【摘要】 在-9℃冰冻两天后,抗寒性强的“农科一号”品种的叶片细胞的精细结构没有发生明显的改变,植株在化冻后立即恢复正常状态。抗寒性中等的“郑州741”品种的细胞亚显微结构表现出明显的但还是可逆的变化,其叶绿体不同程度的变圆,片层排列方向发生改变,类囊体轻度空泡化,但叶绿体的外部被膜仍保持完整;液泡膜向内反卷;核的染色质凝集成较大的质块。不耐寒的春小麦品种“京红8号”叶片细胞的细微结构受到严重的破坏,叶绿体解体,细胞质和细胞核中形成大量小泡,线粒体的内嵴也遭受破坏,这些变化是不可逆的,从而导致植株死亡。更多还原

【Abstract】 After the plants of three wheat varieties with different cold resistance were frozen for two days at -- 9℃ and then thawed at room temperature, the freezing injury and recovery expression of shoots and ultrastuctural changes of their leaf cells were com- pared. The results obtained are summarized as follows: The fine structufe in leaf cells of hardy variety Nongke No. I did not produce visible changes, and the plants recovered to normal morphology immediately after thawing. The cell ultrastructure of mediate-hardy variety Zhengzhou No. 741 showed signi- ficant changes which were reversible. The chloroplasts became round by different de- grees, parallel arrangement of the lamellae in chloroplast was altered, and the thyla- koid produced some vesicles, but the chloroplast envelope was still intact. The tono- plast exhibited infolded and engulfed structure. Nuclear chromatin was coagulated to form bigger mass. The fine structure in leaf cells of non-hardy variety Jinghong No. 8 was severely destroyed. The chloroplasts were disintegrated. A lot of vesicles were formed in cytoplasm and nuclei. Mitochondria cristae were also disrupted. These changes are irreversible and lead to death of plants.更多还原