作　　者： (王娟英）; (许佳慧）; (吴林坤）; (吴红淼）; (朱铨）; (孔露霏）; (林文雄）;

机构地区： 福建农林大学生命科学学院,福州350002 福建农林大学生物农药与化学生物学教育部重点实验室,福州350002 福建农林大学农业生态过程与安全监控重点实验室,福州350002

出　　处： 《生态学报》 2017年第17期5621-5629,共9页

摘　　要： 以不同连作年限怀牛膝根际土壤为材料,采用土壤农化分析技术和磷脂脂肪酸生物标记法,对土壤理化性质以及根际微生物群落结构进行分析。结果表明:怀牛膝连作会使大部分大量元素(全磷、碱解氮、速效磷和速效钾)含量上升,而全氮、全钾的变化并无明显趋势。全量钙、全量镁、全量锰和有效锌的含量也会随着连作年限的增加而增加。研究发现,怀牛膝连作1a的土壤与对照相比,根际土壤微生物群落结构差别不大,但是与连作10a和30a的土壤相比微生物多样性却发生了明显变化。土壤中总PLFAs、细菌、革兰氏阴性菌Gram(-)及真菌含量都随连作年限增加而明显上升,微生物多样性增加,且革兰氏阳性菌Gram(+)/革兰氏阴性菌Gram(-)的比值随着连作年限的增加而下降。此外,土壤中一些嗜热解氢杆菌和真菌等参与土壤物质循环和木质素降解的微生物类群数量明显增加,假单胞菌等有益微生物类群也显著增多,这是牛膝连作促进作用的生物学基础。研究用药用植物怀牛膝证明了植物根际微生物结构和功能多样性对植物连作促进或连作抑制作用的产生与控制的生态学意义。 In this study, the rhizosphere soils of Achyranthes bidentata, which was grown in a monoculture for multiple years, were investigated for analyzing the major elements, trace elements and rhizosphere microbial community structure by means of agricultural chemistry and phospholipid fatty acid （PLFA） analysis techniques. The results showed that consecutive monocultures of A. bidentata increased the contents of major elements （total phosphorus, alkaline hydrolysis nitrogen, available phosphorus, and available potassium）. However, the ability of consecutive monocultures to change the total nitrogen content and total potassium was not obvious. In addition, total calcium, total magnesium, total manganese, and available zinc contents also increased with the increasing years of monoculture. Further analysis of PLFA profiles showed that there were no obvious differences in the rhizosphere microbial community structures between the control and newly planted A. bidentata. Besides, different results were depicted by 10 years and 30 years of consecutive monoculture, which showed that the total PLFA, bacteria （especially G-）, and fungal content increased significantly, and the G＋/G- ratio decreased with increasing years of monoculture. Moreover, some microbes involved in material cycling and lignin degradation, such as Hydrogenobacter, fungi （PLFA18：2ω6,9）, and some beneficial bacteria including Pseudomonas increased significantly with increasing years of monoculture. These results suggest the important biological basis for the promotion mechanism of A. bidentata under a monoculture system. The case study exemplifies the ecological significance of rhizosphere microbial structure and its functional diversity in monoculture promotion or monoculture inhibition.

关 键 词： 怀牛膝 连作促进 磷脂脂肪酸 根际微生物