Increased plant phosphorus uptake and growth as a result of inoculation with arbuscular mycorrhizal (AM) fungi is observed less often under field conditions than in pot experiments. Interaction between introduced and indigenous AM fungi is one of the reasons for ineffectiveness of inoculation in the field. We aimed to distinguish the effect of introduced and indigenous AM fungi on phosphorus uptake and growth of Allium fistulosum in a field experiment. Superphosphate was applied in the ratio of 0 or 317 P kg ha⁻¹ to the plots fumigated with or without dazomet that is a common soil fumigant. Seedlings of A. fistulosum that had been inoculated with or without Rhizophagus spp. strain R-10 were transplanted into the plots. AM fungal colonization, OTU read abundance of indigenous and introduced AM fungi, shoot P concentration, and shoot growth were measured at 31, 60, 90, and 131 days after transplanting (DAT). We could partially separate the effects of introduced AM fungi from indigenous AM fungi by fumigation with dazomet. Though neither inoculation nor P level affected shoot fresh weight and shoot P content in the non-fumigated main plot at 131 DAT, significantly higher shoot fresh weight was obtained by the inoculation with no P fertilizer in the fumigated main plot at this final sampling stage. These results indicate that the colonization of roots by introduced AM fungi is affected by the abundance of indigenous AM fungi and this interaction determines growth response of host plants under field conditions.

由于接种丛枝菌根 (AM) 真菌导致植物磷吸收和生长增加，在田间条件下观察到的情况比在盆栽试验中少。引进的和本地的 AM 真菌之间的相互作用是田间接种无效的原因之一。我们的目的是在田间试验中区分引入和本地 AM 真菌对Allium fistulosum磷吸收和生长的影响。过磷酸钙以 0 或 317 P kg ha ^-1的比例施用到用或不用达唑美（一种常见的土壤熏蒸剂）熏蒸的地块。接种或不接种根瘤菌的A. fistulosum幼苗属 将菌株 R-10 移植到地块中。在移植后 (DAT) 31、60、90 和 131 天测量 AM 真菌定植、OTU 读取本地和引入 AM 真菌的丰度、枝条 P 浓度和枝条生长。我们可以通过使用 dazomet 熏蒸来部分分离引入的 AM 真菌和本地 AM 真菌的影响。尽管接种和磷水平均不影响 131 DAT 非熏蒸主小区的地上部鲜重和地上部 P 含量，但在最后采样阶段，在熏蒸主小区中接种无磷肥的地上部鲜重明显更高。这些结果表明，引入的 AM 真菌对根的定殖受本地 AM 真菌丰度的影响，这种相互作用决定了寄主植物在田间条件下的生长反应。