岩溶与非岩溶区稻田土壤CO_2固定细菌的丰度比较

Comparison of abundance of CO_2 fixing microbes in paddy soil from karst and non-karst area

以桂林毛村岩溶试验场稻田土壤为研究对象,以cbbLR1、cbbLG1和cbbM为CO_2固定细菌的指示基因,采用荧光定量PCR技术,对比三者在岩溶区、混合区与非岩溶区中的丰度。结果表明,cbbLG1基因在岩溶区的丰度显著高于混合区和非岩溶区,最大值为1.42×10~9拷贝·g^(-1);cbbLR1和cbbM基因在混合区的丰度显著高于岩溶区和非岩溶区,最大值为2.06×10~9拷贝·g^(-1)和3.35×10~7。相关性分析表明,cbbLG1的丰度与土壤中有机碳质量分数、全氮质量分数及阳离子交换量显著相关;三个cbbL基因对pH的敏感度不同:pH与cbbL G1基因呈显著正相,而与cbbM基因呈显著负相关。

oil samples were collected from paddy field in the Maocun karst experimental site to study the gene abundance of cbbLR1,cbbLG1 and cbbM,as the index of CO2 fixing bacteria in typical karst area,mixed area and non-karst area with the utilization of real-time quantitative PCR technology.The results showed that the gene abundances of cbbLG1 in karst area were generally higher than that in non-karst area,and the maximum value was 1.42×109 copies·g^（-1）.The gene abundances of cbbLR1 and cbbMin mixed area were significantly higher than that in non-karst area,and the maximum values were 2.06×109 copies·g^（-1） and 3.35×107 copies·g^（-1）.Correlation analysis showed that the abundance of cbbLG1 was significantly correlated with organic carbon mass fraction,total nitrogen mass fraction,and cation exchange capacity in the soil,which were significant factors that affect the gene abundance of cbbLG1.The abundance of the three cbbLgenes had different sensitivity to pH,which was significantly positive correlated with the cbbLG1 gene and negatively correlated with the cbbM gene.