【摘要】 稻田施用的除草剂可能会污染邻近水域,对非靶标水生植物产生影响。国家二级重点保护野生植物粗梗水蕨(Ceratopteris pteridoides)主要分布于稻田及其周围水域,其有性繁殖敏感阶段与除草剂施用时间一致,配子体易暴露在除草剂污染中。为了评价除草剂污染对水生态环境特别是对非靶标国家重点保护野生水生植物的影响,保护生物多样性和水生生态环境,该文研究了除草剂苄嘧磺隆(Bensulfuron-methyl)对粗梗水蕨配子体生长和性器官分化的影响。结果表明,苄嘧磺隆对粗梗水蕨孢子萌发没有影响,但对其配子体生长有抑制作用。苄嘧磺隆浓度和粗梗水蕨配子体面积呈明显的剂量-效应关系,苄嘧磺隆对粗梗水蕨配子体生长抑制的EC50(半数效应浓度)为0.086μg·L-1,低于已报道的环境背景浓度。随着苄嘧磺隆浓度升高,粗梗水蕨的雌雄同体配子体逐渐减少,且配子体上颈卵器形成时间推迟。在苄嘧磺隆为10μg·L-1时,粗梗水蕨没有雌雄同体配子体形成。以上研究结果表明,低浓度苄嘧磺隆可抑制粗梗水蕨配子体的生长并影响其性器官的分化,使粗梗水蕨有性繁殖能力减弱。更多还原

【Abstract】 Aims Herbicides applied to rice fields may contaminate nearby aquatic systems through a variety of mechanisms,including drift,surface runoff and leaching,and may have adverse effects on non-target aquatic plants that play a major role in the aquatic ecosystem.The second category of the key protected wild plant,Ceratopteris pteridoides,is frequently observed in paddy fields and adjacent lakes and ponds.Its sexual reproduction phase coincides with herbicide application;therefore,its gametophytes are likely exposed to rice herbicides.The objective of this study is to assess the ecological hazard of herbicide contamination on this aquatic plant.Methods We cultured spores of C.pteridoides in aqueous solutions of different bensulfuron-methyl concentrations and observed gametophyte growth and sex organ differentiation.Important findings Bensulfuron-methyl had no effect on spore germination of C.pteridoides.However,it inhibited gametophyte growth with the EC50 of 0.086 μg·L-1,which was below the reported environment concentration.Bensulfuron-methyl reduced the ratio of hermaphrodite gametophyte and delayed archegonium differentiation of C.pteridoides with the increase in concentration.When bensulfuron-methyl concentration was 10 μg·L-1,gametophytes ceased growth and did not form archegonia.Therefore,bensulfuron-methyl inhibits gametophyte growth and sex organ differentiation of C.pteridoides at low concentration and may pose a risk to sexual reproduction of C.pteridoides in the field.更多还原