河岸带植物根际苄嘧磺隆降解与微生物学特征

Bensulfuron-methyl Degradation Dynamics and Microbiological Characteristics in Rhizophere Soils with Different Riparian Plants

对芦苇、茭白、菖蒲3种河岸带植物根际苄嘧磺隆降解过程及微生物生态学特征进行研究.结果表明,不同河岸带植物对苄嘧磺隆的根际降解的增强效应存在显著差异,其降解速率大小依次为:菖蒲>芦苇>茭白.培养结束时,菖蒲根际土壤苄嘧磺隆的残留量较芦苇和茭白分别降低了23.1%和32.2%.在苄嘧磺隆作用下,供试3种河岸带植物根际脱氢酶活性表现出先激活后抑制,再恢复的变化趋势,而对脲酶和磷酸酶的影响均表现出抑制效应.苄嘧磺隆施加明显降低了河岸带植物根际土壤微生物的数量,特别是对细菌和真菌的数量的影响更为明显.与芦苇和茭白相比,菖蒲根际土壤具有更高的酶活性和微生物数量,说明该植物根际土壤中微生物对苄嘧磺隆污染具有较好的缓冲作用,从而大大增强了苄嘧磺隆生物降解效应.

The paper presents a research on the degradation of bensulfuron-methyl and microbial characteristics in rhizophere soils with different riparian plants.The research results show that there exist significant differences in microbial degradation dynamics of bensulfuron-methyl in the rhizophere soils among three kinds of riparian plants.Acorus calamus shows a significantly higher degradation efficiency of bensulfuron-methyl in the rhizophere soils,Zizania aquatica cames the second and Phragmites australis the last one.Residual bensulfuron-methyl content in Acorus calamus rhizophere soil is 23.1% and 32.2% lower than that in Zizania aquatic and Phragmites australis rhizophere soils,respectively.Due to bensulfuron-methyl addition,the activities of the dehydrogenase are stimulated firstly,and then are inhibited,and finally recovered to the initial level,while the activities of the phosphatase and urease show a significantly decreasing trend.Bensulfuron-methyl addition significantly decreases microbial numbers in the rhizophere,especially for bacteria and fungi.Acorus calamus shows significantly higher enzyme activities and larger microbial numbers in the rhizophere soils,as compared to Zizania aquatica and Phragmites australis,which means that Acorus calamus has a better buffer performance to bensulfuron-methyl addition,and a greater improvement effect on microbial degradation of bensulfuron-methyl in the rhizophere soils.