摘要
为研究添加不同浓度的有机酸对棉花苗期生理特征和根系分泌物中有机酸的影响,本研究使用喀什市伽师县采集的两种盐碱土壤,总盐12.8 g/kg(中度盐碱土)和总盐19.3 g/kg(重度盐碱土),设置 5、10 mmol/L有机酸添加浓度,分别添加草酸、乙酸、抗坏血酸和甲酸4种有机酸,以不添加有机酸作为对照组,共18个处理,利用盆栽试验研究盐碱土添加不同种类的有机酸对棉花根系中丙二醛、渗透调节物质、抗氧化酶和根系分泌物中有机酸含量的影响.结果表明,外源有机酸可以显著降低土壤pH值(P<0.05),随着盐度增加苗期棉花根系丙二醛、可溶性糖、可溶性蛋白、脯氨酸含量上升,外源有机酸处理后显著降低根系丙二醛含量(降低幅度11.4%～38.4%)(P<0.05),显著增加渗透调节物质和抗氧化酶活性(P<0.05),改变棉花苗期根系分泌物中有机酸的组成,显著促进草酸的分泌(P<0.05),表明草酸是响应盐碱的主要有机酸.综合以上指标,外源草酸、乙酸、抗坏血酸和甲酸可以缓解盐碱土对棉花苗期的损伤,其中添加5 mmol/L草酸效果最佳.
Abstract
To study the effects of adding different concentrations of organic acids on physiological charac-teristics and organic acids in root exudates of cotton at the seedling stage by using two kinds of saline-alkali soils collected in Jishi County,Kashgar City,with salinity of 12.8 g/kg(medium saline-alkali soil)and sa-linity of 19.3 g/kg(heavy saline-alkali soil).The addition concentrations of 5 mmol/L and 10 mmol/L or-ganic acids were set,and four organic acids,oxalic acid,acetic acid,ascorbic acid,and formic acid were added respectively,with no organic acid added as the control group.A total of 18 treatments were performed.Then the effects of adding different kinds of organic acids under saline-alkali soil on the contents of malon-dialdehyde,osmotic regulator,antioxidant enzyme,and organic acids in pot experiment cotton were stud-ied.The results showed as follows:With the increase of salinity,exogenous organic acids could significant-ly reduce soil pH(P<0.05),the contents of malondialdehyde,soluble sugar,and soluble protein proline in cotton root at the seedling stage increased,and the content of malondialdehyde in cotton root after exoge-nous organic acid treatment was significantly decreased(decreased by 11.4%-38.4%)(P<0.05),and the activities of osmoregulatory substances and antioxidant enzymes were significantly increased(P<0.05).The composition of organic acids in root exudates of cotton at a seedling stage significantly promo-ted oxalic acid secretion(P<0.05),indicating that oxalic acid was the main organic acid responding to salt and alkali.According to the above indexes,exogenous oxalic acid,acetic acid,ascorbic acid,and formic acid can alleviate the damage of saline-alkali soil in the cotton seedling stage,and the addition of 5 mmol/L ox-alic acid has the best effect.
基金项目
国家重点研发专项(2021YFD1900802-4)
NETL
NSTL
万方数据