摘要
以质体为单位的愈伤组织ptDNA的荧光强度变化显示出了特有的规律性。结合光培养花粉白苗叶片质体结构的电镜观察及叶绿素等色素的测定等,这种规律性似提示花粉白苗的ptDNA由于发生了相继缺失而显示出高度异质性,花粉白苗的形成则在于其占优势ptDNA的严重缺失。花粉白苗ptDNA的这种相继缺失不是随机的,似反映了ptDNA顺序组织上的特点。故ptDNA发生缺失的潜在可能性具有普遍意义,它与父系细胞质体类核的消失存在着并行关系。花粉白苗的占优势ptDNA指导了植株的性状,而次要ptDNA亦在较小程度上显示出影响。
The variation of plastid DNA contents in terms of fluorescere intensities in three kinds of calli producing green and albino pollen plants as well as regenerated albinos exhibits respectively a characteristic regularity of its own. Together with the electron microscopic observation of leaf plastid structure and the result of chlorophyll determination, it is considered that such regularity in variation of ptDNA contents may be the result of their successive deletions during the course of dedifferentiation of pollen cells and the serious deletion of predominant pvDNAs leads to the formation of pollen albinos. It is likely that the successive deletions of ptDNAs are not random in nature but reflect the sequence organization of ptDNA, and the potentiality to suffer deletions of such kind may be of general significance. The characteristics of pollen albinos are mainly directed by the predominant ptDNAs, the minor pt DNAs however still possess some effects.
