大白菜干烧心病的形态结构及生理生化变化

以人为诱发大白菜(Brassica Campestris L.ssp.pekinensis(Lour)Olsson.)干烧心病的方法,研究了该病发生发展过程中叶片形态结构及生理生化的变化。结果表明:随着叶片中钙含量的下降,干烧心病症逐渐出现。在此过程中,光合强度降低,膜受损伤,糖含量及电解质外渗率渐增,粘液外溢于叶表;解剖结构观察可见质膜内陷,有囊状小泡形成,细胞器逐步解体;随之,可溶性果胶剧增,胞壁损伤,最后细胞解体死亡,残存固形物充塞了胞壁内外。对叶片排水器黑变与干烧心病发生的独立性检验,表明二者无相关性。

Morphological, Structural, Physiological and Biochemical Changes during the Development of Tipburn Symptoms in Chinese Cabbage

The morphological, structural, physiological and biochemical changes during development of the tipburn symptoms in Chinese cabbage [ Brassica Campestris L. ssp pekinensis ( Lour) Olsson. ] were studied. The tipburn symptoms was induced by de-ductting calcium from the nutrient solution. The results indicated that with the calcium content of leaves decreased the tipburn symptoms developed gradually and became visible finally. During the process photosynthetic rate decreased while sugar content and electrolyte leakage increased. Membranes was damaged and sap leaked out to leaf surface. The observation of ultrastructure showed that the plasmalemma invaginated, " small vesicles" emerged, then organelle disintegration started. Finally, soluble pectic content increased dramatically and cell wall crumbled. Solid remains could be seen in the cell cavities and intercellular space around the point of apearence of paper-like symptom. There was no correlation between blackened hydathodes and tipburn in Chinese cabbage.