Abstract: The experiment was conducted to observe the morphological structure of arbuscular mycorrhizas in both Citrus unshiu ‘Guoqing No.1’/Poncirus trifoliata and C. unshiu ‘Guoqing No.4’/P. trifoliata in field.Vesicles,arbuscules,entry points,internal hyphae,external hyphae and internal chlamydospores were observed in citrus roots,which indicated that citrus belonged to arbuscular mycorrhizal plants.There were few vesicles in arbuscular mycorrhizal roots,while arbuscules were observed everywhere.Entry points had diversiform modes.Arbuscular mycorrhizal structure was mainly found in elongation zone and maturation zone.In addition,we firstly observed that root cap and meristematic zone were infected by native arbuscular mycorrhizal fungi.

Key words: citrus, arbuscular mycorrhiza, entry point, infected place

摘要： 以田间栽培的‘国庆1号’温州蜜柑(Citrus unshiu ‘Guoqing No.1’)/枳(Poncirus trifoliata)和‘国庆4号’温州蜜柑(C.unshiu ‘Guoqing No.4’)/枳为试材观察丛枝菌根的形态结构。结果表明,泡囊、丛枝、侵入点、根内菌丝、根外菌丝、根外厚垣孢子等结构出现在柑橘根系中,说明柑橘属于典型的丛枝菌根植物。丛枝菌根结构中泡囊出现概率较小,丛枝随处可见,侵入点多样化。丛枝菌根的结构主要存在柑橘根段的伸长区和成熟区,首次观察到根冠和分生区也有侵染。

关键词: 柑橘, 丛枝菌根, 侵入点, 侵染部位