水分胁迫对糜子植株苗期生长和光合特性的影响  

Effect of Water Stress on Seedling Growth and Photosynthetic Characteristics in Broomcorn Millet

作　　者：冯晓敏[1] 张永清[1,2] 

机构地区：[1]山西师范大学生命科学学院,山西临汾041004 [2]山西师范大学城市与环境科学学院,山西临汾041004

出　　处：《作物学报》2012年第8期1513-1521,共9页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(30871483);山西省自然科学基金项目(2006011086)资助

摘　　要：选取耐旱性不同的糜子品种陇糜4号(强抗旱)、晋黍7号(旱敏感)和5283黄(中等抗旱),采用盆栽控水试验,调查不同水分处理对糜子苗期主要性状和光合参数的影响。结果表明:(1)水分胁迫下各品种的株高、叶面积、根重、叶绿素含量、根系活力均呈下降趋势,且陇糜4号的降幅小于5283黄和晋黍7号。(2)水分胁迫下,3个品种的固定荧光值(Fo)和非光化学猝灭系数值(qN)均显著增加,在重度胁迫后,陇糜4号、5283黄和晋黍7号的Fo值分别比对照增加24.6%﹑34%和40.8%,qN值分别增加0.956、1.083和2.183,且表现为旱敏感品种晋黍7号的增加幅度大于强抗旱品种陇糜4号;各品种的可变荧光(Fv)、最大荧光(Fm)、最大光化学量子产量(Fv/Fm)、PSII的潜在活性(Fv/Fo)、光化学猝灭系数(qP)值均因水分胁迫而降低。在中度和重度胁迫时,与正常灌水相比差异达显著水平,降幅以晋黍7号>5283黄>陇糜4号。(3)各品种的净光合速率、蒸腾速率、气孔导度及胞间CO2浓度均因水分胁迫而下降,强抗旱品种陇糜4号各值的变化幅度均小于中等抗旱品种5283黄和旱敏感品种晋黍7号,表明陇糜4号的光合参数受水分胁迫的影响最小,较高的电子传递速率和较强的光能转化能力是陇糜4号适应干旱环境的重要生理特性。(4)水分胁迫导致糜子叶片对强光的敏感性增加,干旱和光抑制对光系统II造成的叠加伤害随干旱加重和品种抗旱性减弱而加剧,因此,对强光下的糜子幼苗应及时补水,以避免干旱和高光强的叠加伤害。The response of main growth characteristics and photosynthetic parameters in seedlings of broomcorn millets cultivars Longmi 4（drought resistant）,Jinshu 7（drought-sensitive） and 5283 Huang（medium drought resistant） to three different drought stresses and normal irrigation were studied in a pot experiment.The result showed that drought stress decreased plant height,leaf area,root weight,chlorophyll content,and root activity.In addition the decreased range of Jinshu 7 was bigger than that of Longmi 4 and 5283 Huang.With the increasing of drought stress,fixation fluorescence value（Fo） and non photochemical quenching coefficient（qN） increased significantly,in Longmi 4,5283 Huang,and Jinshu 7,Fo was increased by 24.6%,34.0%,and 40.8%;qN was increased by 0.956,1.083,and 2.183,however,Fv,Fm,Fv/Fm,Fv/Fo,and qP all were decreased with the significant differences from those in the control under moderate stress and serious stress.Water stress decreased photosynthetic rate,transpiration rate,stomatal conductance,and intercellular CO2 concentration,which were lower in Longmi 4 than in Jinshu 7 and 5283 Huang,indicating that higher photosynthetic efficiency,stronger light energy transfer capacity and greater relative growth rate in Longmi 4 may be the major physiological traits adapted to drought stress.Sensitivity of broomcorn millet leaves to light increased under water stress,making double injury of drought and photo inhibition to photosystem II with severer drought and weak drought resistance.Therefore,we should water the broomcorn millet seedlings to avoid the injury of severe drought and high light.

关 键 词：糜子 水分胁迫 光响应 叶绿素荧光参数 

分 类 号：S516[农业科学—作物学]