大叶冬青对低温胁迫的生理响应及抗寒性分析

Physiological Responses of Ilex latifolia to Low Temperatrure and Its Cold Tolerance

通过对不同低温处理下大叶冬青Ilex latifolia叶片内过氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)等保护酶活性、叶绿素(Chl)总量、渗透调节物质可溶性糖(SS)、细胞膜脂质过氧化产物丙二醛(MDA)含量以及相对电导率的测定,探讨大叶冬青对不同低温胁迫的响应特性和耐寒适应能力.结果表明:随着胁迫时间的延长,不同低温处理中叶片相对电导率均呈先升后降又升的变化,且半致死温度(LT50)均在-11℃左右;叶绿素总量在0和-6℃胁迫下先降后略有上升,而-12和-18℃处理中则呈一直下降的变化;SOD和CAT活性及SS含量均呈先升后降的变化,且均以0和-6℃处理中上升较为明显;POD活性呈先降后升的变化,以0和-6℃处理上升明显,而以-12和-18℃处理下降显著;MDA含量整体呈上升变化,但24 h内以-18℃处理的上升最为明显.

The relative electric conductivity（REC）,semilethal temperature（LT50） of Ilex latifolia under low temperature below 0 ℃,and SOD,POD,CAT activity,content of MDA,soluble suger and chlorophyll were investigated.The results showed that as low temperature stress intensified and time prolonged,the REC increased at the beginning then decreased,but increased at last.The LT50 was-11 ℃ or much lower;The content of chlorophyll decreased at the beginning then increased in 0 and-6 ℃ treatment,but decreased at all in-12 and-18 ℃ treatment;The content of soluble sugar and SOD and CAT activities increased at the beginning then decreased,the greatest changes in 0 and-6 ℃ treatment;POD activity decreased at the beginning then increased;The content of MDA decreased at all,but greatest changes was found in 18 ℃ treatment within 24 h.