水分胁迫对沙地樟子松和紫穗槐生理特性的影响

Effect of Water Stress on Physiological Characteristics of Sand Pinus sylvestris var.mongolica and Amorpha fruticosa

采用盆栽控水试验,对沙地樟子松、紫穗槐苗木在不同水分条件下叶水势、叶绿素、脯氨酸、丙二醛(MDA)和相对电导率等生理指标进行测定。结果表明:随着水分胁迫的加剧,樟子松和紫穗槐水势均呈递减的趋势。樟子松在轻度水分胁迫(土壤含水量为田间最大持水量的65%)时,叶绿素a、叶绿素b和叶绿素总量有所升高,而后又逐渐下降;严重水分胁迫(土壤含水量为田间最大持水量的35%)时,叶绿素a、叶绿素b、叶绿素总量分别为0.50、0.16、0.66 mg·g-1。紫穗槐叶绿素a、叶绿素b和叶绿素总量随着水分胁迫的加剧逐渐减低,严重水分胁迫时,紫穗槐叶绿素a、叶绿素b、叶绿素总量最低,分别比正常水分(土壤含水量为田间最大持水量的80%)时下降了1.61、0.35、1.96 mg·g-1;樟子松和紫穗槐脯氨酸、丙二醛(MDA)含量和相对电导率随着干旱胁迫强度的增加而增加。综合结果表明,樟子松抗旱性比紫穗槐强。

With a potting experiment,physiological indicators including leaf water potential ,chlorophyll （Chl）,proline,malondialde-hyde（MDA） and relative conductivity of sand Amorpha fruticosa and Pinus sylvestris var.mongolica were measured in different water conditions.The results showed that：With the deepening of water stress , water potential of Amorpha fruticosa and Pinus sylvestris var.mongolica decreased;Contents of chlorophyll a ,chlorophyll b and total chlorophyll of Pinus sylvestris var.mongolica increased under light water stress （ soil moisture content is 65% of field water-holding capacity ） , and then decreased gradually , contents of chlorophyll a ,chlorophyll b and total chlorophyll were 0.50 mg？ g-1、0.16 mg？ g-1 and 0.66 mg？ g-1 under severe water stress （ soil moisture content is 35%of field water-holding capacity ） ,with the deepening of water stress ,contents of chlorophyll a ,chloro-phyll b and total chlorophyll of Amorpha fruticosa decreased gradually and were the lowest under severe water stress , decresed by 1.61 mg？ g-1、0.35 mg？ g-1 and 1.96 mg？ g-1 ,compared with the normal water （ soil moisture content is 80%of field water-hold-ing capacity）.With the deepening of water stress ,the content of proline,MDA and relative conductivity of Amorpha fruticosa and Pi-nus sylvestris var.mongolica increased.Obviously ,Pinus sylvestris var.mongolica was better in drought resistance than Amorpha fruti-cosa through comparison of each physiological index .