摘要： 对染病和未感病鸭梨进行显微镜观察,并对酪氨酸酶、过氧化物酶、细胞色素氧化酶的活性,以及脯氨酸含量进行了生化分析.结果表明,梨黑心病不是由于菌类感染,而是属于生理病害.分析结果初步表明,鸭梨感黑心病后,呼吸代谢途径部分地由EMP—TCA径转变为HMP途径,而多酚类化合物的酶促褐变是产生黑心的直接结果.游离氧对这一转变起了促进作用.

关键词: 呼吸链, 末端氧化酶, 鸭梨黑心病, 发病机理

Abstract: The infected and normal Ya pear were inspected microscopically,and the activities of tyrosinase,peroxidase, cytochrome oxidase and the content of free proline were determined through the chemical analysis.The result indicated that the black kernel disease of Ya pears was not produced by bacteral infection but belonged to a physiologlcal disease. The results of biochemical analysis also indicated that the respiratory pathway of the infected fruits was partly changed from EMP-TCA pathway to HMP, and the brown cotor appeared under the action of polyphenol com pound enzyme seemed to result directly in black kernel. Free oxygen accelerated this process.

Key words: Respiratory chain, Terminal oxidase, Black kernel disease, Ya pear, Mechanism of disease