香根草对镉胁迫的光合响应  

Photosynthesis Response to Cadmium in Vetiveria Zizanioides(L.) Nash.

作　　者：高伟[1] 魏虹[1] 贾中民[1,2] 田晓峰 

机构地区：[1]三峡库区生态环境教育部重点实验室,西南大学生命科学学院,重庆400715 [2]重庆市地质矿产勘查开发局川东南地质大队,重庆400038 [3]广州广雅实验学校,广州510176

出　　处：《西南师范大学学报（自然科学版）》2012年第10期59-64,共6页Journal of Southwest China Normal University(Natural Science Edition)

基　　金：重庆市自然科学基金资助项目(CSTC2008BA7032)

摘　　要：以香根草当年实生分蘖苗为研究对象,研究了不同质量分数外源镉(0mg/kg,2mg/kg,20mg/kg和80mg/kg)对香根草生物量、色素质量分数、净光合速率和叶绿素荧光参数的影响.研究结果表明:①镉胁迫50d时,2mg/kg,20mg/kg和80mg/kg的镉处理对香根草的净光合速率Pn,ΦPSⅡ,ETR和qP均有促进作用,尤其是20mg/kg镉处理促进作用最强;但对生物量、光合素质量分数、Fv/Fm影响不大.②镉胁迫100d时,净光合速率Pn在镉质量分数为2mg/kg,20mg/kg时上升,80mg/kg时显著下降;ΦPSⅡ,ETR和qP均受到抑制,但只有在80mg/kg时显著下降.本研究表明香根草具有较高的镉耐性,可长时间适应低质量分数镉胁迫,甚至是短时间的高质量分数镉胁迫.Vetiveria zizanioides（L.）Nash are subjected to different kinds of Cadmium treatment（0 mg/kg,2 mg/kg,20 mg/kg and 80 mg/kg）,and their biomass,pigment content,net photosynthesis rate（Pn）and chlorophyll fluorescence parameters are investigated at 0d,50d and 100d.The results show in the following.①At 50 d,Cadmium conditions have facilitation on net photosynthetic rate（Pn）,PSⅡ photochemistry（ΦPSⅡ）,the electron transfer rate of PSⅡ（ETR） and photochemical quenching coefficient（qP） of Vetiveria zizanioides（L.）Nash especially under 20 mg/kg.Cadmium conditions could not effectively influence the biomass,photosynthetic pigment,the potential efficiency of primary conversion flight energy of PSⅡ（Fv/Fm） of Vetiveria zizanioides（L.）Nash.②At 100d,net photosynthetic rate（Pn） goes up significantly under 2 mg/kg and 20 mg/kg but decline significantly under 80 mg/kg,PSⅡ photochemistry（ΦPSⅡ）,the electron transfer rate of PSⅡ（ETR） and photochemical quenching coefficient（qP） all decrease but it drops significantly only under 80 mg/kg.The above results prove that Vetiveria zizanioides（L.）Nash could not only tolerate Cadmium stresses with low concentration for a long time,but also endure Cadmium stresses with high concentration for a short time.

关 键 词：镉胁迫 香根草 光合作用 叶绿素荧光 

分 类 号：Q949.714.2[生物学—植物学]