盐胁迫对二倍体马铃薯叶超微结构的影响

选取经12次轮回选择适应长日照的二倍体马铃薯富利亚(Solanum phureja,PHU)与窄刀薯(S.stenotomum,STN)杂种(PHU-STN)耐盐无性系BD54-8和盐敏感无性系BD57-3为试验材料,研究其受盐胁迫后叶部细胞超微结构的差异。BD54-8和BD57-3的试管苗培养在含有NaCl浓度为0、30mmol·L-1的MS培养基,采用H-7650型透射电子显微镜观察、拍照。结果表明,BD54-8和BD57-3在未经盐胁迫时,细胞膜、叶绿体及线粒体均保持完整,超微结构没有差异。耐盐无性系BD54-8经盐胁迫后,细胞膜、叶绿体、线粒体仍清晰可见,超微结构没有明显变化;盐敏感无性系BD57-3经盐胁迫后,细胞膜受到严重破坏,叶绿体外形受损,内部出现空泡化现象,线粒体外膜模糊、嵴减少。由此可知,耐盐无性系BD54-8比盐敏感无性系BD57-3受到的破坏轻,细胞膜、叶绿体及线粒体可作为二倍体马铃薯耐盐性鉴定的细胞学指标。

Leaf ultrastructure of diploid potato under salt stress

In this research, two clones, salt tolerant BD54-8 and salt sensitive BD57-3, were used as materials selected out of a diploid hybrid population Solanum phureja (PHU)and S. stenotomum(STN), which undergone twelve cycles of recurrent selection for long day adaptation, and investigated for leaf cell ultrastructure of two clones under salt stress. BD54-8 and BD57-3 were grown on MS medium supple- mented with 0 and 30 mmol·L-1 NaCI, pH 5.8, and leaf was sampled 20 d later for fixation H-7650. Transmission electron microscope was used for observations and photos. The results showed that both BD54-8 and BD57-3, when without salt stress, the cell membrane, chloroplast and mitochondria were intact, and no difference in ultrastructue was found. For the salt tolerant clone BD54-8 when stressed under salt, the cell membrane, chloroplast, and mitochondria were clearly visible, and no obvious ultrastructural changes were found, while for salt sensitive clone BD57-3 when stressed under salt, the cell membrane was seriously damaged, chloroplast shape was impaired and inside vacuolated, and mitochondria became vague in outer membrane and deficient in cristae. These results suggested that the salt tolerant clone BD54-8 was much less impaired as compared with the salt sensitive clone BD57-3, and the cell membrane, chloroplasts and mitochondria could be used as cytological identification of salt tolerance of diploid potato.