水分胁迫对豇豆幼苗光合特性的影响

Effect of Water Stress on Photosynthetic Characteristics of Cowpea Seedlings

对四叶一心期的豇豆幼苗进行水分胁迫处理,研究其光合特性的变化。结果表明:随着胁迫时间的延长,土壤含水量、豇豆幼苗叶片含水量出现持续下降;气孔张开率、气孔导度、叶绿素含量出现持续下降趋势,到胁迫8d后均与对照出现极显著差异;豇豆幼苗叶片胞间CO2浓度表现为为基本稳定、突然下降、再持续升高的趋势,胁迫8d后为极显著差异;光合速率、蒸腾速率随胁迫时间延长出现持续下降趋势,蒸腾速率从胁迫4d与对照出现显著差异,从6d时开始出现极显著差异;光合速率则从6d开始出现显著差异,从8d开始出现极显著差异;光合速率与气孔张开率、气孔导度、叶片叶绿素含量成正相关,且与气孔张开率、气孔导度呈显著正相关;与胞间CO2浓度呈负相关。从相关性分析可以看出,气孔因素是影响光合速率的主要因素。豇豆幼苗忍耐自然水分胁迫时间为8d。

The cowpea seedlings were treated when they had four leaves and a heart by water stress.The results showed that the soil water content and leaves water content continued to decrease,the stomata opening rate and stomata conductance continued to decrease too,and they were different from not treated significantly when stressed 8days later,the chlorophyll content decreased and was different from not treatment significantly when stressed 8days later,the intercellular CO 2 concentration firstly was stable,then decreased,finally continued to increase,and was different from not treated significantly when stressed 8days later,the transpiration rate and photosynthetic rate decreased continuously,the transpiration rate had remarkable difference from not treated when has been stressed for 4days,while significant difference when has been stressed for 6days,the photosynthetic rate had remarkable difference from not treated when has been stressed for 6days,while significant difference when has been stressed for 8days.The photosynthetic rate was positively related to stomata opening rate,stomata conductance and chlorophyll content,while was negatively related to intercellular CO 2 concentration.It was concluded that stomata factor was the main factor effecting photosynthetic rate.The cowpea seedlings can endure water stressing for 8days.