4个草品种种子发芽及幼苗生长对汞胁迫的响应及汞富集能力  

Effect of Hg Stress on Growth Characteristics and Hg Enrichment Ability of Four Turfgrass and Forage Varieties at Seedling Stage

作　　者：杜建雄 任尉香 李剑峰 张淑卿 周丕飞 DU Jian-xiong;REN Yu-xiang;LI Jian-feng;ZHANG Shu-qing;ZHOU Pi-fei(School of Public Administration,Guizhou University of Finance and Economics,Guizhou Guiyang 550025,China;School of Foreign Languages,Guizhou Normal University,Guizhou Guiyang 550025,China;Institute of Soil and Environment Bioremediation in Karst Habitats,Guizhou Normal College,Guizhou Guiyang 550018,China)

机构地区：[1]贵州财经大学公管学院,贵州贵阳550025 [2]贵州师范大学外国语学院,贵州贵阳550025 [3]贵州师范学院喀斯特生境土壤与环境生物修复研究所,贵州贵阳550018

出　　处：《西南农业学报》2021年第9期1969-1976,共8页Southwest China Journal of Agricultural Sciences

基　　金：贵州省科学技术基金项目“万山废弃汞矿区盛宴黑麦草与其内生菌的协同汞富集机理研究”[黔科合基础-ZK(2021)229];“贵州万山汞矿区生态修复草坪草品种选育及适应性研究”[黔科合J字(2014)2049];贵州省科技计划重点项目[黔科合基础(2020)1Z077];贵州省科技奖励补助项目“酸性富硒土壤茶树解硒促生菌剂制备研究”[黔科合平台人才(2018)5778-05];贵州师范学院一流培育学科建设项目(2019YLPYXKB01)。

摘　　要：【目的】探明不同草坪草及牧草品种种子发芽及幼苗生长对汞胁迫的响应及富集能力,为抗汞胁迫及汞富集力强的草品种选择提供依据。【方法】选取前期通过汞胁迫发芽试验筛选而得的多花黑麦草(Lolium multiflorum Lam.)的盛宴(Feast)、紫羊茅(Festuca rubra L.)的派尼(Pernille)和传奇(Legend)3个草坪草品种及多年生紫花苜蓿(Medicago sativa L.)的金黄后(Golden empress)1个牧草品种为试验材料,以0~180 mg/L 7个Hg^(2+)浓度梯度进行发芽试验,考察4个草品种的种子发芽期对汞的耐受性;再以0~181 mg/kg 5个Hg^(2+)浓度梯度对4个草品种进行土培盆栽试验,考察其苗期生长对汞胁迫的响应及富集能力。【结果】发芽期汞耐受性:随Hg^(2+)浓度升高,4个草品种的发芽率、发芽势、发芽指数、活力指数均不同程度降低,下降幅度因品种存在差异,传奇和派尼的发芽相关指标较金皇后和盛宴的下降幅度大;苗期汞耐受性:随Hg^(2+)浓度升高,4个草品种的出苗率、株高、根长、鲜重、叶面积均不同程度下降,传奇和派尼的生长受抑制程度更大,低浓度Hg^(2+)对金皇后、盛宴和派尼的生长有一定促进作用;4个草品种的汞富集系数随Hg^(2+)浓度升高而明显下降,其中金皇后汞富集能力最强,盛宴和传奇次之,派尼最弱。【结论】4个草品种在不同浓度Hg^(2+)胁迫下,金皇后和盛宴比派尼和传奇受到的伤害程度低,显示出较强的抗汞胁迫能力,同时,金皇后和盛宴具有较好的汞富集能力,可选择为汞污染土壤植物修复的先锋草品种。【Objective】The study aimed to provide the scientific basis for selection of turfgrass and forage varieties with strong resistance to Hg stress and high Hg enrichment ability by probing the effect of Hg stress on germination,growth and Hg enrichment ability of four different turfgrass and forage varieties at seedling stage.【Method】Three turfgrass varieties[Feast(Lolium multiflorum Lam.),Pernille(Festuca rubra L.)and Legend(Festuca rubra L.)]and one forage variety[Golden empress(Medicago sativa L.)]screened from the preliminary germination test under Hg stress are used to investigate their tolerance to Hg at seed germination stage under 7 Hg^(2+) concentrations(0-180 mg/L)and then to discuss their response to Hg stress and Hg enrichment ability at seedling stage by a pot test under 5 Hg^(2+) concentrations(0-181 mg/kg).【Result】The germination rate,germination potential,germination index,vigor index of four tested varieties decrease with increase of Hg^(2+) concentration to varying degrees at germination stage and there is a difference in decrease range among four tested varieties.The decrease range of Pernille and Legend is higher than Golden empress and Feast in relative germination indexes.The emergence rate,height,root length,fresh weight and leaf area of four tested varieties decrease with increase of Hg^(2+) concentration to varying degrees at seedling stage and the growth of Legend and Pernille is significantly inhibited.Low Hg^(2+) concentration has a certain promotion effect on growth of Pernille and Feast.The Hg enrichment coefficient of four tested varieties decreases obviously with increase of Hg^(2+) concentration and the Hg enrichment coefficient of Golden empress is the highest,followed by Feast,Legend and Pernille.【Conclusion】Golden empress and Feast with strong Hg tolerance and better Hg enrichment ability should be selected as pioneer turfgrass varieties for phytoremediation of mercury-contaminated soil.

关 键 词：汞胁迫 草坪草 牧草 发芽率 生物量 汞富集系数 

分 类 号：S812[农业科学—草业科学]