混合盐碱胁迫对紫花苜蓿幼苗生长和生理特性的影响  

Effects of mixed saline-alkali stress on growth and physiological characteristics of Medicago sativa seedlings

作　　者：于明倩 胡亚娜 田雨[1] YU Mingqian;HU Yana;TIAN Yu(College of Animal Science and Technology,Jilin Agricultural University,Changchun 130118,China)

机构地区：[1]吉林农业大学动物科学技术学院,长春130118

出　　处：《黑龙江畜牧兽医》2021年第22期109-112,共4页Heilongjiang Animal Science And veterinary Medicine

基　　金：吉林省科技发展计划重点科技研发专项(20210202070NC)。

摘　　要：为了探究紫花苜蓿在混合盐碱胁迫下的生长及生理特性,试验将两种中性盐(NaCl、Na_(2)SO_(4))和两种碱性盐(NaHCO_(3)、Na_(2)SO_(4))按摩尔比1∶1∶1∶1混合,配制50,100 mmol/L两个浓度的混合盐碱溶液对紫花苜蓿幼苗进行盐碱胁迫15 d,测定幼苗各器官(根、茎、叶)生物量,计算根冠比;测定幼苗叶绿素a、叶绿素b和类胡萝卜素含量,计算叶绿素a/叶绿素b;测定幼苗的光合速率、气孔导度、胞间CO_(2)浓度和蒸腾速率,计算上述光合参数的相对降低率和升高率;测定幼苗根系活力,Na^(+)、K^(+)、脯氨酸和丙二醛含量,计算Na^(+)、K^(+)。结果表明:紫花苜蓿幼苗各器官生物量、叶绿素a和叶绿素b含量、光合速率、气孔导度、蒸腾速率、根系活力随盐碱胁迫浓度升高呈逐渐降低的趋势,Na^(+)、K^(+)、胞间CO_(2)浓度、丙二醛含量呈逐渐升高趋势,脯氨酸含量呈先降低后升高的趋势。说明盐碱胁迫抑制了紫花苜蓿的生长发育,降低了光合作用,但是植株可以通过生物量分配调整、钾离子外排增强耐盐碱能力,减轻盐碱胁迫对紫花苜蓿的伤害。In order to investigate the growth and physiological characteristics of Medicago sativa seedlings under mixed saline-alkali stress,the seedlings were subjected to saline-alkali stress by mixed-saline-alkali solutions at the concentration of 50,100 mmol/L(NaCl、Na_(2)SO_(4)∶NaHCO_(3)∶Na_(2)CO_(3)=1∶1∶1∶1∶1)for 15 d.The biomass of the organs(root,stem and leaf)of seedlings was measured and the ratio of root to crown was calculated;The contents of chlorophyll a,chlorophyll b and carotenoids in seedlings were measured,and the ratio of chlorophyll a/chlorophyll b was calculated.The photosynthetic rate,stomatal conductance,intercellular CO_(2)concentration and transpiration rate of seedlings were measured,and the relative reduction rate and increase rate of the above photosynthetic parameters was calculated.The root activity,Na^(+)、K^(+),proline and malondialdehyde contents of seedlings were measured,and Na^(+)、K^(+)was calculated.The results showed that the biomass,contents of chlorophyll a,b,photosynthetic rate,stomatal conductance,transpiration rate and root activity of Medicago sativa seedlings decreased gradually with the increase of mixed-saline-alkali concentration.Na^(+)、K^(+),intercellular CO_(2)concentration and MDA content increased with the increase of mixed-saline-alkali concentration,while proline content decreased first and then increased.The results indicated that the growth and development of Medicaga sativa was inhibited and its photosynthesis was reduced under mixed-saline-alkali stress,and plants could reduce the damage of alfalfa under salt-alkali stress by enhancing salt-alkali tolerance through adjusting biomass allocation and potassium ion efflux.

关 键 词：紫花苜蓿 盐碱胁迫 光合特性 生理适应 根系活力 生物量分配 

分 类 号：S816.5[农业科学—饲料科学]