不同中性钠盐对紫背天葵幼苗生长和光合特性的影响

Effects of Different Neutral Sodium Salt Stress on Begonia fimbristipula Seedlings Growth and Photosynthetic Characteristics

为探究紫背天葵(Begonia fimbristipula Hance)的抗盐性,并为紫背天葵栽培选择适宜的盐环境提供科学依据,选择NaCl和Na_(2)SO_(4)以及二者混合的复合盐(摩尔比1∶1),设置浓度分别为0.02,0.04,0.06,0.08,0.10 mol·L^(-1),对紫背天葵幼苗进行盐胁迫,分析它们对紫背天葵幼苗生长和光合作用的影响。结果显示:3种钠盐都对紫背天葵幼苗生长造成伤害,而且浓度越高,伤害越大。当盐浓度≤0.04 mol·L^(-1)时,复合盐对紫背天葵幼苗的伤害程度小于NaCl和Na_(2)SO_(4)。NaCl、Na_(2)SO_(4)胁迫后,紫背天葵幼苗叶片叶绿素含量、净光合速率、蒸腾速率、气孔导度均随浓度升高而降低,且Na_(2)SO_(4)的降幅高于NaCl。复合盐胁迫下,随着浓度升高,叶绿素含量和净光合速率先升高后降低,蒸腾速率和气孔导度持续降低。胞间CO_(2)浓度在NaCl胁迫下先降低后升高,而Na_(2)SO_(4)和复合盐胁迫下呈升高趋势。综合分析得出,紫背天葵对复合盐的抗性明显高于NaCl和Na_(2)SO_(4)2种单盐。

To explore the salt resistance of Begonia fimbristipula Hance,and provide scientific reference for choosing the adequate salty soil when planting the B.fimbristipula.NaCl,Na_(2)SO_(4) and their mixed salts(NaCl∶Na_(2)SO_(4)=1∶1)were selected to stress B.fimbristipula seedlings with the different concentration of 0.02,0.04,0.06,0.08,0.10 mol·L^(-1) respectively,the effects of the three kinds of neutral sodium salt stress on the growth and photosynthetic characteristics of B.fimbristipula seedlings had analyzed.The results showed that all three kinds of sodium salt hurt the B.fimbristipula seedlings and the higher the salt concentration,the worse the damage.But when the concentration was lower than or equal to 0.04 mol·L^(-1),the degree of damage of mixed salt to the seedlings was less than that of NaCl and Na_(2)SO_(4).The chlorophyll content(SPAD),the net photosynthetic rate(Pn),transpiration rate(Tr),and stomatal conductance(Gs)of the leaves decreased with the increase of salt concentration stressed by NaCl and Na_(2)SO_(4),and the drop level stressed by Na_(2)SO_(4) was more than stressed by NaCl.While stressed by mixed salt,SPAD and Pn increased first then decreased,Tr and Gs decreased with the increase of the salt concentration.Intercellular carbon dioxide concentration(Ci)decreased first then increased stressed by NaCl,while Ci showed upward trend stressed by Na_(2)SO_(4) and mixed salt.It is finally determined that the resistance of B.fimbristipula seedlings to the mixed salt was significantly higher than that of NaCl and Na_(2)SO_(4).