摘要
为探讨Sphingomonas sp.DC-6对玉米根际乙草胺残留的降解作用,本文采用盆钵试验探究Sphingomonas sp.DC-6对玉米乙草胺药害的修复功能。结果表明,Sphingomonas sp.DC-6具有高效降解乙草胺的能力,仅48 h就能完全降解50 mg/L乙草胺。当玉米种植于乙草胺含量不低于1.0 mg/kg(干土)的土壤中,生长受到明显抑制,主要表现为植株矮小和叶片卷曲畸形,接入Sphingomonas sp.DC-6后,玉米植株前期虽生长迟缓,但叶片无畸形,后期生长情况与未受药害处理相近。将Sphingomonas sp.DC-6接种到含1.0 mg/kg乙草胺土壤中,接种3 d,乙草胺降解率为57.14%;接种15 d,乙草胺降解率达到89.29%。接入根际土壤后,Sphingomonas sp.DC-6数量呈下降趋势,前9 d下降速率较快,之后下降幅度明显降低。加药、加降解菌处理较只加降解菌处理下降幅度小,且接种15 d时Sphingomonas sp.DC-6的菌落数平均为245 CFU/g,这表明Sphingomonas sp.DC-6可在玉米根际有效定殖14 d左右。
In order to investigate the effect of Sphingomonas sp.DC-6 on the biodegradation of acetochlor residue in maize rhizosphere,pot experiments were conducted to investigate the repair function of Sphingomonas sp.DC-6 on acetochlor damage in maize.The results showed that Sphingomonas sp.DC-6 had the ability of degrading acetochlor with high efficiency,and it could completely degrade 50 mg/L acetochlor in only 48 h.When maize was planted in soil with acetochlor content not less than 1.0 mg/kg(dry soil),maize growth was significantly inhibited,mainly manifested by plant shortness and leaf crimp malformation.After Sphingomonas sp.DC-6 was added,maize growth was delayed in the early stage,but leaf malformation was not observed,and maize growth was similar to that without drug damage treatment.Sphingomonas sp.DC-6 was inoculated into soil containing 1.0 mg/kg acetochlor for 3 days,and the degradation rate of acetochlor was 57.14%;after inoculation for 15 days,the degradation rate of acetochlor reached 89.29%.The number of Sphingomonas sp.DC-6 in the rhizosphere soil decreased rapidly in the first 9 days,and then the decline decreased significantly;compared with adding degrading bacteria and acetochlor treatment,the decrease rate of adding degrading bacteria was smaller,and the average colony number of Sphingomonas sp.DC-6 was 245 CFU/g at 15 d,which indicated that Sphingomonas sp.DC-6 could effectively colonize to maize rhizosphere for about 14 d.
作者
耿翔
李强
徐铭阳
黄星
GENG Xiang;LI Qiang;XU Mingyang;HUANG Xing(Jiangning District Hushu Street Agricultural Service Center in Nanjing City,Nanjing Jiangsu 211125;College of Life Sciences,Nanjing Agricultural University,Nanjing Jiangsu 210095)
出处
《现代农业科技》
2021年第20期84-88,103,共6页
Modern Agricultural Science and Technology
基金
江苏省农业科技自主创新资金项目(CX〔18〕1005)。
