盐胁迫对菠萝蜜幼苗生长及生理特性的影响

Effect of Salt Stress on the Growth and Physiological Characteristics of Young Jackfruit Seedlings

为研究盐胁迫对菠萝蜜幼苗生长和生理特性的影响,为盐碱地开发利用提供参考。以菠萝蜜幼苗为试材,采用基质栽培法,在茎粗达到0.8 cm时,进行盐胁迫处理(NaCl浓度分别为3.4 g·kg^(-1)、10.2 g·kg^(-1)、17.0 g·kg^(-1)、23.8 g·kg^(-1)、30.6 g·kg^(-1)和37.4 g·kg^(-1)),研究盐胁迫下菠萝蜜幼苗生长及生理指标的变化。结果表明,NaCl 3.4 g·kg^(-1)胁迫下,菠萝蜜的叶片受害程度较低,NaCl 10.2 g·kg^(-1)胁迫下,叶片受害程度开始明显显现,并随着胁迫时间的延长叶片出现叶缘枯焦,叶片枯黄的现象;在处理的第24 d,NaCl 37.4 g·kg^(-1)下的菠萝蜜幼苗叶片全部掉落,在处理的第30 d,植株死亡;NaCl 30.6 g·kg^(-1)下的菠萝蜜幼苗叶片在处理的第30 d叶片全部落掉;此研究表明盐胁迫显著抑制菠萝蜜幼苗生长、降低叶绿素含量和自由水的变化,随着胁迫浓度及胁迫时间的延长,菠萝蜜叶片的可溶性糖、可溶性蛋白、束缚水和SOD酶均呈现先上升后下降的趋势,而电导率、MDA含量均呈现上升趋势。经生理指标的相关性和主成分分析,盐胁迫对叶绿素、自由水、束缚水、电导率、MDA含量、SOD酶活性和可溶性糖含量的影响显著,可作为菠萝蜜抗盐性分析的参考指标。

To study the effect of salt stress on the growth and physiological characteristics of young jackfruit seedlings,and to provide references for the development and utilization of saline-alkali land,young jackfruit seedlings with stem diameter of 0.8 cm were cultivated in substrate as the test material and were treated by salt stress treatment(salt concentration was 3.4 g·kg^(-1),10.2 g·kg^(-1),17.0 g·kg^(-1),23.8 g·kg^(-1),30.6 g·kg^(-1) and 37.4 g·kg^(-1)).Changes of the growth and physiological indexes of young jackfruit seedlings under salt stress were studied.The results showed that leaves under the stress of NaCl 3.4 g·kg^(-1) concentration were damaged at the low level,leaves under NaCl 10.2 g·kg^(-1) showed obvious damage,and the leaf margin became withered and leaves became yellow with the extension of stress time.All the leaves fell on the 24th d and the plants died on the 30th d after treatment by NaCl 37.4 g·kg^(-1).All the leaves fell on the 30th d after treatment by NaCl 30.6 g·kg^(-1) leaves.This study shows that salt stress significantly inhibited young jackfruit seedling growth,reduced chlorophyll content and free water.With the extension of concentration and time of stress,the soluble sugar,soluble protein,binding water and SOD all rose first and then declined,while the electrical conductivity and MDA content all showed the upward trend.Correlation of physiological indicators and main component analysis showed,salt stress had significant effects on chlorophyll,free water,bound water,conductivity,MDA content,SOD activity and soluble sugar content,which can be used as reference indices for the salt resistance of jackfruit.