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依托长沙农业环境观测研究站不同施肥方式长期定位试验,直接从土壤中抽提总DNA和RNA,应用T-RFLP和RTPCR技术在DNA和c DNA水平对比研究施肥对亚热带稻田土壤细菌丰度和群落结构的影响.结果表明,施肥和秸秆还田显著改变了土壤细菌群落组成(DNA水平)和转录组成(c DNA水平)结构,且不同处理中DNA水平的T-RFLP图谱与cDNA水平相差很大.施肥和秸秆还田降低了土壤中存在的细菌多样性,对土壤中转录的细菌多样性没有影响.土壤16S rRNA基因丰度(DNA水平)平均是其转录丰度(c DNA水平)的337倍,与不施氮肥处理(N0)相比,平衡施肥(NPK)没有改变土壤细菌的数量,在平衡施肥的基础上进行秸秆还田增加了土壤细菌的数量,但高量与低量秸秆还田没有显著差异.RDA分析表明,稻田土壤中铵态氮含量是调控各处理土壤中存在及转录的细菌群落的关键因子.总体而言,不管在DNA还是c DNA水平,研究施肥对土壤细菌丰度的影响均是可行并可信的;但只有在c DNA水平开展研究,才能有效发现细菌群落对环境的适应性.
Relying on long-term experiment with different fertilization methods at Changsha Agricultural Environment Observation Station, the total DNA and RNA were directly extracted from the soil. T-RFLP and RTPCR techniques were used to study the relationship between the bacterial abundance and community The results showed that fertilization and straw addition significantly changed the composition of soil bacterial community (DNA level) and transcriptional component (c DNA level), and the DNA level of T-RFLP in different treatments differed greatly from the cDNA level Fertilization and straw addition reduced bacterial diversity in the soil and had no effect on the bacterial diversity transcribed in the soil. The average abundance (DNA level) of soil 16S rRNA gene was 337 (c DNA level) Compared with no nitrogen fertilizer (N0), balanced fertilization (NPK) did not change the amount of soil bacteria, and the amount of soil bacteria increased by straw returning on the basis of balanced fertilization. However, high and low amount of straw The results of RDA analysis showed that the contents of ammonium nitrogen in paddy soils were the key factors regulating the bacterial community existing and transcribed in all the treated soils.In general, no matter at the level of DNA or c DNA, Fertilizer on the abundance of soil bacteria are viable and credible; but only to carry out research in the c DNA level, in order to find effective bacterial community adaptability to the environment.