腐植酸钠对铅、镉胁迫小麦种子萌发及生长的影响

Effects of NaHA Treatments on Wheat Seed Germination and Seedling Growth under Lead and Cadmium Stresses

为研究不同浓度腐植酸钠对主要重金属(铅,镉)胁迫下小麦种子萌发及生长的影响,以小麦品种‘鲁麦21号’为材料,用不同浓度Pb^(2+)溶液、Cd^(2+)溶液处理小麦种子,观察记录不同浓度Pb^(2+)、Cd^(2+)溶液对小麦种子萌发和生长的影响,筛选出Pb^(2+)、Cd^(2+)胁迫浓度,在胁迫浓度下观察不同浓度的腐植酸钠对小麦种子的萌发及生长的影响。研究结果表明:铅、镉胁迫会降低小麦种子的发芽势、发芽率、发芽指数和活力指数,使小麦幼苗的芽和根的生长受到抑制,其中以400 mg/L(Pb^(2+))、100滋mol/L(Cd^(2+))处理最明显。一定浓度的腐植酸钠处理提高了该Pb^(2+)、Cd^(2+)胁迫下小麦种子的发芽率、发芽势、发芽指数和活力指数等指标,促进了小麦幼苗芽和根的生长,部分缓解了铅、镉对小麦种子萌发及幼苗生长的破坏和抑制作用。但随着腐殖酸钠浓度的增大,其对铅、镉胁迫的缓解效应逐渐减弱,甚至与铅、镉起协同作用,反而加重了对小麦的毒害。本研究初步阐明了腐植酸钠对铅镉胁迫下小麦种子萌发及生长的影响,可为重金属污染农田的作物生产活动以及相关基础研究提供一定参考。

In order to study the effects of different concentrations of sodium humate on germination and growth of wheat seeds under heavy metal（lead and cadmium） stress,wheat seeds were treated with different concentrations of Pb2＋ solution and Cd2＋ solution by using the wheat cultivar ＇Lumai 21＇ as test material.The effects of different concentrations of Pb2＋ and Cd2＋ solution on germination and growth of wheat seeds were observed and recorded.The study screened out the Pb2＋ and Cd2＋ stress concentrations,and observed the effects of different concentrations of sodium humate on the germination and growth of wheat seeds under the stress concentration.The results showed that lead and cadmium stresses would reduce the germination force,germination rate,germination index and vigor index of wheat seeds,and inhibit the growth of buds and roots of wheat seedling,in which 400 mg/L Pb2＋ and 100 μmol/L Cd2＋ were the most obvious treatments.Specific concentration of humic acid sodium treatment improved the germination rate,germination potential,germination index and vigor index of wheat seed under Pb2＋ and Cd2＋ stress,and promoted the seedling bud and root growth,which partially alleviated the damage and inhibition of lead and cadmium on seed germination and seedling growth of wheat.But with the increasing concentration of NaHA,the ameliorative effect of Pb and Cd stresses weakened gradually,and even played a synergistic role with lead and cadmium which would significantly increase the toxicity of wheat.The study preliminarily elucidated the effects of sodium humate on seed germination and growth of wheat under Pb and Cd stress,which could provide some reference for crop production activities of heavy metal contaminated farmland and related basic research.