镉胁迫下青葙种子萌发及幼苗生理特性  

Seed germination and seedling physiological characteristics of Celosia argentea under cadmium stress

作　　者：胡佳瑶 王悟敏 匡雪韶 刘文胜[1] HU Jiayao;WANG Wumin;KUANG Xueshao;LIU Wensheng(School of Life Sciences and Technology,Central-South University of Forestry and Technology,Changsha 410004,Hunan,China)

机构地区：[1]中南林业科技大学生命科学与技术学院,湖南长沙410004

出　　处：《草业科学》2022年第7期1391-1398,共8页Pratacultural Science

基　　金：国家自然科学基金项目(42177018);湖南省自然科学基金项目(2021JJ31147);湖南省教育厅项目(20C1917)。

摘　　要：青葙(Celosia argentea)为苋科一年生草本植物,是重金属镉的超富集植物,具有观赏价值高、抗逆性强等特点,是一种镉污染土壤修复的重要候选植物。为揭示青葙对镉胁迫的适应性特征及生理机理,研究不同镉浓度(0、50、100、200、500μmol·L^(-1))对其种子萌发、幼苗生长及生理特征的影响。结果表明:镉对青葙种子发芽率和萌发势影响较小,但降低了发芽指数、活力指数和生物量;青葙在镉胁迫下整体长势良好;随着镉浓度的升高,叶绿素a、叶绿素b和类胡萝卜素含量均下降;随着镉浓度升高,超氧化物歧化酶、过氧化物酶和过氧化氢酶活性以及游离脯氨酸含量呈先上升后下降的趋势,可溶性糖、可溶性蛋白和丙二醛含量则逐渐升高。研究结果表明,青葙具有较强的耐镉能力,能通过提高抗氧化酶活性和调控体内的渗透调节物质含量来缓解镉带来的毒害作用。Celosia argentea is an annual herb belonging to the family Amaranthaceae.It is a cadmium(Cd)hyperaccumulator,with high ornamental value and strong stress resistance.It is an important plant candidate for the remediation of Cdcontaminated soils.To reveal the adaptive characteristics and physiological mechanisms of C.argentea under Cd stress,the effects of different Cd concentrations(0,50,100,200,and 500μmol·L^(-1))on seed germination,seedling growth,and physiological characteristics were studied.The results showed that Cd had little effect on seed germination rate and germination potential,but decreased the germination index,vigor index,and biomass.Celosia argentea grew well under Cd stress.With an increase in Cd concentration,the contents of chlorophyll a,chlorophyll b,and carotenoids decreased.With an increase in cadmium concentration,the activities of superoxide dismutase,peroxidase,and catalase,and the content of free proline first increased and then decreased,while the contents of soluble sugar,soluble protein,and malondialdehyde gradually increased.The results suggest that C.argentea exhibits strong cadmium tolerance and can alleviate the toxic effects of cadmium by improving the activity of antioxidant enzymes and regulating the content of osmoregulatory substances in the body.

关 键 词：镉胁迫 青葙 种子萌发 幼苗生长 生理指标 渗透调节物质 抗氧化酶活性 

分 类 号：X173[环境科学与工程—环境科学] X53[生物学—植物学] Q948