半红树植物杨叶肖槿幼苗耐盐性研究

Salt Tolerance of Semi-mangrove Plant Thespesia populnea Seedlings

温室内对半红树植物杨叶肖槿幼苗进行7个盐度(5、8、11、14、17、20、23 g.kg-1)的胁迫处理,并对各处理下杨叶肖槿的生长量、生物量、生理指标和光合速率进行测定,结合生理指标进行适应度分析。结果表明:杨叶肖槿的苗高、地径、叶片数、根、茎、叶干质量及总生物量随着盐度的上升均呈下降趋势,在盐度为5、8 g.kg-1处理下保持较高值,盐度超过11 g.kg-1后骤降;光合速率在盐度为5、8、11 g.kg-1处理下保持较高值,最大值出现在盐度为8 g.kg-1的处理;随着盐度的增大,杨叶肖槿幼苗叶绿素总量、叶绿素A含量和根活力呈下降趋势,超氧化物歧化酶(SOD)、丙二醛和游离脯氨酸呈上升趋势。生理指标适应度分析表明:杨叶肖槿可耐受的盐度为8 g.kg-1,在盐度≥11 g.kg-1时呈不适应性生长。

Thespesia populnea seedlings were treated with seven salt gradients including 5,8,11,14,17,20,and 23 g·kg^-1in greenhouse.The increment,biomass,physiological indexes and photosynthetic rate of Thespesia populnea seedlings with different salinity treatments were determined,combined with the adaptability analysis of physiological indexes.The results showed that the height,stem,leaf,root dry weight,stem dry weight,leaf dry weight and total biomass decreased with increasing of the salt,and they kept high values when the treatment salt were 5 and 8 g·kg^-1but they decreased suddenly when the treatment salt were more than 11 g·kg^-1The photosynthesis of Thespesia populnea seedlings were high under the salt treatment of 5,8 and 11 g·kg^-1and the maximum value was under the salt treatment of 8 g·kg^-1With the increasing of salinity,the SOD,free proline and MDA increased,but chlorophyll,chlorophyll A and root activity decreased.The adaptability analysis of physiological indicator showed that Thespesia populnea seedlings grew normally when the treatment salt was no more than 8 g·kg^-1and the growth would be inhibited when the salinity was more than 11 g·kg^-1