The diversification of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) communities and their potential nitrification activity (PNA) on a large scale have not been well documented. In this work, se...The diversification of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) communities and their potential nitrification activity (PNA) on a large scale have not been well documented. In this work, seven paddy soils from different geographic regions in Sichuan, P. R. China were selected to determine the spatial distribution of the activities, abundances and community compositions of AOB and AOA. PNA varied greatly among paddy soils, and was positively correlated with soil pH (P< 0.05). The abundance of AOA was 81.1 to 1 670.0 times more than that of AOB, which indicates paddy soil environments favor the growth of AOA. Denaturing gradient gel electrophoresis fingerprints of amoA genes exhibited distinct spatial differences in AOA compositions rather than in AOB compositions. Sequencing analysis revealed that acidic soils were dominated by AOA within marine group 1.1 a-associated lineage, whereas the soil group 1.1b lineage AOA predominated in neutral and alkaline soils. Both nitrosopira cluster 3-like and Nitrosomonas cluster 7-like AOB dominated the AOB communities in the paddy soils. Redundancy analysis suggested that soil NH4^+-N content was the most significant driver determining the AOB community structure, while no significant correlation between AOA community structure and soil properties was found. The findings highlight that the activity and composition of ammonia oxidizers exhibit spatial variations in complex paddy fields due to the joint influence of soil variables associated with pH and N availability.展开更多
【目的】研究不同盐度灌溉水对棉田土壤氨氧化细菌及酶的影响。【方法】试验设置三个灌溉水盐度(电导率EC):0.35(淡水)、4.61(微咸水)和8.04 d S/m(咸水),分别以FW、BW和SW表示。【结果】咸水、微咸水灌溉显著增加土壤盐度,土壤中铵态...【目的】研究不同盐度灌溉水对棉田土壤氨氧化细菌及酶的影响。【方法】试验设置三个灌溉水盐度(电导率EC):0.35(淡水)、4.61(微咸水)和8.04 d S/m(咸水),分别以FW、BW和SW表示。【结果】咸水、微咸水灌溉显著增加土壤盐度,土壤中铵态氮显著增加,硝态氮显著降低;微咸水和淡水灌溉处理土壤潜在硝化势无显著差异,但是咸水灌溉处理显著降低了土壤潜在硝化势;微咸水处理土壤氨氧化细菌数量与淡水处理差异不显著,但是咸水灌溉处理氨氧化细菌数量较淡水处理降低了59.38%;不同灌溉水盐度对土壤硝酸还原酶和亚硝酸还原酶影响相似,随着灌溉水盐度的增加,土壤硝酸还原酶和亚硝酸还原酶活性显著降低。盐分对羟胺还原酶活性影响不大。【结论】适宜盐度的微咸水滴灌对土壤氨氧化细菌和潜在硝化势无显著影响,但高盐度的咸水灌溉会导致氨氧化细菌数量减少,潜在硝化势和关键酶活性降低,直接影响硝化/反硝化作用。展开更多
冬闲田种植绿肥是传统的水稻土培肥增产措施,但绿肥-水稻种植系统中,不同绿肥种类对硝化作用的影响规律及调控机制尚不明确。采用盆栽试验,研究了冬种紫云英、油菜、黑麦草对土壤性状及硝化作用的影响,并通过特异性细菌抑制剂(卡那霉素...冬闲田种植绿肥是传统的水稻土培肥增产措施,但绿肥-水稻种植系统中,不同绿肥种类对硝化作用的影响规律及调控机制尚不明确。采用盆栽试验,研究了冬种紫云英、油菜、黑麦草对土壤性状及硝化作用的影响,并通过特异性细菌抑制剂(卡那霉素和大观霉素)研究了氨氧化细菌(AOB)和氨氧化古菌(AOA)对硝化作用的相对贡献。结果表明,冬种三种绿肥均显著降低了早稻移栽前、分蘖期和拔节期的硝化潜势,同时增加了多数取样时期的铵态氮含量,降低了硝态氮含量,硝态氮含量与硝化潜势显著正相关。与冬季休闲相比,绿肥处理提高了大部分时期的AOA和AOB amo A基因丰度。同时,AOB在水稻主要生长期土壤硝化过程中均占主导地位,相对贡献约为61.02%~82.37%。不同绿肥处理在早稻分蘖期促进了AOB对硝化作用的相对贡献,在早稻移栽前和拔节期降低了AOA的相对贡献。综上,绿肥可降低稻田土壤中的硝态氮淋失风险,冬种绿肥在稻田土壤氮素管理中有重要意义。展开更多
