论文部分内容阅读
【目的】研究腐植酸(HA)对土壤氨氧化古菌(AOA)的影响,进而探讨HA对土壤氮循环的作用。【方法】采用末端标记限制性多态性分析(T-RFLP)和实时定量PCR技术,研究了两种腐植酸(原生腐植酸-cHA和降解后的腐植酸-bHA)与尿素一同施加于土壤中的氨氧化古菌(AOA)和古菌的群落结构及数量的变化。【结果】只加尿素的处理AOA数量明显增加,其群落结构也发生明显变化,而加入尿素和两种腐植酸(HA)的处理土壤中,AOA数量增加得到明显的抑制,且典范对应分析(canonical correspondence analysis,CCA)表明尿素是影响AOA群落结构的最大因素,而HA可以缓冲尿素对AOA群落结构的影响,从而可以稳定AOA的群落结构。只加入尿素的处理还导致了古菌数量降低,而两种HA均抑制古菌数量的降低,表明HA可以缓冲尿素对古菌的影响。CCA分析表明时间是影响古菌群落结构的最重要因素,将时间作为共变量的部分典范对应分析(partial canonical correspondence analysis,pCCA)表明除时间外古菌的群落结构对cHA也比较敏感。【结论】这些结果表明HA通过抑制AOA数量而调控其与植物竞争氨来减少氨的损失,从而提高尿素利用率。
【Objective】 The purpose of this study was to investigate the effect of humic acid (HA) on soil ammonia oxidizing archaea (AOA) and to explore the effect of HA on soil nitrogen cycling. 【Method】 Two kinds of humic acid (primary humic acid-cHA and degraded humic acid-bHA) were applied to soil together with urea by T-RFLP and real-time quantitative PCR In the AOA and archaeal community structure and quantity changes. 【Result】 The results showed that the amount of AOA increased with the addition of urea, and the community structure also changed obviously. However, the increase of AOA was significantly inhibited by the addition of urea and two humic acids (HA) canonical correspondence analysis (CCA) showed that urea was the most important factor influencing AOA community structure, and HA could buffer the influence of urea on AOA community structure and thus could stabilize the community structure of AOA. Treatment with only urea also led to a decrease in the number of archaea, while both HA inhibited a decrease in the number of archaea, indicating that HA can cushion the effect of urea on archaea. CCA analysis showed that time was the most important factor affecting the archaeal community structure. Partial canonical correspondence analysis (pCCA) indicated that archaeal communities were more sensitive to cHA than time. [Conclusion] These results indicate that HA regulates its ability to compete with plant ammonia for reducing the loss of ammonia by inhibiting the amount of AOA, thereby increasing urea utilization.