【摘要】 以长期继代培养的楸树愈伤组织和新诱导的楸树愈伤组织为试验材料，利用石蜡切片比较分析它们的组织形态特征，并测定过氧化物酶(POD)、超氧化物歧化酶(SOD)和淀粉酶的活性，以及可溶性蛋白与可溶性糖的含量，以探究楸树愈伤组织长期继代培养后分化再生困难的形成原因。组织形态学观察分析发现，继代培养7 a的白色颗粒状愈伤组织细胞中淀粉粒含量丰富，分布均匀，仍为胚性愈伤组织；新诱导的浅绿色愈伤组织存在明显的细胞分化中心，有均匀分布的淀粉粒，为早期胚性愈伤组织；新诱导的黄白色致密愈伤组织为非胚性向胚性转化的愈伤组织，新诱导黄白色疏松愈伤组织为非胚性愈伤组织。生理生化指标测定分析发现，继代培养7 a的楸树胚性愈伤组织中可溶性糖和可溶性蛋白的含量均显著高于新诱导出的3种愈伤组织，但其同工酶活性却较低，表明在长期继代培养的过程中，楸树愈伤组织的生理生化代谢活性降低。由此推测生理生化代谢活性的下降可能是造成楸树胚性愈伤组织长期继代培养后分化再生困难的重要因素。更多还原

【Abstract】 In this study, the calli of Catalpa bungei subcultured for a long time and the newly induced calli of Catalpa bungei were used as experimental materials, the differences in their histological characteristics were compared and analyzed by paraffin sections, and the differences in the activities of peroxidase(POD),superoxide dismutase(SOD) and amylase, the changes in the content of soluble protein and soluble sugar were determined, so as to explore the reasons for the formation of difficulty in differentiation of regeneration of Catalpa bungei callus after long-term subculture. The observation and analysis of histomorphology showed that the white granular callus cells subcultured for 7 years were still embryogenic callus with abundant starch grains and uniform distribution; the newly induced light green calli had obvious cell differentiation centers and uniformly distributed starch grains. They were early embryogenic calli. The newly induced yellow white compact calli were non embryogenic to embryogenic calli. The newly induced yellow white loose calli were non embryogenic calli. The determination and analysis of physiological and biochemical indexes showed that the contents of soluble sugar and soluble protein in the embryonic callus of Catalpa bungei subcultured for 7 years were significantly higher than those in the three kinds of newly induced callus, but their isozyme activities were low, indicating that the physiological and biochemical metabolic activities of Catalpa bungei callus decreased in the long-term subculture process. It is speculated that the decline of physiological and biochemical metabolic activity may be an important factor that causes the difficulty in differentiation and regeneration of embryonic callus of Catalpa bungei after long-term subculture.更多还原