不同改良方式对豆禾混播草地AMF的影响

The Effect of Different Grassland Improvement Methods on Soil AMF in Grass-Legume Mixtures

【目的】探究不同改良方式对豆禾混播草地的丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)群落及区系特征的影响机制。【方法】以云南省种羊场豆禾混播草地为研究对象,调查2019年直接改良(DR)草地与轮作改良(CR)草地,以围封(NG)草地为对照,借助高通量测序、菌丝测定与孢子密度测定技术,测定AMF群落特征。【结果】直接改良草地中孢子密度、球囊霉属(Glomus)显著高于轮作改良方式。孢子密度与土壤硝态氮、土壤微生物氮含量呈显著正相关关系,菌丝长度、菌丝密度与土壤氨态氮含量呈极显著正相关关系,与土壤速效磷含量呈极显著负相关关系。【结论】直接改良方式比轮作改良方式更有利于土壤养分的增加,更有利于AMF与植物共生关系的构建。

【Objective】The study aimed to investigate the influence of different grassland improvement practices on plant communities and the distinguishing characteristics of arbuscular mycorrhizal fungi(AMF)in legume-grass mixtures.【Method】High-throughput sequencing and mycelium and spore density measurement techniques were employed to determine the community characteristics of AMF in the directly improved grassland(DR)and the rotationally improved grassland(CR)in 2019.A fenced native grassland(NG)served as the control.【Result】Spore density and the abundance of the genus Glomus were significantly higher in the directly improved grassland(DR)than in the rotationally improved grassland(CR).There was a significant positive correlation between spore density and both soil nitrate nitrogen and soil microbial nitrogen.Additionally,a significant positive correlation was observed between soil ammonia nitrogen and both mycelium length and mycelium density.Conversely,there was a significant negative correlation between plant-available phosphorus and both mycelium length and mycelium density.【Conclusion】Direct improvement practices are more conducive to increasing soil nutrients and establishing symbiotic relationships than rotational improvement practices.