油菜叶片气体交换对O_3浓度和熏蒸方式的响应  

Response of gas exchange of rape to ozone concentration and exposure regimes

作　　者：冯兆忠[1] 王效科[1] 郑启伟[1] 冯宗炜[1] 谢居清[2] 陈展[1] 

机构地区：[1]中国科学院生态环境研究中心系统生态国家重点实验室,北京100085 [2]西北农林科技大学农学院农学系,杨凌712100

出　　处：《生态学报》2006年第3期823-829,共7页Acta Ecologica Sinica

基　　金：国家重点基础研究发展规划资助项目(2002CB410803)~~

摘　　要：运用CIRAS-1型便携式光合作用测定系统,在田间原位比较研究了不同O3浓度(CF,50 nl.L-1和100 nl.L-1)和熏蒸方式(恒定和动态)油菜叶片的气体交换特征及其对光强、CO2浓度升高的响应。结果表明(1)恒定熏气下,O3浓度增加导致叶片的蒸腾速率降低,水分利用效率提高,但动态熏蒸则引起蒸腾速率增加,水分利用效率下降,而且明显导致光合速率和气孔导度的降低;(2)高浓度的O3(100 nl.L-1)引起叶片的表观量子产额、暗呼吸饱和光强和最大净光合速率显著降低,光呼吸和CO2补偿点显著升高;熏蒸方式对叶片的暗呼吸、光补偿点、饱和光强、最大光合速率、羧化效率的影响差异显著;(3)不论何种熏蒸方式,高浓度的O3都引起下叶位的Fv/Fo、Fv/Fm显著降低,对上叶位没有影响。相同剂量下,动态熏蒸对叶片气体交换的影响更大,不利于植物生长和干物质的积累。Ozone is the most important phytotoxic gaseous pollutant in many parts of the world. The study reported was conducted to elucidate the response of gas exchange characteristics of rape （ Brassica napus L. ） to different O3 concentrations, and fumigation regimes under equal ozone dose at a site on the Yangtze River Delta, China. Rape seeds were germinated in seedbeds on 20 October, 2004. The seedlings were directly transplanted into twelve 2m×2m plots on 18 November 2004. After it became warm and the rape turned green, twelve open top chambers （OTCs） were erected on 21 March 2005（tbe chamber was octagon, 2.2 m high and 2 m in diameter）, where the plants were exposed to O3 from 23 March 2005. Over the course of the fumigation, three OTCs were ventilated continuously （8h d^-1 ） with passing air through activated charcoal filter （ CF, O3 range ： 5-15 nl· L^-1）, three received 50 nl· L^-1 O3 （50, 03 range ： 45-55 nl· L^-1） and three received 100 nl· L^-1 O3 （ 100, O3 range： 90-110nl· L^-1）, which were ventilated continuously （8h d^-1） with constant O3 concentration, respectively. The other three were exposed to another O3 regime （9：00-11：00：50nl· L^-1, 11：00- 13：00：100nl· L^-1, 13：00- 15：00：200nl· L^-1, 15：00-17：00：50nl· L^-1）, although the exposure dose was the same as the third treatment. The additional ozone was carried out from 9 ： 00 to 17 ： 00 per day, and suspended when it rained. Each treatment was randomly arranged in field. Ozone was generated using pure compressed air by electric discharge （ozone generator, QHG-1, Yuyao, China） and mixed with charcoal filtered ambient air by means of flow controllers linked to a desktop computer, programmed with individual exposure profiles. To guarantee controlled and reproducible exposure conditions, ozone concentrations were measured continuously within each chamber at plant height on a 5 min interval by an ozone analyst （Monitor Labs Inc. ML9810B）. After 25 days＇ exposure to 03 ,

关 键 词：臭氧 油菜 光合特性 羧化效率 表观量子产额 叶绿素荧光参数 

分 类 号：X173[环境科学与工程—环境科学]