水分胁迫对3个枣品种光合特性及水分利用率的影响

摘要

对朝阳地区常见的3个品种枣苗(大平顶枣、金铃圆枣、三星大枣)2年生嫁接苗进行4个不同的土壤控水处理,测定出3个品种枣苗在不同水分胁迫条件下的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)等光合特性指标,并计算水分利用效率,以探讨水分胁迫对3个枣品种光合特性及水分利用率的影响,结果表明：土壤水分的变化与净光合速率和气孔导度的变化呈正比关系；在重度胁迫条件下,随着胁迫时间的增加,3个枣品种胞间CO2浓度值接近直线上升状态；随干旱胁迫强度加大,蒸腾速率呈下降趋势。三个枣品种抗旱性大小顺序为三星大枣>金铃圆枣>大平顶枣。%Two-year-old Zizyphus jujuba ‘Dapingding’,Zizyphus jujuba ‘Jinlingyuan’and Zizyphus jujube‘Sanxingda’in Chaoyang Region were conducted water-controlled treatment.Photosynthetic rate under (Pn),tran-spiration rate (Tr),stomatal conductance (Gs),intercellular CO2 concentration (Ci)of three varieties were meas-ured under different water stress conditions.Water use efficiency was calculated.Effects of water stress on photo-synthetic characteristics and water use efficiency of three j uj ube varieties were discussed.Result shows that:changes of soil moisture with net photosynthetic rate and stomatal conductance appear direct proportional relationship;under severe stress,intercellular CO2 concentration values among three jujube varieties are close to straight up state with the increase of stress time ;as drought stress intensity increased,transpiration rate decreased.The descending or-der of drought resistance for three varieties of Zizyphusjujuba is Zizyphusjujube ‘Sanxingda’>Zizyphusjujuba‘Jinlingyuan’> Zizyphus jujuba ‘Dapingding’.