ABSTRACT

Agricultural practices may lead to a decline in the presence and abundance of natural arbuscular mycorrhizal fungi (AMF). AMF inoculation can be an environmental friendly alternative or complement to chemical fertilizers in agriculture. Initially, through ribosomal DNA internal transcribed spacer (ITS) metabarcoding, we characterized the composition of fungal communities from three organic orchard soils, as well as from three adjacent non-cultivated soils. Organic orchard management had a negative impact on AMF community, leading to reduced alpha diversity and relative abundance of AMF taxa, compared to non-cultivated soil (e.g. 10 vs. 11 in richness and 2.1 vs. 2.6 in Shannon index). Using trap plants, we multiplied the AMF communities from the abovementioned orchard and non-cultivated soils. Afterward, a microcosm experiment was carried out to study the effect of inoculation with these AMF communities on (i) lettuce (Lactuca sativa L.) yield and nutritional quality (two consecutive crops), and (ii) root fungal communities. During the second crop cycle, AMF inoculants led to higher lettuce yields (by an average of 186%, irrespective of the origin of the inoculum), but resulted in no substantial modification of lettuce nutritional quality. Moreover, AMF inoculants did not exert a significant effect on fungal (including AMF) or AMF communities.

摘要

农业实践可能导致天然丛枝菌根真菌 (AMF) 的存在和丰度下降。AMF 接种可以是一种环境友好的替代品或农业化学肥料的补充。最初，通过核糖体 DNA 内部转录间隔子 (ITS) 元条形码，我们表征了来自三个有机果园土壤以及三个相邻的非耕地土壤的真菌群落组成。与非耕地土壤相比，有机果园管理对 AMF 群落产生负面影响，导致 AMF 类群的 alpha 多样性和相对丰度降低（例如，丰富度为 10 对 11，香农指数为 2.1 对 2.6）。使用诱捕植物，我们从上述果园和非耕地土壤中繁殖了 AMF 群落。之后，Lactuca sativa L.) 产量和营养质量（连续两季作物），以及 (ii) 根部真菌群落。在第二个作物周期中，AMF 接种剂提高了生菜产量（平均提高 186%，与接种物的来源无关），但并未显着改变生菜的营养质量。此外，AMF 接种剂对真菌（包括 AMF）或 AMF 群落没有显着影响。