【作者】 李彩霞；

【导师】 蒋志荣；

【作者基本信息】 甘肃农业大学 ， 水土保持与荒漠化防治， 2007， 硕士

【摘要】 本文对四翅滨藜(Atriplex canes cens[Pursh]Nute)、多枝柽柳(Tamarix ramosissima )、梭梭(Haloxylon ammodendron)的耐盐机理进行了系统研究。研究选取了成活率、游离脯氨酸、可溶性糖、可溶性蛋白、Na~+浓度、K~+浓度、膜透性、丙二醛、SOD、CAT、POD、叶绿素、净光合速率、气孔导度,蒸腾速率等15个指标进行测定。旨在探讨三种灌木的耐盐机理并进行耐盐性评价,从而为张掖地区的四翅滨藜引种与治沙造林提供理论依据。研究结果如下:1)对三种灌木成活率的调查表明,随着盐胁迫强度的加大,盐胁迫时间的延长,三种灌木的成活率都呈现下降趋势,但是四翅滨藜的成活率明显高于多枝柽柳与梭梭,说明四翅滨藜具有较好的耐盐性。2)在试验中,三种灌木遭受盐胁迫后,作为渗透调节物质的可溶性蛋白的变化较明显,而游离脯氨酸和可溶性糖的变化不是很明显。三种灌木相比较,四翅滨藜在胁迫过程中对Na~+的积累小于多枝柽柳和梭梭,而对K~+的积累高于多枝柽柳和梭梭,说明仅从渗透调节物质来看,四翅滨藜的耐盐性大于多枝柽柳和梭梭。3)在盐胁迫下,膜系统的稳定性与完整性遭到破坏,失去对离子的选择性,有害离子大量进入,导致叶片细胞膜透性增大,电导率升高,细胞膜发生过氧化作用,本试验中,梭梭与多枝柽柳的膜透性明显大于四翅滨藜,即:四翅滨藜在盐胁迫下的膜伤害小于梭梭和多枝柽柳。4)在盐胁迫下,三种灌木的SOD、POD均表现为先升后降的趋势,并且以多枝柽柳的变化幅度最大,四翅滨藜的次之,梭梭的最小。说明在低盐胁迫下,SOD、POD、CAT能够及时的清除植物体内的氧自由基,但是在高盐胁迫下,SOD、CAT活性钝化,失活和破坏,导致膜不稳定性增加,同时,植物体内酶的活性与它们本身的特性有关。5)盐胁迫下, 3种灌木的气孔导度及净光合速率对盐胁迫反应非常敏感,在低盐胁迫下就表现出与对照明显不同。梭梭、多枝柽柳与四翅滨藜相比,其叶片色素的稳定性较差,它含量的降低也造成了光合速率的降低。但是三种灌木相比,其光合速率的下降幅度以多枝柽柳最大,四翅滨藜次之,梭梭的最小。6)主成分分析表明:多枝柽柳的第一主成分是丙二醛含量、膜透性、气孔导度、蒸腾速率、可溶性糖、可溶性蛋白;四翅滨藜的第一主成分是光合速率、气孔导度、蒸腾速率、丙二醛、钾含量;梭梭的第一主成分是丙二醛、钾含量、叶绿素总量、SOD、POD、可溶性蛋白。7)通过对与三种灌木相关的14个耐盐性生理指标的测定,应用模糊数学隶属法对三种灌木的耐盐性进行综合评价,评价结果表明:三种灌木的耐盐性排序依次为:四翅滨藜>多枝柽柳>梭梭综上所述,四翅滨藜作为一种优良的耐盐品种可以在张掖地区引入。更多还原

【Abstract】 The experiment studied Salt-tolerant Mechanism on Atriplex canes cens , Tamarix ramosissima and Haloxylon ammodendron systematically. Fifteen indices were tested including the followings: survivalrate, free Proline,solube sugar,soluble proteins, Na+content , K~+ content, membrane permeability, MDA content, SOD activity, POD activity,CAT activity, Chlorophyll,net photosynthetic rate, transpiration rate and stomatal conductance,in order to find out inherent mechanisms of salt tolerance of the three kinds of shrubs and provide theoretics basis of introduction of Atriplex canes cens in zhang ye area.The results showed that:(1) The survivalrate investigation showed that :the survivalrate decreased with the salt stress.the survivalrate of Atriplex canes cens was higher than the other species,so Atriplex canes cens had better salt resistance.(2)In this experiment, During the process of salt stress, the change of Soluble proteins which is one of the Osmoregulation substance is significant,however,the changes of free Proline content and the Soluble sugar were not significant., the Na+content of Atriplex canes cens was less than Tamarix ramosissima and Haloxylon ammodendron.and the K+content of Atriplex canescens more than Tamarix ramosissima and Haloxylon ammodendron. So from the angle ofOsmoregulation substance, Atriplex canescens had better salt resistance.(3) During the process of salts stress,stability and the completeness of cell membrane system were damaged, losing the choice to the ions ,and pernicious ions greats quantity were absorbed. It is the main reason of the great quantity of plant that cell membrane system were seriously damaged in high salt stress treatment.The membrane permeability of Atriplex canes cens was less than the other species,so the membrane injury was less than the other species.(4) During the process of salts stress,the SOD、POD activities increased first ,then decreased. The range of variation of Tamarix ramosissima was larger than Atriplex canes cens and Haloxylon ammodendron. SOD,CAT, POD can clean out oxygen free radical timely under low salt tolerance. But during the process of high salt stress ,SOD, CAT, POD activity were deactivated,activity lost and damaged,which causes the membrane system instable. At the same time,the activities of Enzyme in the body of plants were related with themself.(5) During the process of salts stress, photosynthetic rate and stomatal conductance was very sensitive to salts stress, they were different between low salt tolerance and high salt stress.The stability of Chlorophyll in Tamarix ramosissima and Haloxylon ammodendron was not as good as Atriplex canes cens, and the photosynthetic rate of Atriplex canes cens decreased more than Haloxylon ammodendron,but less than Tamarix ramosissima.(6) The primary component analysis indicates:The primary components of Tamarix ramosissima were MDA, membrane permeability, stomatal conductance , net transpiration rate , solube sugar, soluble proteins. The primary components of Atriplex canes cens were net photosynthetic rate, stomatal conductance, transpiration rate ,MDA. The primary components of Haloxylon ammodendron were MDA, K+content,chlorophyll content,SODactivity ,PODactivity, solube proline.(7) Applying the method of Fuzzy integrative evaluation to evaluated the salt tolerance of the three kinds of shrubs ,the result showed that the Atriplex canes cens > Tamarix ramosissima lour > Haloxylon ammodendron .Evaluating the tolerance of the three kinds of shrubs,we can make the conclusion as follow: Atriplex canescen can be introducted as a excellent breed variety of salt tolerance in Zhang ye area.更多还原