This research was conducted to study the influence of NaHCO3and fertilizer treatments on flooded soils tothe chemistry of soil and rice plant growth.The experiment was done in a greenhouse using a split-split plot des...This research was conducted to study the influence of NaHCO3and fertilizer treatments on flooded soils tothe chemistry of soil and rice plant growth.The experiment was done in a greenhouse using a split-split plot design ofthree factors: two types of soil,three doses of fertilizers and three levels of NaHCO3with three replications.The firstfactor was two kind of soils Fluvaquent and Calciquert,the factor was without nutrient(blank),macro nutrients,andcompletely nutrients(second macro and micro nutrients),and the third factor was 0 mg/kg,200 mg/kg and 400 mg/kgof NaHCO3or equivalent with 0 mg,1 200 mg and 2 400 mg NaHCO3per pot.Each experimental unit used a pot of 10L capacity and filled with soil mud equivalent with 6 kg of dried soil.After each of treatment combination mixed into themud soil,two plants of IR-32 variety were grown,and flooded at5 cm high accordingly with growth period.Parametersobserved were the growth of tillers,electrical conductivity(E.C.) and pH.The experiment results showed that the treatment of NaHCO3increased the soluble salt content(E.C.) and soilacidity(pH) during flooding on Calciquerts and Fluvaquents.The content of soluble salt decreased to 2.0 mmhos/cm,while pHon Calciquert decreased towards the neutral pH.Anyhowthe pHon Fluvaquents increased approach to neutral.The treatments of NaHCO3inhibited the tiller growth,either macro fertilizer and completely fertilizer increased thetillers,but did not improve the negative effect of alkalinity due to of NaHCOtreatment.展开更多
从油水淹地污染土壤中获得26株石油降解菌,筛选出表面活性剂产生菌1株(H-6)和优势菌6株(H-1、H-17、H-18、H-19、H-20、H-23),结合菌株形态观察、革兰氏染色和16S r DNA序列同源性分析,鉴定表面活性剂产生菌H-6为堀越氏芽孢杆菌(Bacillu...从油水淹地污染土壤中获得26株石油降解菌,筛选出表面活性剂产生菌1株(H-6)和优势菌6株(H-1、H-17、H-18、H-19、H-20、H-23),结合菌株形态观察、革兰氏染色和16S r DNA序列同源性分析,鉴定表面活性剂产生菌H-6为堀越氏芽孢杆菌(Bacillus horikoshii)。以表面活性剂产生菌H-6为中心,再任选3株优势菌株构建石油降解菌群,得到高效石油降解菌群C5(H-1、H-6、H-18、H-19),通过正交试验得到菌群C5各菌种的最佳接种量。结果表明:接种量15%(H-1)、15%(H-6)、20%(H-18)、10%(H-19),温度25℃,石油含量2 000 mg/L条件下,7 d时石油降解率达到78.87%。这说明高效降解菌群C5对石油具有较好的降解效果,可应用于油水淹地污染土壤的修复。展开更多
Objective To investigate the potential effects of herbicide quinclorac (3,7-dichloro-8-quinoline-carboxylic) on the culturable microorganisms in flooded paddy soil. Methods Total soil aerobic bacteria, actinomycetes a...Objective To investigate the potential effects of herbicide quinclorac (3,7-dichloro-8-quinoline-carboxylic) on the culturable microorganisms in flooded paddy soil. Methods Total soil aerobic bacteria, actinomycetes and fungi were counted by a 10-fold serial dilution plate technique. Numbers of anaerobic fermentative bacteria (AFB), denitrifying bacteria (DNB) and hydrogen-producing acetogenic bacteria (HPAB) were numerated by three-tube anaerobic most-probable-number (MPN) methods with anaerobic liquid enrichment media. The number of methanogenic bacteria (MB) and nitrogen-fixing bacteria (NFB) was determined by the rolling tube method in triplicate. Soil respiration was monitored by a 102G-type gas chromatography with a stainless steel column filled with GDX-104 and a thermal conductivity detector. Results Quinclorac concentration was an important factor affecting the populations of various culturable microorganisms. There were some significant differences in the aerobic heterotrophic bacteria. AFB and DNB between soils were supplemented with quinclorac and non-quinclorac at the early stage of incubation, but none of them was persistent. The number of fungi and DNB was increased in soil samples treated by lower than 1.33μg·g-1 dried soil, while the CFU of fungi and HPAB was inhibited in soil samples treated by higher than 1.33μg·g-1 dried soil. The population of actinomycete declined in negative proportion to the concentrations of quinclorac applied after 4 days. However, application of quinclorac greatly stimulated the growth of AFB and NFB. MB was more sensitive to quinclorac than the others, and the three soil samples with concentrations higher than 1 μg·g-1 dried soil declined significantly to less than 40% of that in the control, but the number of samples with lower concentrations of quinclorac was nearly equal to that in the control at the end of experiments. Conclusion Quinclorac is safe to the soil microorganisms when applied at normal concentrations (0.67μg·g-1).展开更多
基金the Directorat of High Education,Dept.of National Education of the Republic of Indonesia
文摘This research was conducted to study the influence of NaHCO3and fertilizer treatments on flooded soils tothe chemistry of soil and rice plant growth.The experiment was done in a greenhouse using a split-split plot design ofthree factors: two types of soil,three doses of fertilizers and three levels of NaHCO3with three replications.The firstfactor was two kind of soils Fluvaquent and Calciquert,the factor was without nutrient(blank),macro nutrients,andcompletely nutrients(second macro and micro nutrients),and the third factor was 0 mg/kg,200 mg/kg and 400 mg/kgof NaHCO3or equivalent with 0 mg,1 200 mg and 2 400 mg NaHCO3per pot.Each experimental unit used a pot of 10L capacity and filled with soil mud equivalent with 6 kg of dried soil.After each of treatment combination mixed into themud soil,two plants of IR-32 variety were grown,and flooded at5 cm high accordingly with growth period.Parametersobserved were the growth of tillers,electrical conductivity(E.C.) and pH.The experiment results showed that the treatment of NaHCO3increased the soluble salt content(E.C.) and soilacidity(pH) during flooding on Calciquerts and Fluvaquents.The content of soluble salt decreased to 2.0 mmhos/cm,while pHon Calciquert decreased towards the neutral pH.Anyhowthe pHon Fluvaquents increased approach to neutral.The treatments of NaHCO3inhibited the tiller growth,either macro fertilizer and completely fertilizer increased thetillers,but did not improve the negative effect of alkalinity due to of NaHCOtreatment.
