Thomsen Corrina, Loverock Laura, Kokkoris Vasilis, Holland Taylor, Bowen Patricia A, Hart Miranda
Department of Biology, University of British Columbia Okanagan, Kelowna, BC, Canada.
Department of Biology, University of Ottawa, Ottawa, ON, Canada.
PeerJ. 2021 Apr 22;9:e11119. doi: 10.7717/peerj.11119. eCollection 2021.
Arbuscular mycorrhizal (AM) fungi associate with most plants and can increase nutrient uptake. As a result, commercial inoculants called "biofertilizers" containing AM fungi have been developed and marketed to increase plant performance. However, successful establishment of these inoculants remains a challenge, and may be negatively impacted by competition with fungi already present (priority effects). Perennial agriculture may be more amenable if inoculants can be successfully established on crops prior to field planting.
Here, we inoculate grapevine () with a commercial inoculant in three treatments designed to manipulate the strength and direction of priority effects and quantified the abundance of the fungal strain before and after introduction using droplet digital PCR (ddPCR).
We found that the introduced strain did not establish in any treatment, even with priority advantage, and inoculated vines did not differ in performance from non-inoculated vines. Fungal abundance was not greater than in pre-inoculation soil samples during any of the five years sampled and may have been impaired by high available phosphorus levels in the soil. This study highlights the need to understand and evaluate how the management of the agricultural system will affect establishment before introduction of "biofertilizers", which is often unpredictable.
丛枝菌根（AM）真菌与大多数植物共生，能够增加养分吸收。因此，已开发并销售了含有AM真菌的商业接种剂，即“生物肥料”，以提高植物性能。然而，这些接种剂的成功定殖仍然是一个挑战，并且可能受到与已存在真菌的竞争（优先效应）的负面影响。如果接种剂能够在田间种植前成功定殖于作物上，多年生农业可能更适用。
在这里，我们用一种商业接种剂对葡萄（）进行接种，设置了三种处理，旨在控制优先效应的强度和方向，并使用液滴数字PCR（ddPCR）对引入前后真菌菌株的丰度进行量化。
我们发现，即使具有优先优势，引入的菌株在任何处理中都没有定殖，接种的葡萄藤与未接种的葡萄藤在性能上没有差异。在采样的五年中的任何一年，真菌丰度都不高于接种前的土壤样本，并且可能受到土壤中高有效磷水平的影响。这项研究强调，在引入“生物肥料”之前，需要了解和评估农业系统的管理将如何影响其定殖，而这往往是不可预测的。
