【作者】 李倩；

【导师】 贺康宁；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2017， 硕士

【摘要】 在盐碱化土地日趋扩大的背景下,耐盐植物的培育和种植变得愈发重要,本文选取藜科(Chenopodiaceae)滨藜属的四翅滨藜(Atriplex canescens)为研究对象,以青海省柴达木盐碱地为研究区,采用室内盆栽的方法对四翅滨藜施加NaCl和Na2SO42种不同的盐分处理,设置0,100,200,300,400 mmol·L-1的浓度梯度,以测定在不同种类以及不同浓度的盐渍环境中四翅滨藜的生长状况、渗透能力及光合特性对盐胁迫的反映机理,系统研究盐分胁迫对四翅滨藜生长及生理差异影响的机制,得到以下主要结论:(1)本研究拟采用在四翅滨藜幼苗的净光合速率达到最大值时的土壤水分含量作为四翅滨藜生长的最适水分,通过净光合速率与土壤水分含量的拟合,再进行计算得到四翅滨藜幼苗正常生长的最适水分条件为18%的土壤含水量;(2)四翅滨藜是一种具有极强耐盐能力的盐生树种,随着盐分浓度的升高,四翅滨藜幼苗的株高、地径及生物量增量表现为先增大后减小的趋势,与对照相比,盐浓度为100-300 mmol·L-1的NaCl和Na2SO4盐处理均不同程度地对幼苗的生长起到了促进作用,而当盐浓度达到400mmol·L-1时,四翅滨藜幼苗的生长又受到了不同程度的抑制作用,且抑制程度为NaCl大于Na2SO4;(3)在NaCl和Na2SO4 2种盐处理下,与对照相比,四翅滨藜幼苗的净光合速率与叶绿素含量均表现为随着盐浓度的升高而逐渐增大的趋势,即在100-400mmol·L-1的浓度范围内盐浓度越高对净光合速率及叶绿素含量的促进程度越强,且促进效果表现为Na2SO4大于NaCl。而四翅滨藜幼苗的蒸腾速率及气孔导度在盐处理下表现为先增大后减小的趋势,100-200 mmol·L-1处理时均显著高于对照,且增大幅度为NaCl<Na2SO4;当浓度达到300或400 mmol·L-1又低于对照,降低幅度为NaCl大于Na2SO4;(4)与对照相比,四翅滨藜幼苗的脯氨酸、丙二醛、可溶性糖、可溶性蛋白及SOD、POD2种酶活性在NaCl和Na2SO42种盐处理下,随着盐浓度的升高均呈现出不同程度的增大,在100-300mmol·L-1范围内的增大幅度总体表现为NaCl>Na2SO4,这表明四翅滨藜幼苗在NaCl环境下遭受的伤害更大;(5)应用回归分析,计算出NaCl处理下四翅滨藜幼苗生长的最适宜浓度范围是0-272.6 mmol·L-1,Na2SO4处理下四翅滨藜幼苗生长的最适宜浓度范围为0-321.9 mmol·L-1,可以得到以硫酸盐为主的盐碱地四翅滨藜能够正常生长的适宜浓度范围更大。更多还原

【Abstract】 Under the background of increasing salinization of the land,the cultivation of salt-tolerant plants are becoming increasingly important.This paper chooses Atriplex canescens of Chenopodiaceae as the research object,choosing Qaidam saline region of Qinghai Province as the research area.Using indoor pot control method,NaCl and Na2SO4 salt treatments were respectively applied to Atriplex canescens and set 0,100,200,300 and 400 mmol·L-1 concentration gradient.Measuring the growth index,penetration ability and photosynthetic characteristics of Atriplex canescens under different salt condition.To study the effects of salt treatment on the growth and physiological differences of Atriplex canescens.Get the following main conclusions:(1)In this study,the soil moisture content at the maximum net photosynthetic rate was used as the optimum moisture for the growth of Atriplex canescens seedings,fitting the net photosynthetic rate with the soil water content,and then calculate to get the optimum soil moisture condition for normal growth of Atriplex canescens seedings is 18%;(2)Atriplex canescens is a saline specie with strong salt resistance ability,with the increase of salt concentration,the plant height,ground diameter and biomass increment were increased first and then decreased.Compared with the control,the treatment of NaCl and Na2SO4 with salt concentration of 100-300 mmol·L-1 promoted the growth of seedlings to some extent,when the concentration of salt reaches 400 mmol·L-1,the growth of Atriplex canescens seedings has been inhibited to some extent,and the inhibition degree of NaCl was greater than Na2SO4;(3)Under NaCl and Na2SO4 two kinds of salt treatments,compared with the control,the net photosynthetic rate and chlorophyll content ofAtriplex canescens seedings showed a tendency to increase with the increase of salt concentration,in the concentration range of 100-400mmol·L-1,the higher the salt concentration,the stronger net photosynthetic rate and chlorophyll content,and the promotion degree of Na2So4 is greater than NaCl.While the transpiration rate and stomatal conductance oF Atriplex canescens seedings showed a tendency to increase first and then decreased,100-200 mmol·L-1 were significantly higher than the control,and the increase degree of NaCL was less than Na2SO4.When the concentration reached 300 or 400 mmol·L-1 was lower than the control,and the reduce degree of NaCl was less than Na2SO4.(4)Compared with the control,the proline,malondialdehyde,soluble sugar,soluble protein,SOD and POD activity of Atriplex canescens seedings were increased differently with the salt concentration increased under NaCl and Na2SO4 salt treatments.The increase in the range of 100-300 mmol·L-1 showed NaCl was greater than Na2SO4,That indicated the Atriplex canescens seedlings suffered more damage in the NaCl environment;(5)Applied regression analysis,get the optimum concentration range for Atriplex canescens seedings growth under NaCl treatment was 0-272.6mmol L’1,under Na2SO4 treatment was 0-272.6mmol·L-1,so the most optimum concentration range is larger of Atriplex canescens seedings growth normally in sulfate saline-alkali soil.更多还原