摘要
设置0、50、100、200、500、800、1100、1400、1700、2000μmol/m^2·s等10个内置光源光照强度,测定不同位叶对光照强度的响应能力,分析自然光下不同位叶的光合贡献率与水分消耗率差异,结果表明:老芒麦能利用≥50μmol/m^2·s光照进行光合作用;叶片光合参数极显著受光照强度和叶位的影响(P<0.01),光照强度主要影响光合速率,叶位主要影响气孔导度;不同位叶的净光合速率、气孔导度、胞间CO_2浓度、蒸腾速率在500~1700μmol/m^2·s光照下均无显著差异;水分利用效率在光照500~800μmol/m^2·s时最高;在自然光下,不同位叶单位叶面积的光合速率有显著差异(P<0.05),第1叶单叶光合速率和光合贡献率最大且水分利用效率最高。因此,田间管理时应注意保持第1~3叶的完整与健康,以保证老芒麦种子发育对营养的需求。
In the present study,the Elymus sibiricus leaves in different position at filling stage were irradiated with ten built-in light intensity(0,50,100,200,500,800,1100,1400,1700,2000μmol/m^2·s).Some parameters,such as photosynthetic rate,transpiration rate,stomatal conductance,photosynthetic contribution rate,water consumption rate of leaves in different position,were measured.The following results were observed.1)E.sibiricus could use the light intensity higher than 50μmol/m^2·s for photosynthesis.Leaf photosynthetic parameters existed highly significant difference in different light intensity and leaf position(P〈0.01).While light intensity mainly affected photosynthesis rate,and leaf position mainly affected stomatal conductance.2)To the E.sibiricus leaves in different position,the net photosynthetic rate,stomatal conductance,intercellular CO_2 concentration,transpiration rate all were not significantly different under the condition of 500~1700μmol/m^2·s illumination.And water use efficiency reached the highest in the condition of 500~800μmol/m^2·s illumination.3)In the condition of natural light,the photosynthetic rate per unit leaf area were significantly different between the leaves in different position(P〈0.05).And the photosynthetic rate,contribution rate and water use efficiency in the first leaf all were the maximal.Therefore,field management should pay attention to maintaining the integrity and health of the first leaf,in order to obtain adequate nutrition for seed development of E.sibiricus.
出处
《中国草地学报》
CSCD
北大核心
2015年第6期49-55,共7页
Chinese Journal of Grassland
基金
四川省科技厅应用基础项目(2012JY0062)
四川省科技支撑计划(2011NZ0064)资助
关键词
老芒麦
光照强度
光合作用
叶位
水分利用效率
Elymus sibiricus
Light intensity
Photosynthesis
Leaf position
Water use efficiency