不同水分处理对地黄光合特性的影响

Effect of different moisture treatments on photosynthetic characteristics of Rehmannia glutinosa Libosch

【目的】研究不同水分处理对地黄光合生理特性的影响,为其生长期间的水分管理提供理论依据。【方法】以地黄品种‘北京1号’为供试材料,采用盆栽试验研究不同水分胁迫下（处理Ⅰ~Ⅲ土壤含水量分别为田间持水量的65%,50%和35%）地黄叶片光合特性及叶绿素含量的变化。【结果】在地黄苗期、花期及根系膨大期,随着光合有效辐射的增加,3个水分处理的净光合速率呈增加趋势;处理Ⅰ和处理Ⅱ的光饱和点均在1600μmol/（m^2·s）左右,处理Ⅲ的光饱和点在1400μmol/（m^2·s）左右;随着地黄生育进程（苗期-花期-根系膨大期）的推进,3个水分处理地黄的净光合速率、气孔导度、胞间CO2浓度、蒸腾速率及叶绿素含量逐渐增加,且处理Ⅰ＞处理Ⅱ＞处理Ⅲ。【结论】地黄苗期土壤含水量维持在田间持水量的50%,花期及根系膨大期维持在田间持水量的65%,是最适宜地黄叶片进行光合作用的水分管理措施。

【Objective】 Study on the photosynthetic characteristics of Rehmannia glutinosa Libosch was done under different moisture treatments to provide theoretical basis for their water supply during growing.【Method】 Beijing No.1 as experiments material,the changes of photosynthetic characteristics and chlorophyll content in R.glutinosa Libosch under manmade conditions（the treatments of soil moisture Ⅰ-Ⅲ were 65%,50% and 35% of field capacity） were studied.【Result】 The results were as follows：the net photosynthetic rate of three moisture treatments increased with the increase of photosynthetically active radiation during the seedling, anthesis and root enlargement stage. Under treatment Ⅰ and treatment Ⅱ , light compensation point of the R. glutinosa Libosch was about 1 600 tzmol/（m^2 · s）,while under treatment Ⅲ ,light compensation point of the R. glutinosa Liboseh was about 1 400 μmol/（m^2 · s）. With the growing, the net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate and chlorophyll content increased obviously. The sequence from the hightest to the lowest was treatment Ⅰ〉 treatmentⅡ 〉treatment Ⅲ. [Conclusion] Keeping the soil moisture to 50% of field capacity during the seeding period but 65% during the flowering period and storage root thickening period is the best irrigation arrangement for the leaves of R. glutinosa Libosch to make photosynthesis.