外源硼对干旱胁迫下厚皮甜瓜幼苗生长和抗氧化系统的影响

Effects of exogenous boron on the growth and antioxidant system of muskmelon seedlings under drought stress

为了探究外源硼对干旱胁迫下厚皮甜瓜幼苗生长和抗氧化系统的影响,采用沙培育苗的方法,以相对含水量为20%的河沙模拟干旱条件,在厚皮甜瓜幼苗三叶一心期,叶面喷施5、10、20、40 mmol/L 4种不同浓度的硼砂溶液,以清水作为对照,研究了干旱胁迫下外源硼对厚皮甜瓜幼苗生长和抗氧化系统的影响。结果表明,与对照相比,叶面喷施不同浓度的硼砂均能在一定程度上提高干旱胁迫下厚皮甜瓜幼苗的株高、茎粗、叶面积、气孔导度、光合色素含量、叶片蒸腾速率、胞间CO_(2)浓度等生长和生理指标,增强了叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性,降低了超氧阴离子的活性和丙二醛(MDA)含量;其中,以浓度为20 mmol/L硼砂处理较对照和其它浓度处理效果最佳。

This study investigated the effects of exogenous borax on muskmelon seedling growth and antioxidant system under drought stress.In this experiment,sand cultivation with a relative water content of 20%was used to simulate drought condition.The muskmelon seedling leaves were sprayed with borax solutions under concentrations of 5,10,20,40 mmol/L during the third-leaf stage.Phenotypic comparetion showed that exogenous borax increased the plant height,stem thickness,leaf area,stoma conductance,photosynthetic pigment content and leaf transpiration of muskmelon seedlings under drought stress.The leaf superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)activity increased and the activity of superoxide anion and malondialdehyde(MDA)content reduced in response to exogenous borax treatment under drought.Comparitively,the treatment with a concentration of 20 mmol/L borax has the best effect than the control and other concentration treatments.