润楠属植物叶片和枝条水力特征的协同关系  

Coordination between leaf and stem hydraulic characteristics in Machilus species

作　　者：陈昭 关心怡 曹坤芳 Chen Zhao;Guan Xin-Yi;Cao Kun-Fang(Guangxi University,State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Nanning 530004,China;Guangxi University,College of Forestry,Guangxi Key Laboratory for Forest Ecology and Conservation,Nanning 530004,China)

机构地区：[1]广西大学亚热带农业生物资源保护与利用国家重点实验室,南宁530004 [2]广西大学林学院森林生态与保育重点实验室培育基地,南宁530004

出　　处：《植物科学学报》2018年第5期729-735,共7页Plant Science Journal

基　　金：国家自然科学基金项目(31470469)~~

摘　　要：以润楠属(Machilus) 7种植物成年个体为材料,对其进行生理指标测定,并对它们的叶片水分供需关系以及木质部纹孔特征和导水效率之间的关联进行分析。结果显示,润楠属7种植物相比原始被子植物具有更高的叶脉密度(VD),叶脉密度为9.8～14.1 mm/mm^2;气孔密度(SD)与叶脉密度呈显著正相关,说明叶片水分供需存在协同关系;气孔密度与气孔大小(GLC)呈负相关;气孔越大的叶片其膨压丧失点(TLP)的绝对值越低。枝条边材比导率(Ks)较低,为0.13～1.87 kg·m^(-1)·s^(-1)·MPa^(-1),且种间差异较大。叶脉和气孔密度均与边材比导率呈正相关。边材比导率与纹孔膜面积、纹孔口面积以及纹孔口长短轴比例相关性不显著。研究结果表明润楠属植物虽然叶脉密度较高,且木质部水分供应和叶片结构具有协同关系,但木质部解剖结构较为原始,导管多具梯形穿孔板,导水效率低,只能适应比较湿润的生境。We measured several physiological traits of seven Machilus species to determine the relationship between leaf water supply and demand as well as the relationship between xylem pit characteristics and hydraulic efficiency.Results showed that the seven Machilus species had much higher vein density(VD)than primitive angiosperms,within a moderately high range(9.8-14.1 mm/mm 2),and a significant positive relationship between stomatal density(SD)and VD,indicating coevolution of leaf water supply and demand.Furthermore,SD was negatively correlated with guard cell length(GCL)and leaves with larger stomata had higher turgor loss points(TLP).Stem sapwood specific hydraulic conductivity(K s)was relatively low(0.13-1.87 kg·m-1·s-1·MPa-1),with rather large interspecific variation.Both VD and SD were positively correlated with K s,reflecting the water relationship between plant leaves and stems.No significant relationship was found between K s and pit membrane area(PMA),pit aperture area(OPPA),or pit aperture length to width(APF)ratio.Thus,although the Machilus species evolved relatively higher VD and there was coordination between xylem water supply and leaf structure,their xylem anatomical structure was still primitive,with low hydraulic efficiency,and the vessels had scalariform perforations,indicating they can only adapt to relatively humid habitats.

关 键 词：润楠属 水分供需 纹孔 进化 

分 类 号：Q945.17[生物学—植物学]