干旱胁迫下不同甘蔗品种叶片解剖结构及生理生化的变化-植物学专业论文.docxVIP

II II 随着干旱胁迫的加剧，F172 叶绿体排列方向发生改变，基粒片层松散、不清晰， 但还可以看见完整的叶绿体形态；而 YL6 的叶绿体基粒片层更为松散、严重变形， 形态模糊。YL6 的叶绿体宽长比要远远大于 F172，因而 F172 的抗旱性亦大大强于 YL6。 3. 在干旱胁迫下四个甘蔗品种的叶片含水量、绿叶数、气孔导度、叶绿素含量 及比叶重等生理指标均呈现不同程度的下降。在重度干旱下，四个品种比较，抗旱 性强的品种 F172 和 GT21 的这些生理指标高于不抗旱的 YL6 和 YT93-159，复水后 的修复速度也高于不抗旱的甘蔗品种。 关键词：干旱胁迫；甘蔗；气孔；解剖结构；叶绿体 III III Leaf Anatomical Structure, Physiological and Biochemical Changes in Different Sugarcane Cultivars under Drought Stress ABSTRACT Sugarcane is a grassy crop grown in tropical and subtropical areas. Guangxi is the main sugarcane producer in China, and cane sugar industry is one of the most important economic pillars in Guangxi. Sugarcane growth duration is long, and the plants are tall and large, requiring large amount of water. Most of the sugarcane in Guangxi is grown in hilly, shallow tillage layer and rain-fed upland areas, therefore, sugarcane crop is seriously affected by drought that results in great economic losses. The present study employed strong drought resistant sugarcane cultivars F172 and GT21 and drought susceptible cultivars YT93-159 and YL6 as the plant materials, which were grown in pots. The plants were treated with varied degrees of drought stress: mild drought, 65%-70% of the soil water capacity; moderate drought, 45%-65% of the soil water content; severe drought, 25%-45% of soil water capacity and; control, 75% of soil water capacity. The changes of leaf stomata, anatomical structure and chloroplast ultrastructure of sugarcane in different drought stresses were analyzed using scanning electron microscopy, transmission electron microscopy and other techniques to investigate the cytological mechanism of drought resistance of sugarcane, and to provide the reference for screening drought resistant sugarcane cultivars. The main results were as follows. The results of leaf stomatal observation showed that the stomata were gradually closed, the length and width of stomatal apparatus were gradually getting smaller, and the stomatal density and stomat