摘要
采用基于氨单加氧酶基因(amoA)的荧光定量PCR技术,以黄土高原旱地土为材料,研究长期施肥对土壤氨氧化细菌和氨氧化古菌丰度的影响,并分析环境因素与氨氧化菌丰度的关系。以不施肥土壤为对照(CK),设置3个施肥处理,分别为单施磷肥(P),氮、磷共施(NP)和氮、磷、有机肥共施(NPM)3个处理。结果表明,不同处理氨氧化菌amoA基因拷贝数为1.326×106～1.886×106 g-1,各处理间氨氧化细菌丰度差异不显著;氨氧化古菌的arch-amoA基因拷贝数为1.329×106～4.510×106 g-1,表现为处理NPM>NP>CK>P,NPM处理为对照的3.314倍,二者呈现显著性差异。采用DCCA法对4个处理进行环境相似度分类,结果显示,P和NPM处理、CK和NP处理分别构成了2个相似类群;4个处理和12个环境因子的关联(CCA)分析表明,不同处理中的氨氧化微生物活跃度以及氨氧化过程强度表现为处理NMP>NP>CK>P;不同环境因子和不同施肥处理生境相似度分布存在不同的关系,其中反映氨氧化过程的硝态氮含量、氨氧化细菌和氨氧化古菌丰度,以及代表微生物生长主要环境因素的pH值、含水量、全氮和有机碳含量与不同施肥处理导致的生境相似度的分布关系最为紧密。
Real-time PCR with primers targeting Ammonia monooxygenase subunit A gene （amoA） was performed to quantify abundance of ammonia-oxidizing bacteria （AOB） and ammonia-oxidizing archaea （AOA） in dry highland soil, long-term fertilized, from Loess Plateau. We also investigated the relationship between environmental factors and abundance of ammonia-oxidizing organism. The treat- ments were no fertilizer （CK）, phosphate （P）, nitrogen/phosphate fertilizers （NP）, and NP combined with organic fertilizer （NPM）. We found that fertilization caused no significant difference on the amoA gene copy numbers of AOB arranging from 1. 326×10^6 to 1. 886×10^6 copies ·g-1 dry soil. In contrast, abundance of arch-amoA gene was determined by different fertilizers, with copy numbers from 1. 329X106 to 4. 510×10^6, in an decreasing order as NPM〉NP〉CK〉P, while abundance of arch-amoA gene in NMP was 3. 314 times higher than that of CK, showing significant difference. Detrended canonical correspondence analysis （DCCA） was adopted to class treatments by their environmental similarities, which indicated that P and NPM, CK and NP were presented as two groups respectively; Canonical correspondence analysis （CCA） of 4 treatments and 12 environmental factors verified that the activity of ammonia oxidizer and ammonia oxidation in different fertilizations was ordered as NPM〉NP〉CK〉P. These findings represent that environmental factors reflecting ammonia oxidation like contend of nitrate nitrogen （NO3 -N）, abundance of AOA and AOB, and factors related to microbial growth conditions such as pH, moisture, total nitrogen and organic carbon content determined the environmental similarity ordination of the treatments.
出处
《西北农业学报》
CAS
CSCD
北大核心
2012年第6期41-46,共6页
Acta Agriculturae Boreali-occidentalis Sinica
基金
国家自然科学基金项目资助(40971158)
关键词
旱地土壤
施肥
氨氧化菌
丰度
荧光定量PCR
Dry highland soil
Long-term fertilization
Ammonia-oxidizing organism
Abundance
Real-time PCR
