以常规旋耕无秸秆还田(对照)、1年秸秆深翻还田、2年秸秆深翻还田土壤总DNA为模板,采用氨氧化细菌(Ammonia-oxidizing bacteria,AOB)的氨单加氧酶α亚基(amo A)基因特异性引物扩增AOB amo A基因,构建amo A基因文库。运用BLAST程序进行...以常规旋耕无秸秆还田(对照)、1年秸秆深翻还田、2年秸秆深翻还田土壤总DNA为模板,采用氨氧化细菌(Ammonia-oxidizing bacteria,AOB)的氨单加氧酶α亚基(amo A)基因特异性引物扩增AOB amo A基因,构建amo A基因文库。运用BLAST程序进行序列比较发现,玉米秸秆深翻还田土壤中分布有亚硝化弧菌属(Nitrosovibrio)、亚硝化螺菌属(Nitrosospira)和亚硝化单胞菌属(Nitrosomonas)微生物菌群,秸秆深翻还田土壤AOB amo A基因序列主要与保护性耕作、长期施肥、间作、温室和植被恢复土壤中的amo A基因序列相似;常规旋耕无秸秆还田土壤AOB amo A基因序列主要与秸秆焚烧大田土壤和内蒙古草原土的amo A基因序列相似。玉米秸秆深翻还田2年处理(SF-Ⅱ)AOB amo A基因多样性指数最高,其次是玉米秸秆深翻还田1年处理(SF-I),常规旋耕无秸秆还田(CK)最低。展开更多
The application of butachlor as an herbicide in paddy fields is widely practiced,aiming to increase rice yield by directly or indirectly influencing the paddy environment.Periphytic biofilms,which form at the soil-wat...The application of butachlor as an herbicide in paddy fields is widely practiced,aiming to increase rice yield by directly or indirectly influencing the paddy environment.Periphytic biofilms,which form at the soil-water interface in paddy fields,are complex bioaggregates that play an important role in nitrogen (N) cycling.The objective of this study was to investigate the effect of butachlor on periphytic biofilm growth and N cycling under both light and dark conditions in the laboratory.The results revealed that butachlor application hindered the growth of periphytic biofilms and led to the dominance of Cyanobacteria as the primary prokaryotes,while inhibiting the development of eukaryotic Trebouxiophyceae.Furthermore,the application of butachlor reduced the richness and diversity of prokaryotes,but increased those of eukaryotes in periphytic biofilms.The light treatments exhibited higher total N loss because light favored periphytic biofilm growth and enhanced ammonium (NH_(4)^(+)) assimilation and nitrification.Additionally,butachlor application resulted in the increased retention of NH_(4)^(+)-N and nitrate (NO_(3)^(-))-N and an increase in N loss via denitrification.The abundances of functional genes encoding enzymes such as ammonia monooxygenase,nitrite reductase,and nitrous oxide reductase were increased by butachlor application,favoring nitrification and denitrification processes.Overall,the results suggest that butachlor application leads to an increase in total N loss mainly through denitrification in paddy systems,particularly in the presence of periphytic biofilms.Thus,the results may provide valuable insights into the changes in periphytic biofilm growth and N cycling induced by butachlor,and future studies can further explore the potential implications of these changes in paddy soils.展开更多
文摘以常规旋耕无秸秆还田(对照)、1年秸秆深翻还田、2年秸秆深翻还田土壤总DNA为模板,采用氨氧化细菌(Ammonia-oxidizing bacteria,AOB)的氨单加氧酶α亚基(amo A)基因特异性引物扩增AOB amo A基因,构建amo A基因文库。运用BLAST程序进行序列比较发现,玉米秸秆深翻还田土壤中分布有亚硝化弧菌属(Nitrosovibrio)、亚硝化螺菌属(Nitrosospira)和亚硝化单胞菌属(Nitrosomonas)微生物菌群,秸秆深翻还田土壤AOB amo A基因序列主要与保护性耕作、长期施肥、间作、温室和植被恢复土壤中的amo A基因序列相似;常规旋耕无秸秆还田土壤AOB amo A基因序列主要与秸秆焚烧大田土壤和内蒙古草原土的amo A基因序列相似。玉米秸秆深翻还田2年处理(SF-Ⅱ)AOB amo A基因多样性指数最高,其次是玉米秸秆深翻还田1年处理(SF-I),常规旋耕无秸秆还田(CK)最低。
基金supported by the State Key Development Program for Basic Research of China(No.2015CB158200)。
文摘The application of butachlor as an herbicide in paddy fields is widely practiced,aiming to increase rice yield by directly or indirectly influencing the paddy environment.Periphytic biofilms,which form at the soil-water interface in paddy fields,are complex bioaggregates that play an important role in nitrogen (N) cycling.The objective of this study was to investigate the effect of butachlor on periphytic biofilm growth and N cycling under both light and dark conditions in the laboratory.The results revealed that butachlor application hindered the growth of periphytic biofilms and led to the dominance of Cyanobacteria as the primary prokaryotes,while inhibiting the development of eukaryotic Trebouxiophyceae.Furthermore,the application of butachlor reduced the richness and diversity of prokaryotes,but increased those of eukaryotes in periphytic biofilms.The light treatments exhibited higher total N loss because light favored periphytic biofilm growth and enhanced ammonium (NH_(4)^(+)) assimilation and nitrification.Additionally,butachlor application resulted in the increased retention of NH_(4)^(+)-N and nitrate (NO_(3)^(-))-N and an increase in N loss via denitrification.The abundances of functional genes encoding enzymes such as ammonia monooxygenase,nitrite reductase,and nitrous oxide reductase were increased by butachlor application,favoring nitrification and denitrification processes.Overall,the results suggest that butachlor application leads to an increase in total N loss mainly through denitrification in paddy systems,particularly in the presence of periphytic biofilms.Thus,the results may provide valuable insights into the changes in periphytic biofilm growth and N cycling induced by butachlor,and future studies can further explore the potential implications of these changes in paddy soils.