基金Funded by the National Natural Science Foundation of China (No.41606142)the Fundamental Research Funds of China West Normal University (No.463140 and No.412554)
文摘The diversification of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) communities and their potential nitrification activity (PNA) on a large scale have not been well documented. In this work, seven paddy soils from different geographic regions in Sichuan, P. R. China were selected to determine the spatial distribution of the activities, abundances and community compositions of AOB and AOA. PNA varied greatly among paddy soils, and was positively correlated with soil pH (P< 0.05). The abundance of AOA was 81.1 to 1 670.0 times more than that of AOB, which indicates paddy soil environments favor the growth of AOA. Denaturing gradient gel electrophoresis fingerprints of amoA genes exhibited distinct spatial differences in AOA compositions rather than in AOB compositions. Sequencing analysis revealed that acidic soils were dominated by AOA within marine group 1.1 a-associated lineage, whereas the soil group 1.1b lineage AOA predominated in neutral and alkaline soils. Both nitrosopira cluster 3-like and Nitrosomonas cluster 7-like AOB dominated the AOB communities in the paddy soils. Redundancy analysis suggested that soil NH4^+-N content was the most significant driver determining the AOB community structure, while no significant correlation between AOA community structure and soil properties was found. The findings highlight that the activity and composition of ammonia oxidizers exhibit spatial variations in complex paddy fields due to the joint influence of soil variables associated with pH and N availability.
文摘【目的】研究不同盐度灌溉水对棉田土壤氨氧化细菌及酶的影响。【方法】试验设置三个灌溉水盐度(电导率EC):0.35(淡水)、4.61(微咸水)和8.04 d S/m(咸水),分别以FW、BW和SW表示。【结果】咸水、微咸水灌溉显著增加土壤盐度,土壤中铵态氮显著增加,硝态氮显著降低;微咸水和淡水灌溉处理土壤潜在硝化势无显著差异,但是咸水灌溉处理显著降低了土壤潜在硝化势;微咸水处理土壤氨氧化细菌数量与淡水处理差异不显著,但是咸水灌溉处理氨氧化细菌数量较淡水处理降低了59.38%;不同灌溉水盐度对土壤硝酸还原酶和亚硝酸还原酶影响相似,随着灌溉水盐度的增加,土壤硝酸还原酶和亚硝酸还原酶活性显著降低。盐分对羟胺还原酶活性影响不大。【结论】适宜盐度的微咸水滴灌对土壤氨氧化细菌和潜在硝化势无显著影响,但高盐度的咸水灌溉会导致氨氧化细菌数量减少,潜在硝化势和关键酶活性降低,直接影响硝化/反硝化作用。
文摘冬闲田种植绿肥是传统的水稻土培肥增产措施,但绿肥-水稻种植系统中,不同绿肥种类对硝化作用的影响规律及调控机制尚不明确。采用盆栽试验,研究了冬种紫云英、油菜、黑麦草对土壤性状及硝化作用的影响,并通过特异性细菌抑制剂(卡那霉素和大观霉素)研究了氨氧化细菌(AOB)和氨氧化古菌(AOA)对硝化作用的相对贡献。结果表明,冬种三种绿肥均显著降低了早稻移栽前、分蘖期和拔节期的硝化潜势,同时增加了多数取样时期的铵态氮含量,降低了硝态氮含量,硝态氮含量与硝化潜势显著正相关。与冬季休闲相比,绿肥处理提高了大部分时期的AOA和AOB amo A基因丰度。同时,AOB在水稻主要生长期土壤硝化过程中均占主导地位,相对贡献约为61.02%~82.37%。不同绿肥处理在早稻分蘖期促进了AOB对硝化作用的相对贡献,在早稻移栽前和拔节期降低了AOA的相对贡献。综上,绿肥可降低稻田土壤中的硝态氮淋失风险,冬种绿肥在稻田土壤氮素管理中有重要意义。
