春季高寒草地牧草根中营养物质含量和保护酶活性的变化及其生态适应性研究

本文研究了高寒草地３种立地条件下垂穗披碱草（Ｃｌｉｎｅｌｙｍｕｓｎｕｔａｎｓ）在春季萌动过程中根系碳水化合物和保护酶活性的变化，结果表明：（１）入冬时根系中碳水化合物贮量高、保护酶活性强的牧草春季萌动早、生长快、抗寒性较强。（２）当春季气温波动式回升时，牧草根系中可溶性糖含量、ＳＯＤ（超氧化物歧化酶）和ＰＯＤ（过氧化物酶）活性随气温上升而下降，随气温下降而上升。其中火烧地牧草根中ＳＯＤ和ＰＯＤ酶活性一直保持较高水平，并对温度变化反应敏感，而抗寒性也较强。因此春季高寒山区牧草根内的代谢改组（增加可溶性糖）和酶系统的调节（增加ＳＯＤ、ＰＯＤ活性）是其对生态环境适应的重要生理反应。

THE CHANGE IN CARBOHYDRATE CONTENT AND PROTECTING ENZYME ACTIVITIES IN ROOT OF ALPINE FORAGE RELATED TO ITS ADAPTATION TO COLD IN SPRING

The experiments were conducted to study changes in content of Carbohydrate and activities of protecting enzyme in root of Clinelymus nutans planted in differently treated soils during the germination in spring; The results showed:(1) The more the forage's root kept Carbohydrate the higher the activities of protecting enzyme were in winter,the earlier it ger-minated and the more hardy it was in spring.(2) The contents of soluble sugar an activities of SOD, POD in root of Alpine forages were reduced with increasing of temperature and raised with decreasing of temperature. The forage planted in fired soil was more resistant to coldness because high level of SOD and POD activities in root were keeped and quickly increased by temperature drop. So change in Carbohydrate metabolism and adjustment of enzyme system were an important physiological re- sponses of forage to ecological environment.