甘蓝热胁迫叶片细胞的超微结构研究

高温胁迫引起植物体损伤是很常见的，人们已从多方面探讨高温胁迫对植物的影响，主要工作集中在生理生化、膜结构、热激蛋白及作物产量等方面［１—４］，超微结构的变化也有少量报道［５—７］。但目前要建立一个高温对植物体影响的模式还比较困难。本文探讨了甘蓝不同耐热品种叶片细胞超微结构在热胁迫后的差异，目的是建立植物耐热程度的细胞学指标，为育种工作者选育耐热性品种提供细胞学依据。材料和方法试验材料为甘蓝（Ｂｒａｓｓｉｃａｏｌｅｒａｃｅａｖａｒ．ｃａｐｉｔａｔａＬ．）耐热品种“夏光甘蓝”和感热品种“京丰甘蓝”。…

ULTRASTRUCTURAL STUDY IN LEAF CELL OF BRASSICA OLERACEA VAR. CAPITATA UNDER HEAT STRESS

Ultrastructural changes of the leaf cells in response to heat stress in thermo resistant cultivar and thermo sensitive cultivar of Brassica oleracea var. capitata L. were investigated. No ultrastructural change was shown in mesophyll cell of the thermo resistant cultivar. All membrane bound structure remained intact. However, the cell ultrastructure of thermo sensitive cultivar showed significant changes. One of the major effects of heat stress was the disruption of membrane structure. Chloroplasts and nucleus were extremely sensitive to heat stress.Chloroplasts rounded off in different extents and their outer membranes disappeared. Structural alteration of the thylakoid membrane were visualized. Large amount of plastoglobulis appeared within the chloroplast. Mitochondria were far more resistant to heat stress than chloroplasts. There was no distinct changes of mitochondria structure. Nucleus suffered from serious damage as heat caused disruption of nuclear envelope and condensation of nucleoplasm, showing, eventually, numerous fibrillar granulous material and irregularly shaped hollow spaces presented within the nucleus.