羊草在多云条件下光合及水分生理生态特征研究  

Characteristics of Photosynthesis and Water Physio-ecology of Leymus chinensis in Cloudy Conditions

作　　者：郝广 齐志敏[1] 梁颖[1] 闫勇智 李阳[1] 王玮琛[1] 宋长清 杨九艳[1] 

机构地区：[1]内蒙古大学生命科学学院,呼和浩特010021 [2]内蒙古赤峰市元宝山区五家镇经济综合服务中心,内蒙古赤峰024087

出　　处：《内蒙古大学学报（自然科学版）》2016年第5期515-521,共7页Journal of Inner Mongolia University：Natural Science Edition

基　　金：内蒙古自然科学基金重大项目(2014ZD02);内蒙古大学校级大学生创新创业训练计划项目(201514212)

摘　　要：使用Li-6400便携式光合测定仪,对自然条件下呼伦贝尔草原羊草的光合及水分生理生态特征进行了研究,结果表明:八月的呼伦贝尔草原多阴云天气,羊草的净光合速率日变化呈现双峰曲线,蒸腾速率曲线与净光合速率表现出一致的趋势.光响应曲线、CO_2响应曲线结果表明:光合速率(P_n)与CO_2浓度(C_(CO_2))之间回归方程为P_n=-0.09051+0.03865 C_(CO_2)-1×10^(-5) C_(CO_2)~2,根据回归方程可求得CO_2补偿点为2.34μmol·m^(-2)·s^(-1),CO_2饱和点为1932.5μmol·m^(-2)·s^(-1).P_n与光合有效辐射(PAR)之间回归方程为P_n=-2.0596+0.02094 PAR-8×10^(-6) PAR2,光补偿点(LCP)为102.36μmol·m^(-2)·s^(-1),光饱和点(LSP)为1308.75μmol·m^(-2)·s^(-1),羊草较高的光补偿点和光饱和点是其适应内蒙古高原高光强环境的表现,也是其成为该地区优势植物的适应对策.Photosynthesis and water physio-ecology of Leymus chinensis were characterized un- der the natural condition, using Li-6400 portable photosynthetic system. The results were as follows： 1）The weather condition of Hulunbuir grassland was mainly cloudy in August. The net photosynthetic rate （Pn） of Leymus chinensis was a bimodal curve and the transpiration rate （Tr） had a similar pattern as Pn ＇s. 2）According to the photoresponse curve and the CO2-response curve,the regressive equation of Pn and CCO2 was Pn =- 0. 09051＋0. 03865 CCO2- 1×10^-5 CCO2^2. Thus, the Co2 compensation point was 2.34μmol·m^-2·s^-1 and the CO2 saturation point was 1932.5μmol·m^-2·s^-1, 3） The regressive equation of Pn and photosynthesis active radiation （PAR） was Pn = -2. 0596＋0. 02094 PAR-8×10^-6 PAR2.Thelight compensation point was 102.36μmol·m^-2·s^-1 and the light saturation point was 1308.75μmol·m^-2·s^-1. A higher level of light compensation point and light saturation point of Leymus chinensis may attribute to a long adaption to the high light environment of Inner Mongolian Plateau, which make it be the dominant plant of this region.

关 键 词：羊草 净光合效率 蒸腾速率 水分利用效率 

分 类 号：Q948[生物学—植物学]