苗期白羊草对盐胁迫的生理生化响应及其耐盐阈值的界定  

Physiological and biochemical responses of Bothriochloa ischaemum seedlings to salt stress at seedling stage and definition of salt tolerance threshold

作　　者：高守舆 刘文静[1] 李钰莹[1] 向清源 许佳俊 舒蕾淇 李肇中 GAO Shou-yu;LIU Wen-jing;LI Yu-ying;XIANG Qing-yuan;XU Jia-jun;SHU Lei-qi;LI Zhao-zhong(College of Grassland Science,Shanxi Agricultural University,Jinzhong 030801,China)

机构地区：[1]山西农业大学草业学院,山西晋中030801

出　　处：《草业学报》2025年第3期164-174,共11页Acta Prataculturae Sinica

基　　金：山西省重点研发计划项目课题“白羊草等优良乡土禾草抗逆基因资源挖掘及创新利用(202102140601006-2)”;山西农业大学“十四五”生物育种工程项目“乡土草种质资源挖掘与新品种选育(YZGC134)”资助。

摘　　要：土壤盐渍化是我国北方草业发展的重要限制因素之一,开发抗盐碱能力强的乡土草种质资源,是解决盐碱地资源化利用的有效手段。为探究苗期白羊草的抗盐机制及其耐盐阈值,本研究以苗期‘太行’白羊草为材料,设置9个NaCl浓度盐胁迫处理,测定其株高、根长、地上部生物量等13个指标,并利用主成分分析计算其耐盐阈值。结果表明,NaCl胁迫对白羊草地上部生长影响更大,但地下部对Na+、K+的响应更为敏感。在胁迫时间和NaCl浓度两个维度上,叶片中过氧化物酶和超氧化物歧化酶活性均呈先升后降的趋势,并于210 mmol·L^(-1)NaCl处理下的第8和10天分别达到最大值;丙二醛、可溶性糖含量呈升高趋势;叶绿素含量呈下降趋势。通过主成分分析选取分数集前二的指标(根长和干重)建立回归曲线,经验证后发现地上部干重更适合作为评价耐盐阈值的指标,得出白羊草的耐盐阈值为207.53 mmol·L^(-1)。本试验将为禾本科植物耐盐机制研究和后续探究白羊草抗盐机制研究的试验处理时间提供参考依据。Soil salinization is one of the important limiting factors restricting the development of the pastoral industry in northern China.Developing local grass germplasm resources with strong saline-alkali resistance is an effective means to overcome difficulties utilizing saline-alkali land.This study investigated the salt-tolerance mechanisms and salt-tolerance threshold of Bothriochloa ischaemum cv.‘Taihang’seedlings.Nine NaCl salt stress treatments were set up,and plant height,root length,aboveground biomass and other 13 other plant traits were measured.Salttolerance threshold was calculated by principal component analysis.The results showed that NaCl stress had a greater influence on the growth of the shoots of B.ischaemum seedlings,but the root system was more sensitive to Na+and K+.With increase in both stress exposure time and NaCl concentration,the activities of peroxidase and superoxide dismutase in leaves initially increased and then decreased,and reached their maxima on the 8th and 10th day,respectively,in a treatment of 210 mmol·L^(-1) NaCl.The contents of malondialdehyde and soluble sugar showed an upward trend over time,while chlorophyll content showed a downward trend.After principal component analysis(PCA),the first two sets of PC scores(root length and dry weight)were selected to establish regression relationship.From this evaluation it was found that the dry weight of aboveground parts was the most suitable criterion for evaluating salt tolerance,and the salt tolerance threshold of B.ischaemum seedlings was approximately 207.53 mmol·L^(-1).This study provides preliminary insight about the salt tolerance mechanism of grasses and for planning of subsequent research on the impact of exposure duration and salt concentration on salt tolerance in B.ischaemum.

关 键 词：白羊草 耐盐阈值 生理生化变化 主成分分析 

分 类 号：S543.9[农业科学—作物学]