丛枝菌根(AM)对根瘤菌趋化作用研究

The Chemotaxis of Arbuscular Mycorrhizal to Rhizobia

摘要:

对紫穗槐非接种(AM-+Rh-)、单接种根瘤菌(Rh+)、单接种AM真菌(AM+)和双接种(AM++Rh+)处理, 研究AM真菌、根瘤菌对宿主植物紫穗槐侵染情况, 并采用经过改良的根部微生物趋化试验手段研究AM真菌侵染根系后分泌物对根瘤菌的趋化性。实验结果表明：在接种AM++ Rh+情况下, 使宿主先于AM+、Rh+处理形成根瘤, 且双接种能够显著提高菌根侵染率; 在共生体形成期间, AM真菌与根瘤菌之间存在着识别互动反应和一定的信号物质, 接种AM真菌对根瘤菌有正趋化作用; 同时, 外界温度对AM真菌-宿主植物---根瘤菌三者共生体初始信号识别也起到一定的调控作用。

Abstract:

Through the study of symbiosis of AMF (Arbuscular mycorrhizal fungi)-Amorpha fruticosa, the infection sequence, the infection rates and the chemotaxis between AMF and rhizobia had been determined. The diversity of infection between AMF and rhizobia in time-space under the inoculation conditions of mon-innoculation (AM+) and dipl-innoculation (AM++Rh+) was investigated and the relationship between AMF and rhizobia in the chemotaxis test was studied. The results suggested that there were some signals beween AMF and rhizobia and there exsited auxoaction in coordination during the formation of symbiosis. The chemotaxis between the root-exudates and rhizobia under the inoculation conditions of AM-+Rh-, AM+ and AM++Rh+ in 25℃, 28℃, 31℃ showed that the surrounding conditions (temperature) in rhizosphere have some effects on the regulation of incipient identification signals in the tri-symbiosis of AMF-host- rhizobia.