中文摘要：

罂粟科属间演化关系一直存在争议。本文以罂粟科罂粟属的虞美人（Papaver rhoeas）和东方罂粟（Papaver orientale）、白屈菜属的白屈菜（Chelidonium majus）以及紫堇属的地丁草（Corydalis bungeana）为材料，应用整体透明和石蜡连续切片的方法，在明场显微镜和偏光显微镜下对其幼苗期的结构及发育进行了观察。结果表明，3属植物幼苗子叶节区下部存在的单中柱类型各异：罂粟属为外始式二原型圆形单中柱，白屈菜属为外始式二原型近圆形单中柱，紫堇属为外始式二原型“S”形单中柱。3属植物的子叶脉序也存在区别：虞美人和东方罂粟具单一叶脉，无叶隙；白屈菜为环结曲行羽状脉；地丁草为基出完全顶聚脉。根据上述幼苗初生维管系统的结构，认为3属中罂粟属较为原始，白屈菜属较为进化，紫堇属更为进化。

英文摘要：

The evolutionary relationships of genera in Papaveraceae are particularly controversial. The structures and developments of seedlings in 4 species of 3 genera were studied with the methods of tissue cleaning and paraffin section in this paper. Representatives of genus Papaver are Papaver rhoeas and Papaver orientale, while Chelidonium majus and Corydalis bungeana are representatives of genera Chelidonium and Corydalis, respectively. The results indicate the haplostele types are different in the lower part of cotyledon node zone （CNZ） of three genera. Genera Papaver and Chelidonium are exarch diarch rotundity haplostele and rotundity-like haplostele, respectively, and genus Corydalis is exarch diarch ＂S＂- shape haplostele. And the cotyledon venations of three genera seedlings are distinct. Papaver rhoeas and Papaver orientale have only a single primary vein, and no leaf gaps existed on the cotyledon node. Chelidonium majus and Corydalis bungeana have Brochidodromous-Camptodromous-Pinnate venation and Basvenation, respectively. In terms of the evidence from the structures of primary vascular system of seedlings, the evolvement levels of three genera are that Papaver is more primitive, and Corydalis is the most developed.