日本毛连菜花粉及果实微形态特征的研究

Study on the Micromorphological Characters of Pollen and Fruit of Picris japonica Thunb.

利用光学显微镜和扫描电镜观察日本毛连菜的花粉及果实微形态结构。结果表明:花粉粒外壁刺状纹饰基部粗大,刺状突起呈环形排列或数个密集成群;网眼小且深,大小、形状相近;萌发孔3个,具大型瘤状突起,瘤状突起为脑纹状纹饰。果实有5～10余条高起的纵肋和5条较深的纵沟,纵沟贯穿果实两端。外果皮细胞狭长形、先端呈游离的指状突起,游离部分层叠环绕果实排列。果实石蜡切片,外果皮为一列波状弯曲的表皮细胞;中果皮由多列细胞组成,细胞壁极厚;内果皮为一列椭圆形细胞;种皮为两列狭长形薄壁细胞;子叶内含大量糊粉粒;无胚乳。结果反映了日本毛连菜花粉及果实微形态特征明显,可将其作为鉴别日本毛连菜的依据。

The micromorphological characters of pollen and fruit of Picris japonica Thunb were observed by applying light microscope（LM） and scanning electron microscope（SEM）.The results show that pollen extine of P.japonica Thunb.has thorn-like ornamentation,whose base is thick.The thorn-like protuberances are ring-shaped arrangement or dense clusters;Mesh is small and deep,both size and shape are similar;Three apertures with three large tumor-like protuberances which have brain striate ornamentation.The fruit has about five to ten longitudinal ribs and five deep furrow that across the fruit both sides.Exocarp cells are long and narrow,the tip of the finger-like protrusions are dissociative,finger-like protrusions arrangement were stacked around the fruit.Paraffin section of fruit,the exocarp is one list of wavy curved epidermal cells;The mesocarp consists of multicolumn cells,whose cell wall is very thick;The endocarp is a string of oval-shaped cells.Seed coat consists of two narrow-shaped parenchyma cells;The cotyledon contains a great quantity of aleurone grains,without endosperm.The results indicate that the micromorphological characters of pollen and fruit of P.japonica Thunb is obvious and it can be used as a basis to identify P.japonica Thunb.