古环境重建中的意义是,当利用沉积物正构烷烃信号重建古环境时,除了考虑气候变化对植物叶蜡正构烷烃的直接影响,也应考虑气候变化会导致植物种类发生变化,从而改变正构烷烃含量和分布特征,最终影响沉积物中的正构烷烃信号。另外,沉积物正构烷烃信号与其他指标,如孢粉相结合,有可能提供植物群落结构变化的准确信息。The long-chain n-alkanes in sediments mainly come from terrestrial higher plant leaf waxes and are widely used in paleoenvironmental reconstructions.The concentration and distribution of leaf wax n-alkanes are affected by plant genetic factors.Although there have been reports on the influence of genetic factors,the effect of phylogenetic relationships on the concentration and distribution of plant leaf waxes n-alkanes has never been studied by using phylogenetics.This study selected two locations with obvious climate differences,Dongling Mountain in Beijing,China(39°56'N,115°32'E,temperate subhumid climate)and Shapotou in the Ningxia Hui Autonomous Region,China(37°28'N,105°06'E,temperate arid climate)as plant collection sites where plant leaves were sampled in mid-September from 2004 to 2019.During these years,331 samples were collected in Dongling Mountain and 94 samples were collected in Shapotou.The wax n-alkanes were ultrasound,extraction and measured.In Dongling Mountain,theΣalk ranged from 0.66μg/g to 5155μg/g with a mean value of 393μg/g,the CPI from 1.87 to 48.4 with a mean value of 12,and the ACL from 26.7 to 32.1 with a mean value of 29.4.In Shapotou,theΣalk varied 50μg/g to 11533μg/g with a mean of 952μg/g,the CPI from 1.96 to 55.1 with a mean of 15,and the ACL from 27.3 to 31.4 with a mean of 29.6.Between the two sites,there were significant differences inΣalk and CPI values(p<0.05),but there was no difference in ACL values(p>0.05).The present study showed that the plants within the same family were similar in main peak carbon(C_(max)),carbon preference index(CPI)and average chain length(ACL),but different in total n-alkane concentration(Σalk)for both regions.C31 is the C_(max) in all samples pooled and in Compositae for two sites.Furthermore,the differences in concentration and distribution of leaf waxes n-alkanes were significant across different families(p<0.01),but relatively small across different genera within the same family,and basically the same across different plant species wi

关 键 词：植物叶蜡正构烷烃 含量和分布特征 亲缘关系 局地气候 

分 类 号：P593[天文地球—地球化学] Q948[天文地球—地质学]