银扇草果实假隔膜的形态发育特征

Morphological characteristics of the development of false dissepiment in Lunaria annua

采用形态学和细胞学方法对银扇草果实假隔膜的形态、发育过程和显微结构特征进行初步研究。发现银扇草果实假隔膜起源于腹缝线假隔膜原基,它的发育历经雏形期、延展期和成熟期3个时期;假隔膜由表皮细胞和内层薄壁细胞构成;雏形期假隔膜呈沙漏状,薄壁细胞富含褐色小体;延展期假隔膜呈杠铃状,薄壁细胞逐渐解体,形成较大的空腔;成熟期假隔膜呈典型的线型结构,薄壁细胞基本退化,仅剩2层表皮细胞;完全成熟的假隔膜近圆扇形,表皮细胞排列有平行、倾斜、垂直等方式,外壁具银色覆饰物;银扇草果实的假隔膜极度发达,随果实协同发育,属背腹扁平型。发达的假隔膜的形成可能与银扇草果实较大、种子较少有关。

In this study,morphological and cytological methodologies were applied to preliminarily study the cytogenesis,development and microstructural characteristics of the special morphology of the false dissepiment of Lunaria annua.It was found that the false dissepiment originates from the false dissepiment primordium on the ventral suture.Its development had embryonic stage,extension stage and mature stage.False dissepiments consist of epidermal cells and inner parenchyma cells.At embryonic stage,the false dissepiment shaped hourglassly and the parenchyma cells were rich in brown bodies,while false dissepiments was barbell shaped at extension stage,and the parenchyma cells gradually disintegrated,forming a large cavity.False dissepiments showed a typical linear structure at ripe stage,and the parenchyma cells basically degenerated,leaving only two layers of epidermal cells.The fully mature false dissepiments was nearly round-fan-shape,with epidermal cells arranged in parallel,inclined and vertical ways,and the outer wall was adorned with silver decorations.False dissepiments of Lunaria annua was extremely developed,and developed synergistically with the fruit,belonging to the flattened dorsally type.The formation of highly developed false dissepiment might be related to larger fruits and fewer seeds.