中亚热带樟科3种植物幼苗叶结构型性状的种间差异及其相关性

Interspecific Differences and Correlation among Leaf Structural Traits of Three Plant Seedlings of Lauraceae in the Mid-Subtropical Zone of China

为了揭示植物叶功能性状对全球气候变化的响应和适应规律,以樟科3种植物幼苗为研究对象,将其人工采集的种子经低温沙藏并于温室培育,然后将幼苗移栽到野外同质园中自然生长,研究中亚热带樟科植物刨花楠(Machilus pauhoi)、香樟(Cinnamomum camphora)和闽楠(Phoebe bournei)两年生幼苗生长季节9种叶结构型性状的种间差异及其相关性。结果显示,(1)在3种植物幼苗中,香樟叶面积、叶厚度、叶体积、叶氮磷比最大,叶氮浓度最高,叶组织密度最小;闽楠叶组织密度、叶干物质含量最大,叶磷浓度最高,叶面积、叶体积、比叶面积、叶氮磷比最小,叶氮浓度最低;刨花楠比叶面积最大,叶厚度、叶干物质含量最小,叶磷浓度最低;3种植物幼苗的叶厚度之间均无显著差异。(2)Pearson相关分析和线性回归分析结果表明,樟科3种植物幼苗的叶面积与叶体积间呈极显著正相关(P<0.01)、与叶干物质含量间呈极显著负相关(P<0.01)、与叶磷浓度间呈极显著负相关(P<0.01)、与叶组织密度间呈显著负相关(P<0.05)、与叶氮浓度间呈显著正相关(P<0.05);叶厚度与比叶面积间呈显著负相关(P<0.05)、与叶干物质含量间呈显著正相关(P<0.05);叶体积与叶组织密度间呈极显著负相关(P<0.01)、与叶氮浓度间呈极显著正相关(P<0.01)、与叶磷浓度间呈显著负相关(P<0.05);叶组织密度与叶磷浓度间呈显著正相关(P<0.05);比叶面积与叶干物质含量间呈极显著负相关(P<0.01)、与叶磷浓度间呈极显著负相关(P<0.01);叶干物质含量与叶磷浓度间呈极显著正相关(P<0.01)。这表明在同质园中生长的刨花楠、香樟和闽楠幼苗的9种叶结构型性状表现出一定的种间差异,不同物种同一叶结构型性状指标的大小顺序、种间差异及其显著性不同;3种植物幼苗不同叶结构型性状之间的相关性及其显著程度也不同。本研究结果为揭示樟科3种植物幼苗叶功能性状对全球气候变化的响应和适应规律提供了基础数据。

Following manual collection of seeds stored in sand under low temperature and thencultivated in greenhouse, Machilus pauhoi, Cinnamomum camphora and Phoebe bournei（Lauraceae）seedlings from the mid-subtropical zone of China were transplanted to the common garden in the Jiangxi Dagangshan Forest Ecosystem Research Station.Interspecific differences and correlations in leaf size,leaf thickness,leaf volume,leaf tissue density,specific leaf area,leaf dry matter content,leaf nitrogen concentration,leaf phosphorus concentration,and ratio of nitrogen and phosphorus concentration of two-year old seedlings in the growing season were investigated to provide basic data and scientific reference material on the responses of the leaf functional traits to global climate change.Results showed that：（1）Among the three plant seedlings,leaf size,leaf thickness,leaf volume,leaf nitrogen content and ratio of leaf nitrogen and phosphorus concentration were highest in C.camphora,and leaf tissue density was lowest.Leaf tissue density,leaf dry matter content and leaf phosphorus concentration were highest in P.bournei,while leaf size,leaf volume,specific leaf size,ratio of leaf nitrogen and phosphorus concentration,and leaf nitrogen content were lowest.Specific leaf area was highest in M.pauhoi,while leaf thickness,leaf dry matter content,and leaf phosphorus concentration were lowest.Leaf thickness of the three plant seedling species showed no significant differences;（2）Pearson and line regression analyses indicated that leaf size showed highly significant positive correlation with leaf volume（P〈 0.01）,and highly significant negative correlation with leaf dry matter content and leaf phosphorus concentration（P〈 0.01）.The correlations between leaf size and leaf tissue density and leaf nitrogen concentration were significantly negative and positive,respectively（P 〈0.05）.The correlations between leaf thickness and specific leaf area and leaf dry matter content were significantly negative and positive,respectively（P〈 0.05）.The correlations between leaf volume and leaf tissue density and leaf nitrogen concentration were highly significantly negative and positive,respectively（P 〈0.01）.Leaf volume also showed significant negative correlation with leaf phosphorus concentration（P 〈0.05）.Leaf tissue density showed significant positive correlation with leaf phosphorus concentration（P 〈0.05）.Specific leaf area exhibited highly significant positive correlation with leaf dry matter content and leaf phosphorus concentration,respectively（P〈 0.01）.Leaf dry matter content showed highly significant positive correlation with leaf phosphorus concentration（P 〈0.01）.The nine leaf structural traits of the three plant seedlings of Lauraceae exhibited certain interspecific differences,but the order and significance were different.Furthermore,the correlations and significance of the nine leaf structural traits of the three plant seedlings were different.