发菜光合特性与水分关系的研究

A correlation research between photosynthetic characteristics and moisture of Nostoc flagelliforme

处于自然光照与室内散射光照和2种不同供水时间 8∶00与20∶00 条件下的发菜藻殖段,用Li-6200光合仪作其光合速率日变化测试,结果得出:自然光照与室内散射光照及2种供水时间对发菜光合速率、蒸腾速率、温度、水汽压亏缺等因子之间的影响关系.自然光照条件下,对发菜20∶00供水,在次日的发菜光合速率日变化中,光合速率与水汽压亏缺呈显著性正相关关系 r=0.6216 .发菜光合速率日变化曲线与水汽压亏缺日变化曲线趋于一致,当光照强度为1324μmol·m-2·s-1时,水汽压亏缺达到44.5mb,发菜光合速率日变化出现峰值 1.68mg·g-1·s-1 .对发菜8∶00供水,其光合速率日变化在供水5h后出现峰值;在室内散射光照条件下,在8∶00和20∶00供水都使发菜在光合速率日变化中,保持了较高的相对含水量,光合速率降低,并处于较长时间的呼吸作用状态.

Under the conditions of sunlight and diffused light two different moisture contents of hormogonia of Nostoc Flagelliforme are tested at 8∶00 and 20∶00 by Li6200 Photosynthesis Meter.It researched correlation among the factors of Pn,TRAN,Qn,TAIR,VPD.The results are:when water is supplied to Nostoc flagelliforme at 20∶00 under the sunlight condition,the Pn and VPD show obvious positive correlation (r=0.6216) on the second day,photosynthetic and VPD diurnal changes tend to the similar degree,accordingly,when Qn=1 324 μmol·m-2·s-1 and VPD=44.5 mb in the same condition,Pn appears diurnal change maximum (1.68 mg·g-1·s-1);when moisture is supplied to Nostoc flagelliforme at 8∶00,Pn and TRAN shows positive correlation,Pn reaches the peak value after 5 hours of moisture supply,also TRAN appears peak value late.No matter when moisture is supplied at 8∶00 and 20∶00 under a weaker diffused light,Nostoc flagelliforme keeps a higher water content,and it shows respiratory condition for a long time.