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以中国科学院桃源农业生态试验站水稻长期定位试验为平台(28°55′49.8″N,111°26′25.7″E),运用PCR、克隆文库构建等分子生物学技术研究长期单施氮肥(尿素)对亚硝化基因(amoA和hao)多样性及其群落结构的影响.结果表明,长期单施氮肥使amoA基因多样性降低(Shannon指数减少了11%),而hao基因多样性几乎不受影响,对amoA优势基因型的影响大于对hao基因的影响;长期施用氮肥使amoA和hao基因的菌群组成分别发生了显著性(p=0.02)和极显著性变化(p=0.002).系统发育分析表明amoA基因主要与未经培养的氨氧化细菌基因相似,相似率主要集中在86%～99%,可能主要来自亚硝化螺菌属;而hao基因主要与Silicibacteria、亚硝化螺菌属(Nitrosospira)和甲基球菌属(Methylococcus)相似,相似率在66%～80%,长期施用氮肥使hao基因主要集中在α-Proteobacteria纲且与Silicibacteria有较近的亲缘关系.总体来说,长期单施氮肥使水稻土中亚硝化基因amoA的多样性降低,使amoA与hao的群落组成发生显著变化.
A long-term single application of nitrogen fertilizer (Urea-N fertilizers) was studied by means of PCR and cloning library construction based on the platform of long-term rice experiment at Taoyuan Agro-Ecological Experimental Station of Chinese Academy of Sciences (28 ° 55’49.8 “N, 111 ° 26’25.7” E) ) On the diversity and community structure of nitrosylated genes (amoA and hao) .The results showed that the long-term single application of nitrogen fertilizer reduced the amoA gene diversity (Shannon index decreased by 11%), while the hao gene diversity was hardly affected , And the effect on amoA dominant genotype was greater than that on hao gene. The long-term application of nitrogen fertilizer caused a significant (p = 0.02) and extremely significant change (p = 0.002) in the bacterial composition of amoA and hao genes, respectively The analysis showed that the amoA gene was mainly similar to the uncultured ammoxidase gene. The similarities were mainly from 86% to 99%, probably from the genus Nitrosospira. The hao gene was mainly related to Silicibacteria, Nitrosospira ) Is similar to Methylococcus with similarity rates ranging from 66% to 80%. Long-term application of nitrogen fertilizes the hao gene in α-Proteobacteria and has a close genetic relationship with Silicibacteria.In general, nitrogen The Central Asian paddy soil nitrification genetic diversity amoA reduced, and the community amoA hao composition changed significantly.