干旱胁迫对花椰菜叶片细胞保护酶及超微结构的影响

观察比较了干旱胁迫下不同花椰菜品种叶片过氧化物酶 (POD)、硝酸还原酶 (NR)活性及细胞超微结构的差异 ,结果表明 :干旱胁迫后各品种POD活性提高。早、中熟品种NR活性下降 ,晚熟品种NR活性提高。早、中熟品种叶绿体变圆 ,片层弯曲、解体 ,淀粉粒消失 ,嗜锇颗粒变为空腔 ,线粒体嵴及其内、外膜解体 ,晚熟品种叶绿体片层模糊、稀疏 ,线粒体结构无明显变化

The Effects of Drought Stress on Cell-Protecting Enzymes and Ultrastructure of Cauliflower Leaf Cells

The differences of various cauliflower cultivars in leaf activities of peroxidiase and nitrate reductase and cell ultrastructure under drought stress were investigated. The results showed that under drought stress,POD activity in all cultivars increased while NR activity increased only in late maturing cultivars and decreased in early and mid maturing cultivars. The changes of chloroplasts and mitochondria also varied with cultivars. In early and mid maturing cultivars,the chloroplasts became more round and the plates inside distorted or even disintegrated with the starch particles disappeared and plastoglobulis became empty inside,the cristae and the inner and outer membrane disintegrated. However,in the late maturing cultivars plates of chloroplasts became less clear in shape and thinner in density,with no obvious change in structure of mitochondria.