摘要
利用CIRAS-2型便携式光合作用仪测定不同土壤水分下3年生小叶扶芳藤（Euonymus fortuneivar.radi-cansSieb.）叶片净光合速率（Pn）、蒸腾速率（Tr）、水分利用效率（WUE）及光能利用效率（LUE）等生理参数,阐明其光合生理参数对土壤水分和光照强度的响应规律,探讨小叶扶芳藤正常生长发育所需的土壤水分和光照条件.结果表明：小叶扶芳藤的Pn、Tr、WUE及LUE对土壤水分和光照强度的变化具有明显的阈值.（1）采用非直角双曲线模型进行模拟光响应过程较好,在土壤相对含水量（RWC）为72.2%和32.3%时,曲角（K）值较小;在其它水分条件下,K值接近于1.随着土壤水分（RWC为22.4%-72.2%）的递增,光补偿点降低,光饱和点、最大净光合速率及表观量子效率均呈现升高趋势,在RWC为72.2%时,光补偿点最低（22.6μmol·m^-2·s^-1）,光饱和点最高（1 400μmol·m^-2·s^-1）.（2）维持小叶扶芳藤正常生长（同时具有较高Pn、LUE及WUE）的土壤水分范围,在RWC为44.2%-72.2%之间,最佳土壤水分在RWC为72.2%左右,正常生长所允许的最低土壤水分在RWC为32.3%左右.（3）小叶扶芳藤对光照环境的适应性较强,在光合有效辐射强度为600-1 600μmol·m^-2·s^-1范围内,Pn和WUE都具有较高水平,饱和光强大约在800-1 400μmol·m^-2·s^-1之间,LUE在100-300μmol·m^-2·s^-1光强范围内达到峰值.
In order to ascertain the optimum soil moisture and light intensity for the growth of Euonyrnus fortunei var. radicans, we measured the light response of photosynthetic physiology parameters, such as net photosynthetic rate （Pn）,transpiration rate （Tr）, water use efficiency （WUE） and light use efficiency （LUE）, to three-year-old leaf of E. fortunei var. radicans in different soil moisture with CIRAS-2 portable photosynthesis system. The results showed that the Pn, Tr, WUE and LUE of leaf has notable threshold value to the variation of soil moisture and photosynthetically active radiation（PAR）. （1）The non-rectangular hyperbola model is very good to simulate light-response curve,when relative water content （RWC） is 72.2% and 32.3% ,the con-vexify is little,and in other soil moisutre,the convexity is about 1. With the increase of soil moisture （RWC is about 22.4%-72.2%）,the number of light compensation point is decline while light saturation point, the maximum Pn and apparent quantity yield are all increasing. When RWC is about 72.2% ,the light compensation point is at the minimum of 22.6 μmol·m^-2·s^-1,and light saturation point is at the maximum of 1 400 μmol·m^-2·s^-1. （2）In order to maintain the high-level Pn, LUE and WUE synchronously, the fitting RWC is about 44.2%-72.2% ,and the optimum RWC is 72.2%. The most deficient degree to RWC is 32.3% for the normal growth of E. fortunei var. radicans. （3）The adaptability of E. fortunei var. radicans to light conditions is very fargoing,and the high-level Pn and WUE is appeared in the PAR of 600- 1 600 μmol·m^-2·s^-1 ,and the light saturation points of Pn and WUE are all about 800-1 400 μmol·m^-2·s^-1. The peak value of LUE appears at the PAR of 100-300 μmol·m^-2·s^-1.
出处
《西北植物学报》
CAS
CSCD
北大核心
2007年第12期2514-2521,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家十一五"科技攻关子课题(2006BAD03A1205)
山东省农业良种产业化工程项目
关键词
小叶扶芳藤
光合有效辐射
净光合速率
蒸腾速率
水分利用效率
土壤水分
Euonyrnus fortunei var. radicans
photosynthetically active radiation
net photosynthetic rate
transpiration rate
water use efficiency
soil moisture
