板栗林不同生境下八月竹叶片形态可塑性分析

Morphological Plasticity of Chimonobambusa szechuanensis Leaf in Different Habitats of Castanea mollissima Forests

为了认识引种栽培的八月竹叶片对不同生境的可塑性适应规律,在浙江省龙泉市板栗林套种八月竹示范基地内调查不同生境下(林窗、林内、纯竹林)八月竹的叶片形态特征,并采用标准主轴回归(SMA)分析不同生境下八月竹叶片形态之间的异速生长关系。结果表明:叶长、叶宽、叶周长和叶面积彼此之间关系的异速生长指数为0.820~2.051,其中仅叶长和叶周长间呈等速生长,其余5对关系均呈异速生长模式;各指标间关系的异速生长指数在不同生境条件下均没有显著差异,进一步分析得到不同生境下各指标间异速生长SMA主轴沿y轴或斜率方向上发生了极显著移动(P<0.01),主要有相同叶长下,叶面积为林内>林窗>纯林,叶片大小整体也呈现为林内>林窗>纯林。板栗林套种八月竹的不同生境条件对八月竹叶片形态特征间异速生长指数没有显著影响,但在叶片大小上发生了可塑性响应。

To understand the plasticity of the cultivated Chimonobambusa szechuanensis leaves as an adaptation to different habitats,we investigate the morphological characteristics of Ch.szechuanensis leaves in different habitats(forest window,forest floor and pure bamboo forest)at the demonstration base of Castanea mollissima forest in Longquan City,Zhejiang Province,and use standardized major axis(SMA)to analyze the anisotropic growth relationship between the leaf morphology indicators of Ch.szechuanensis in different habitats.The results show that the anisotropic growth indices for the relationships between leaf length,leaf width,leaf circumference and leaf area range from 0.820-2.051,and only the leaf length-leaf circumference pair shows isotropic growth while the other five pairs show anisotropic growth patterns.The anisotropic growth indices for the relationships of all the indicators have no significant difference in different habitats.Further analysis yields an extremely significant shift(P<0.01)in the major axis of the isochronous growth SMA along the y-axis or slope direction among the indicators in different habitats,and with the same leaf length,leaf area is ranked by forest floor>forest window>pure forest,and leaf size also follow the order of floor>forest window>pure forest.Different habitats where Ch.szechuanensis is intercropped in Castanea mollissima forest have no significant effect on the allometric growth index among the leaf morphological characteristics of Ch.Szechuanensis,but there is a plasticity response in leaf size.