铜尾矿白羊草各生长阶段根际土壤丛枝菌根真菌群落特征

Characteristics of arbuscular mycorrhizal fungi communities in rhizosphere soil at different growth stages of Bothriochloa ischaemum in copper tailings

以北方铜业铜矿峪矿十八河尾矿坝主要恢复植被白羊草为研究对象,分析重金属污染环境下,白羊草不同生长阶段根际土壤中丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)群落结构与多样性的变化特征,研究各生长阶段白羊草AMF群落结构与环境因子的相互关系。结果发现,白羊草不同生长阶段根际土壤的理化性质和酶活性均存在显著差异。白羊草各生长阶段根际土壤中具有相同的优势科球囊霉科,但AMF群落组成在各个生长阶段的结构存在明显不同。白羊草各生长阶段主要AMF物种对生态因子的响应表现为:幼苗期根际土壤中球囊霉科主要受土壤养分和碳氮比的影响,分蘖期根际土壤中多样孢囊霉科的主要影响因子为土壤pH,成熟期根际土壤中,双型囊霉科双型囊霉科与土壤过氧化氢酶显著相关,类球囊霉科与土壤脲酶显著正相关。总体看来,白羊草各生长阶段根际土壤AMF群落特征受到的生态因子影响具有明显差异。这有助于进一步认识污染环境下AMF的群落特征及其关键影响因子,为铜尾矿生态恢复过程中发掘和利用菌种资源提供科学依据,从而提高矿区生态修复效率。

This study was conducted on Shiba River tailings of the Northern Copper Mine, which was the largest underground copper mine in China. Bothriochloa ischaemum was the dominant species in this copper tailings dam. We studied the variations characteristics of arbuscular mycorrhizal fungi(AMF) structures and diversities in rhizosphere soil of B. ischaemum at different growth stages. Simultaneously, we analyzed the relationship between the AMF community structures and environmental factors. Our results showed that the physicochemical properties and enzyme activities of rhizosphere soil were significantly different in different growth stages of B. ischaemum. The rhizosphere soil had the same dominant AMF family, but the structure of AMF community was obviously different in plant development processes. Glomeraceae were mainly affected by soil nutrient and carbon nitrogen ratio at seedling stage, and the main influencing factor was soil pH for Diversisporaceae at tillering stage. Ambisporaceae were significantly correlated with soil catalase, and Paraglomeraceae were positively correlated with urease at mature stage. Taken together, the effects of ecological factors on the community characteristics of rhizosphere soil AMF in different growth stages of B. ischaemum were significantly different. These results deepen our understanding of the AMF community characteristics and their driven factors in polluted environmental area in future work. This study provides a scientific basis for exploring and available bacteria resources in processes of ecological restoration in copper tailings, so as to improve the ecological restoration efficiency of mining areas.