旋花科植物雄性细胞的细胞质DNA存在状况及其系统学意义

用DAPI荧光染色方法检测了旋花科4属4种植物——空心菜Ipomoea aquatica Forsk. 、茑萝 Qua- moclit pennata (Desr．)Boj．、月光花 Calonyction aculeatum(L．)House和日本菟丝子Cuscuta japonica Choisy 中生殖细胞和精细胞中细胞质DNA存在的状况。证明除日本菟丝子外，其余3种植物的雄性细胞中都 存在细胞质DNA。此外，在我们曾研究过的5种旋花科种植物的生殖细胞和精细胞中亦显示含有细胞质 DNA，因而可认为这是旋花科较普遍的特性，日本菟丝子精细胞中缺少细胞质DNA，可作为—个新的胚胎学证据，支持此属从旋花科分出独立为菟丝子科。

Distribution of the cytoplasmic DNA in male cells of the Convolvulaceae and its systematic significance

The distribution of cytoplasmic DNA in generative and sperm cells of four species in four genera in the Convolvulaceae, i.e., Calonyction aculeatum, Ipomoea aquatica, Quamoclit pennata and Cuscuta japonica, has been detected using DAPI fluorescent staining method. Cytoplasmic DNA is found to occur in generative and sperm cells of all the species except for Cuscuta japonica. This result, together with the previous reports that cytoplasmic DNA is also distributed in male cells of five species in Ipomoea, Pharbitis and Calystegia, may indicate that the presence of cytoplasmic DNA in generative and sperm cells is a general feature of the Convolvulaceae. The absence of such DNA in male cells in the genus Cuscuta supports the establishment of this genus as an independent family, the Cuscutaceae.