14个类型流苏树叶片和叶柄解剖学特征的比较研究

Study on anatomical characteristics of leaves and petioles of 14 Chionanthus retusus bio-types

为系统地研究流苏树的分类、形态特征和解剖特征,对华北地区14个主要类型的流苏树的形态特征和叶片及叶柄的解剖学特征进行分析。形态比较结果表明:14个不同类型的流苏树在外观形态有显著差异,其树冠、枝姿、树皮性状和叶形等形态特征都有显著不同,反映类型间可能存在遗传分化;解剖结构的观察结果显示:1)14个类型流苏树叶片均为异面叶,表皮细胞和栅栏组织均为1层,排列紧密,叶片和叶柄表面均覆有毛被和角质层;2)叶片和叶柄横切面结构有差异,叶柄中部横切面形状均为近半圆形,但维管束轮廓有近半圆形、半圆形和近圆形3种形状;3)维管束类型均为近周韧,但每个类型的维管束数目和大小都不尽相同。并根据筛选出的19个解剖特征数据对14个类型流苏树的分化关系进行聚类分析。综合比较形态和解剖特征可以发现在各类型之间差异比较明显,可为流苏树的类型鉴定及植株选优提供依据,在株型定向培育和资源鉴定方面具有一定的理论和应用价值。

In order to systemically study the classification,morphological and anatomical characteristics of Chionanthus retusus,the morphological characteristics and anatomical characteristics of leaves and petioles of 14 main bio-types of C.retususin North China were analyzed.The morphological results showed the morphological characteristics of different C.retusus types were significantly different,and their canopy,stance of branches,bark traits and leaf shape were significantly different.These results reflected possible genetic differentiations among different bio-types.The observation of anatomical structures showed that：1）Leaves of 14 C.retusus bio-types were typical dorsiventral leaf type,epidermal cells and palisades were both monolayer with close arrangement,and the blade of leaves and the surface of petioles were covered with hairs and cuticle.2）There were differences in the structures of different C.retusus biotypes in the transverse sections of leaves and petioles.The shapes of transverse sections in the middle part of petioles were all nearly semi-rotundity,but the vascular profiles were different and could be divided into three types,nearly semirotundity,semi-rotundity and nearly rotundity.3）The vascular stands were almost amphicribral,but the number and size in each bio-type of vascular stands were different.Of 19 anatomical features screened,the differentiation relationship of14 C.retusus bio-types was studied by cluster analysis.Through comprehensive comparison of morphological features and anatomical characteristics,we found that there were obvious differences among different bio-types,it could be usedas an important basis for its identification of bio-type.The results of our study could provide the basis for the identification and plant selection of C.retusus,and it also had theoretical and practical value in strain orientation and resource identification.