盐胁迫对燕麦幼苗生长,K^+、Na^+吸收和光合性能的影响

Effects of Salt Stress on Oat Seedling Growth and Selective Absorption of K^+ and Na^+ and Photosynthetic Characters

采用NaCl与Na2SO4不同盐分含量进行盆栽试验。盐胁迫下,植株生长受到明显的抑制,受盐胁迫影响程度的顺序是单株干质量>单株绿叶面积>株高;叶片中叶绿素(Chl)含量随着土壤含盐量的增加呈下降趋势,小于0.3%含盐量的下降幅度大于高盐胁迫,盐胁迫对叶绿素b(Chlb)的影响大于叶绿素a(Chla);燕麦幼苗的离子运输具有选择性,根具有贮Na+的作用,茎具有贮K+的功能,随着盐胁迫的加强,各器官K+的含量在逐渐下降,Na+的含量逐渐上升,大于0.6%盐胁迫幼苗丧失了对离子的选择性。盐胁迫Pn、WUE呈下降趋势,Gs、Tr和Ci的变化趋势是低盐胁迫下升高、高盐胁迫下降低。0.2%盐胁迫可促进燕麦幼苗生长和光合能力加强;燕麦对于0.3%含盐量有一定的耐性;大于0.3%盐胁迫时,燕麦幼苗生理代谢受到严重影响;大于0.5%盐胁迫时,光合受阻,生长受到严重抑制。

The pot plant experiment were conducted with different salt（NaCl and Na2SO4） concentration.The plant growth under salt stress were obviously inhibited,the order was plant height 〉leaf area per plant 〉dry weight per plant;The contents of chlorophyll（Chl） showed downtrend with the increase of salt content,less than salt concentration 0.3% it was decreased faster than high salt stress,the effect of chlorophyll b under salt stress is stranger than chlorophyll a;Oat seedling have selective absorption to ion transportation,root can storage Na＋ and stem can storage K＋,each organ＇s K＋ content decreased and Na＋ increased gradually with the strengthen of salt stress,amplitude variation order was leaf 〉stem〉 root.Over 0.6% salt concentration oat seedling lost selective absorption to ion.Net photosynthetic rate（Pn）and water use efficiency（WUE） showed downtrend under salt stress,the changing trend of trendstomatal conductance（Gs） and transpiration rate（Tr） and intercellular CO2 concentration（Ci） was increased at low salt and decreased at high salt stress.Salt concentration 0.2% can improve oat seedling growth and photosynthetic characters;Salt concentration 0.3% can increase the endurances;More than salt concentration 0.3% oat seedling physiological was metabolism significantly influenced;More than salt concentration 0.5% photosynthetic was hindered and growth was seriously inhibited.