水分胁迫下山杏根细胞显微结构变化的研究

ANATOMICAL DEVELOPMENT OF ROOT CELLS MICROSTRUCTURE IN RELATION TO WATER STRESS IN SIBERIAN APRICOT TREES

本实验采用3年生实生山杏苗,主要研究不同土壤水分胁迫下,新根内皮层细胞壁二次生长的phi-增厚、细胞核活性以及淀粉粒累积的显微特点及变化规律。实验中根据叶片的WSD水平将水分胁迫分为中度干旱及重度干旱。与对照材料相比,处于水分胁迫下的山杏新根内皮层所出现的phi-增厚现象比较明显,根尖分生组织细胞核活性减弱的同时淀粉粒积累显著增加。皮层细胞phi-增厚的发生可能是新根对于水分胁迫的保护性防御机能的体现。这些特征对于研究根对土壤水分条件的应答有着较为重要的作用。

The anatomical development of phi-thickening in the cortical tissue adjacent to the endodermis,degradation of nuclei and starch accumulation in the distal portion of roots in 3-year-old Siberian apricot seedlings were investigated in relation to water stress. The degree of water stress was shown by the water saturated deficiency（ WSD） of the leaves and was graded into three levels：unstressed,moderate stress,and severe stress plots. The roots under water stress,phi-thickening developed typically as compared with normal conditions. The development of phi-thickening in the cortex of Siberian apricot roots may be a defense mechanism against water stress. Water stress accelerated the degradation of nuclei and decreased starch accumulation in the distal portion of the roots. These features are important for understanding the response of the roots to soil water conditions.