水分胁迫下两种抗旱类型狗牙根种质的生理生态响应差异

摘要

为探讨狗牙根对干旱胁迫的响应规律及其差异,对不同水分胁迫(土壤相对含水量分别为70 %~75 %、50 %~55 %、30 %~35 %、10 %~15%)下抗旱(Cd047,Cd016)和不抗旱(Cd013,Cd034)狗牙根种质的株高、生物量、渗透调节物质、绿叶率、叶绿素 SPAD值、光化学效率及相对电导率进行了测定.结果表明,随水分胁迫增加,狗牙根叶片相对电导率呈上升趋势,可溶性糖、脯氨酸含量呈先升后降趋势,而株高、生物量、叶片绿叶率、光化学效率及叶绿素 SPAD均呈下降趋势.与不抗旱狗牙根比,水分胁迫后抗旱狗牙根叶片相对电导率增加缓慢,脯氨酸和可溶性糖含量积累速度快,株高、生物量、绿叶率、SPAD值、光化学效率降低幅度小,其中可溶性糖含量增加,叶绿素含量及光化学效率的维持可能是狗牙根抗旱性强的原因之一.%In order to discuss the response mechanism and difference of Cynodon dactylon to drought stress,the height,biomass,osmotic adj ustment substance,green leaf percentage,chlorophyll SPAD, photochemical efficiency and relative conductivity of drought-resistant germplasm(Cd047 and Cd016)and non-drought germplasm(Cd013 and Cd034)of C.dactylon under different water stress (the soil relative water content was respectively 70% ~75%,50% ~55%,30% ~35%,10% ~15%)were measured. The results showed that with the increasing of water stress,the leaves relative conductivity of C.dactylon showed an increasing trend,the content of proline and soluble sugar increased first then decreased,and the height,biomass,green leaf percentage,chlorophyll SPAD and photochemical efficiency showed a decrea-sing trend.Compared with non-drought materials,the increasing degree of leaves relative conductivity for drought C.dactylon increased slowly,the accumulating proline and soluble sugar content were high,and the decreasing degree of height,green leaf percentage,biomass,SPAD and photochemical efficiency was little.The increasing soluble sugar content and maintaining of chlorophyll content and photochemical effi-ciency may be one of the reasons that C.dactylon had high drought resistance.