文摘【目的】利用环境转录组技术,研究复杂稻田土壤中微生物群落主要生理代谢过程的基因表达水平及其对长期施氮磷钾肥(Mineral nitrogen,phosphorus,and potassium,NPK)的响应规律。【方法】针对中国科学院常熟农田生态系统长期定位试验的NPK施肥处理和不施肥对照处理(Control check,CK)稻田土壤,淹水培养2周后提取土壤微生物总RNA进行高通量转录组测序,利用MG-RAST网络分析平台(Metagenomics Analysis Server)进行活性微生物组成分析、基因功能注释及基因功能分类。【结果】细菌是CK和NPK处理稻田土壤微生物的优势类群,占比高达95%以上,细菌中的活性基因主要源于变形菌门(Proteobacteria,占细菌的50%以上)。同时也检测到古菌、真核生物和病毒等多种微生物的活性基因,而古菌中的活性基因主要源于奇古菌门(Thaumarchaeota,约占古菌的70%)。酸杆菌门(Acidobacteria)在NPK处理土壤中的转录活性显著高于CK处理土壤,而其他的细菌及古菌类群的转录活性在CK和NPK处理土壤间无显著性差异。CK和NPK处理土壤中表达量最高的基因是ABC transporter编码基因,与物质跨膜运输紧密相关。基于COG(Clusters of Orthologous Genes)、Subsystem、KEGG(Kyoto Encyclopedia of Genes and Genomes)3种基因功能分类数据库,发现CK和NPK处理土壤中微生物的主要代谢活动均为能量产生与转化、碳水化合物代谢、蛋白代谢和氨基酸代谢,而最活跃的代谢路径为氧化磷酸化及氨酰-tRNA合成。【结论】淹水状态下CK和NPK处理稻田土壤中的活性微生物组成较为一致,仅Acidobacteria的转录活性在两者间差异较大;在微生物的主要代谢活动方面,CK和NPK处理土壤之间基本一致,均以能量获取与蛋白代谢为主,长期施用无机化肥对复杂土壤微生物群落水平的主要代谢活动影响较小。
基金This work was supported by the National 863 Programm of China "Bioengineering Technique Project 2002A2104101
文摘Objective To investigate the potential effects of herbicide quinclorac (3,7-dichloro-8-quinoline-carboxylic) on the culturable microorganisms in flooded paddy soil. Methods Total soil aerobic bacteria, actinomycetes and fungi were counted by a 10-fold serial dilution plate technique. Numbers of anaerobic fermentative bacteria (AFB), denitrifying bacteria (DNB) and hydrogen-producing acetogenic bacteria (HPAB) were numerated by three-tube anaerobic most-probable-number (MPN) methods with anaerobic liquid enrichment media. The number of methanogenic bacteria (MB) and nitrogen-fixing bacteria (NFB) was determined by the rolling tube method in triplicate. Soil respiration was monitored by a 102G-type gas chromatography with a stainless steel column filled with GDX-104 and a thermal conductivity detector. Results Quinclorac concentration was an important factor affecting the populations of various culturable microorganisms. There were some significant differences in the aerobic heterotrophic bacteria. AFB and DNB between soils were supplemented with quinclorac and non-quinclorac at the early stage of incubation, but none of them was persistent. The number of fungi and DNB was increased in soil samples treated by lower than 1.33μg·g-1 dried soil, while the CFU of fungi and HPAB was inhibited in soil samples treated by higher than 1.33μg·g-1 dried soil. The population of actinomycete declined in negative proportion to the concentrations of quinclorac applied after 4 days. However, application of quinclorac greatly stimulated the growth of AFB and NFB. MB was more sensitive to quinclorac than the others, and the three soil samples with concentrations higher than 1 μg·g-1 dried soil declined significantly to less than 40% of that in the control, but the number of samples with lower concentrations of quinclorac was nearly equal to that in the control at the end of experiments. Conclusion Quinclorac is safe to the soil microorganisms when applied at normal concentrations (0.67μg·g-1).
