黄独冻后黑暗培养胚性愈伤组织及其再生植株的电镜观察

The Electron Microscope Observation of Embryogenic Calli Cultured in Darkness after Cryopreservation and Its Regenerated Plantlets of Dioscorea bulbifera L.

本研究以黄独为材料,对其冻后黑暗培养胚性愈伤组织及其再生植株进行电镜观察。结果表明:黄独胚性愈伤组织在冻后没有经过一定时间的黑暗培养直接放于正常的光周期下培养,极易使细胞内容物外泄,且造成部分细胞器和细胞核消失或裂解形成空隙,线粒体和高尔基体等细胞器的结构不完整,出现空隙或内容物溢出或断裂现象;而黄独冻后胚性愈伤组织经过3 d的黑暗培养后再置于光周期下培养,受损的细胞较少,细胞排列较紧密,且细胞器降解较少,很少出现空隙等现象,线粒体、高尔基体等细胞器的结构也较为完整。此外,与黄独带芽茎段常温继代再生试管苗相比,黄独胚性愈伤组织经过冻后黑暗培养后,其再生试管苗的根、茎、叶结构没有出现显著变化,且两者的气孔参数和叶绿体数量也均无显著性差异。本试验结果可为植物种质资源超低温保存后的黑暗培养提供了亚显微结构证据。

Using Dioscorea bulbifera L.as materials,its embryogenic calli cultured in darkness after cryopreservation and its regenerated plantlets were observed with electron microscopy in this paper.Embryogenic calli of D.bulbifera L.being cultured directly in the photoperiod without dark culture after cryopreservation If would caused the leakage of cell contents,the disappearance and cracking of some organelles and nuclei,the incomplete structures of mitochondria and Golgi complexes and the emergence of the phenomenon of void,content overflow and fracture.When embryogenic calli of D.bulbifera L.were cultured firstly in the dark for 3 d and then in the photoperiod after cryopreservation,the damaged cells were less,the cells were arranged closely,the organelles were less degraded,and there were few voids,and the structure of organelles such as mitochondria and Golgi complexes were more complete.In addition,the structure of roots,stems and leaves between plantlets regenerated from embryogenic callus cultured in dark culture after cryopreservation and plantlets subcultured at room temperature of D.bulbifera L.showed no changes,whose stomatal parameters and chloroplast number had no significant difference.The results of this study can provide submicroscopic structural evidences for dark culture after cryopreservation of plant germplasm resources.