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微生物固碳在减缓全球气候变化、实现人类可持续发展方面具有重要的意义,通过揭示长期不同施肥制度对土壤固碳细菌的影响规律,可以为我国稻田土壤科学施肥,稻田固碳和温室气体减排的共轭双赢作用提供重要的理论依据。以湖南宁乡国家级稻田肥力变化长期定位试验为平台,采用PCR-克隆测序和实时荧光定量(Real-time)PCR技术,研究不施肥(CK),氮磷钾肥(NPK)和氮磷钾加秸秆还田(NPK plus crop residue return;NPKS)3种长期施肥制度对稻田土壤固碳细菌群落结构及数量的影响。通过分析固碳细菌cbbL基因文库发现,长期施肥导致土壤固碳细菌种群结构产生了明显差异,NPK和NPKS处理中兼性自养固碳菌群落优势增加而严格自养固碳菌生长受到抑制。LUBSHUFF软件统计分析显示cbbL基因文库在CK、NPK及NPKS处理间均存在显著性差异。3种施肥处理的稻田土壤细菌cbbL基因拷贝数为3.35×108—5.61×108/g土,施肥后,土壤细菌cbbL基因数量增加,其中NPKS处理cbbL数量最多,是CK处理的1.5倍左右。稀疏曲线则显示长期施化肥导致细菌cbbL基因多样性高于NPKS,而NPKS高于CK。上述结果表明了长期施肥对土壤固碳细菌群落结构,多样性及数量均有显著的影响。结果可为深入探讨稻田土壤微生物固碳潜力及其影响机理提供有力的依据。
Microbial carbon sequestration plays an important role in alleviating global climate change and achieving human sustainable development. By revealing the effect of long-term different fertilization systems on soil-fixing bacteria, it can be used for scientific fertilization of rice paddy soils, carbon sequestration of rice fields and reduction of greenhouse gases Row of conjugate win-win role provides an important theoretical basis. This study investigated the effects of non-fertilization (CK), NPK and NPK on the long-term fertility changes of Ningxiang National Nature Reserve in Hunan Province using PCR-cloning sequencing and Real-time PCR. Effects of three long - term fertilization systems including NPK plus crop residue return (NPKS) on community structure and quantity of soil - fixing carbon - fixing bacteria in paddy soil. Through the analysis of the cbbL gene library of carbon-fixing bacteria, it was found that the long-term fertilization resulted in significant differences in the population structure of soil-fixing carbon-fixing bacteria. The facultative autotrophic mycelium community increased in NPK and NPKS treatments and the growth of strict autotrophic bacteria was inhibited. Statistical analysis of LUBSHUFF software showed that the cbbL gene library was significantly different between CK, NPK and NPKS treatments. The bacterial cbbL gene copy number was 3.35 × 108-5.61 × 108 / g in paddy soils after fertilization. After fertilization, the amount of cbbL gene in soil bacteria increased. The number of cbbL gene in NPKS was the largest, about 1.5 times that of CK. Sparse curves showed that long-term application of chemical fertilizers resulted in higher bacterial cbbL gene diversity than NPKS, while NPKS was higher than CK. The above results show that long-term fertilization has a significant impact on the community structure, diversity and quantity of soil-fixing carbon-fixing bacteria. The results could provide a strong basis for further study on the potential of carbon sequestration in paddy soils and its influence mechanism.