中文摘要：

为进一步探讨小麦叶片细胞结构和表面糖蛋白与抗寒性的关系,以春性品种扬麦16和半冬性品种徐麦30为材料,对低温处理后小麦叶片细胞结构和表面糖蛋白的变化进行了标记定位电镜观察.结果表明,分蘖期两品种冻害率随低温胁迫程度的加重而逐渐升高,扬麦16抗寒性弱于徐麦30.-6和-10℃低温胁迫24 h后,扬麦16叶片薄壁细胞出现了质壁分离现象,徐麦30未发生质壁分离;低温胁迫48和72 h后,随着胁迫时间的延长,两品种的叶绿体、线粒体以及细胞膜系统被破坏的程度均加重,表现为叶绿体、线粒体肿胀呈圆形,类囊体排列方向不规则,细胞内出现空泡化现象,内含物外泄,部分细胞器消失.低温胁迫后两品种叶片组织细胞表面均出现一层起保护作用的薄糖蛋白层,结构疏松呈丝状,徐麦30细胞表面糖蛋白层的保持时间长于扬麦16.随着处理温度的降低和胁迫时间的延长,两品种叶片细胞结构均受到严重破坏,细胞壁表面糖蛋白大部分脱落到细胞间隙中或凝集成块状进入细胞内部.说明低温胁迫造成小麦细胞结构以及表面糖蛋白发生不同程度的变化,是不同小麦品种抗寒性存在差异的生理原因之一.

英文摘要：

Cytochemical changes of glycoproteins localized at the cell surface and the cell structure in the leaves of wheat were observed by electron microscopy using Yangmai 16 and Xumai 30 as materials treated under low temperature to explore the their relations with cold tolerance. The results showed that the freezing-injured rate increased with lower temperature and longer duration of stress. Yangmai 16 had weaker resistance to low temperature than Xumai 30. Plasmolysis occurred in the cells when Yangmai 16 was treated with --6 ~C and --10 ~C for 24 h, while Xumai 30 did not. Under longer du- ration of lower temperature, the chloroplasts became swollen and round, the arrangement directions of thylakoid changed and cell cavitation was observed, part of the organelles disappeared, even noth-ing could be observed in the cells. At the beginning of low temperature treatment, a few glycoproteins were attached to the diachyma cytoderm, which appeared loose filamentous structure. The keeping time of the glycoproteins attaching the cell surface of Xumai 30 was longer than that of Yangmai 16. The longer the low temperature was, the more serious the cold damage on cells of both cultivar plants was. The cell surface glycoproteins appeared to move into the intercellular spaces or inside the cell. The different changes of cell structure and surface glycoproteins were one of the physiological reasons of wheat cultivars with different cold hardiness.