百草枯与草甘膦对蕨类植物的控制作用

蕨类是一种具有特殊生理机能的植物,作为杂草很难治理。选用蕨类植物满江红作为指示植物,以测定灭生性除草剂百草枯和草甘膦对蕨类植物的控制效果。结果表明该植物对草甘膦和百草枯反应灵敏,其中草甘膦对其作用的最佳观察时间为3～7d,百草枯对其作用的最佳观察时间为1～2d。以红盖鳞毛蕨和绒紫萁为指示植物进行田间试验,结果表明百草枯和草甘膦对这些蕨类植物都可以起到很好的防除作用,但反应时间和表现症状有差异。

Arsenic Bioremediation Potential of Arsenite-Oxidizing Micrococcus sp. KUMAs15 Isolated from Contaminated Soil

Environmental arsenic(As) contamination,considered as the largest mass poisoning of the human population,has become a serious health concern for the people of South East Asia,including those living in the Bengal delta.An As-resistant strain,KUMAs15,was isolated from the As-contaminated fields in Nadia Ddistrict in West Bengal,India and was evaluated for its possible use in environmental As bioremediation.Molecular identification based on 16S rDNA gene sequencing revealed that the strain belonged to the genus Micrococcus.The strain tolerated high levels of As and oxidized arsenite under the culture condition.The strain also accumulated large quantities of As when exposed to a wide range of environmentally relevant concentrations of inorganic As.Analysis of the aoxB,arsB,and arsC gene expression explained the underlying cause of arsenite oxidation and As accumulation by KUMAs15.The As-resistant strain KUMAs15 of Micrococcus sp.was suggested to be a potential environmental As decontaminant.

万顺铅锌矿区蜈蚣草内生细菌砷氧化基因(aox B)的多样性分析

【背景】近年来,由于金属矿的开采和冶炼、砷产品的加工与使用、煤的燃烧等各种因素,导致土壤环境中的砷污染越来越严重,导致许多人暴露于极度危险的砷毒毒害之下。【目的】研究四川的万顺铅锌矿区蜈蚣草根组织内生细菌aoxB基因的多样性,为提高土壤重金属污染生态修复效率提供理论依据。【方法】利用实时荧光定量PCR (Real-time quantitative PCR,qPCR)和限制性片段长度多态性(Restriction fragment length polymorphism,RFLP)技术,对四川省汉源县万顺铅锌矿区蜈蚣草根组织内生细菌aoxB基因表达量及多样性进行研究。【结果】qPCR结果表明,不同采样点间的蜈蚣草根组织内生细菌aoxB基因表达量存在明显差异,表现为选矿区>进山口>弃渣场>尾矿区>矿口。酶切图谱结果表明,不同采样点蜈蚣草根组织内生细菌aoxB基因多样性存在明显差异,多样性指数表现为尾矿>矿口>弃渣场>进山口>选矿区。Pearson相关分析显示,aoxB基因的表达量与重金属As之间呈显著负相关(P<0.05),多样性指数则与重金属Pb和As之间呈极显著正相关(P<0.01)。系统发育分析显示,aoxB基因的优势菌群为α-变形菌门(Alphaproteobacteria)。【结论】蜈蚣草根组织中存在丰富的含aoxB基因内生细菌种群,这些内生细菌表现出潜在的应用价值。