高温胁迫对蝴蝶兰幼苗形态和生理特性的影响

在40℃/30℃(d/n)高温条件下分别进行0d、2d、4d、6d 的处理，观察了蝴蝶兰幼苗的形态变化，研究了蝴蝶兰兰幼苗叶片某些生理生化指标的变化。结果表明，随胁迫时间的延长，超氧阴离子自由基(O2-.)产生速率加快，丙二醛（MDA）含量增加，细胞膜脂过氧化作用明显加强；可溶性糖含量、脯氨酸含量逐渐增加；高温胁迫2d，可溶性蛋白质含量、超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性迅速上升，但相对电导率的增加并不大，叶绿素含量的下降也较小，与对照处理的相比差异不显著，说明蝴蝶兰幼苗可通过增加可溶性蛋白、可溶性糖、脯氨酸含量以及SOD、POD、CAT活性来提高其耐热性。之后可溶性蛋白含量、叶绿素含量以及SOD、POD、CAT活性显著下降，相对电导率急剧上升。

Effect of High Temperature Stress on Morphological and Physiological Characteristics in Leaves of Phalaenopsis Seedlings

Abstract: Phalaenopsis seedlings were treated with the temperature of 40℃(day)/30℃(night) for 0,2,4,6 day respectively,the morphological characteristics and several related physiological indexes in leaves of Phalaenopsis seedlings were determined.The results showed that generation rate of the superoxide free radical(O2-.),the contents of malondialdehyde (MDA),soluble sugar and free prolin were gradually increased with prolonging stress time;During the early 2 day of treatment,soluble protein content ,SOD,POD,CAT activities increased dramatically ,but relative electrical conductivity and chlorophyll content increased slightly.There were no significant difference for relative electrical conductivity and chlorophyll content between during 2 day of treatment and control.The results indicated that the heat tolerance of Phalaenopsis seedlings was improved by enhancing the contents of soluble protein,soluble sugar,free prolin and activities of SOD,POD,CAT.Then the contents of soluble protein,chlorophyll,the activities of SOD,POD and CAT decreased significantly, relative electrical conductivity ascended sharply.