Mn2+、Pb2+对野生垂穗披碱草种子萌发与幼苗生长的影响

研究了西藏巴青县野生垂穗披碱草种子萌发与幼苗生长对重金属Mn²⁺、Pb²⁺胁迫的生理响应机制,为西藏矿区周边污染土壤和植被修复提供依据。选取西藏巴青县野生垂穗披碱草为试验材料,采用纸上发芽法研究了重金属Mn²⁺、Pb²⁺对其种子萌发和幼苗生长的影响。结果表明,Mn²⁺、Pb²⁺离子胁迫对垂穗披碱草种子萌发和幼苗生长具有极显著的影响(P<0.01);随着Mn²⁺、Pb²⁺浓度的增大,垂穗披碱草种子发芽率、发芽势、发芽指数、活力指数及胚芽长表现为下降的趋势;在200 mg·L^-1 Mn²⁺、Pb²⁺溶液浓度培养下垂穗披碱草种子根较对照略长;随着Mn²⁺、Pb²⁺溶液浓度的升高,垂穗披碱草幼苗叶片叶绿素a和叶绿素b含量持续降低而电导率和MDA含量呈上升趋势。垂穗披碱草对Mn²⁺、Pb²⁺具有一定的耐受性,可适用于Mn²⁺、Pb²⁺轻度污染土壤。

Effects of Mn2+ and Pb2+ on seed germination and seedling growth of Elymus nutans

In order to provide reference for contaminated soil and vegetation restoration in the Tibetan mining area,a study has been undertaken of the physiological response of Elymus nutans' seed germination and seedling growth to heavy metal Mn2+ and Pb2+ stress in Baqing county,Tibet.Select wild E.nutans from the county were used as test materials for investigation using germination methods.The results showed that Mn2+ and Pb2+ ion stress had a significant effect on seed germination and seedling growth.With increasing Mn2+ and Pb2+ concentrations,the germination percentage,germination vigor,germination index,vigor index and bud length of E.nutans showed a declining trend.Under a solution concentration of 200 mg · L-1 Mn2+ and Pb2+,the shoot length of E.nutans was slightly longer than that of the control.With increasing Mn2+ and Pb2+ concentrations,the contents of chlorophyll a and chlorophyll b in leaves decreased while electrical conductivity and malondialdehyde content showed a rising trend.This study suggests that E.nutans has some tolerance to Mn2+ and Pb2+ ion stress that makes it a useful application for soils that are mildly contaminated with these toxins.