Plant Protection Institute, Hebei Academy of Agricultural and Forestry Sciences, Baoding, P. R. China.
IPM Center of Hebei Province, Baoding, P. R. China.
PLoS One. 2018 Dec 3;13(12):e0205200. doi: 10.1371/journal.pone.0205200. eCollection 2018.
Wheat aphids damage wheat plants directly by feeding on them and indirectly by transmitting plant pathogenic viruses, both of which result in low yield and plant death. Due to their high root absorption and systemic characteristics, neonicotinoid insecticidal seed treatments are increasingly applied to control wheat aphids throughout the growing season in China. Ecological concerns are raised in some research, because neonicotinoids can persist and accumulate in soils. They are prone to leach into waterways, and are found in crop nectars and pollens, where they may be harmful to pollinators. Less information is available about the effect of neonicotinoid seed treatments on soil microorganisms. Here, we posed the hypothesis that neonicotinoids are not harmful to soil microbial communities. We tested our hypothesis by evaluating the effects of two neonicotinoids, imidacloprid and clothianidin, on soil microbiomes using high-throughput sequencing during three points in the wheat growth season. Except for the imidacloprid-treated soil in the seedling stage, the community richness and diversity were not affected according to Chao1, ACE and the Shannon indices, and species distribution histogram at the phylum level. However, Beta diversity indices showed that the species richness of the bacterial and fungal community was suppressed by neonicotinoids in seedling stage (high neonicotinoids concentrations), whereas by the reviving period, the changes reverted into stimulation of the soil microorganisms (low neonicotinoids concentrations). Overall, the general microbiome recovered at the end of the wheat planting season. Generally, wheat seed dressing with neonicotinoid insecticides control aphids during the entire growth period, and have no lasting adverse effects on the soil microbiome. This study provides an understanding of the influence of neonicotinoids on crop land ecology at the level of soil microbe communities.
麦蚜直接以小麦为食，间接传播植物病原病毒，导致小麦减产和植株死亡。由于具有较高的根部吸收和系统传递特性，新烟碱类杀虫剂种子处理剂在中国正被越来越多地应用于整个生长季来防治麦蚜。一些研究引起了人们对生态问题的关注，因为新烟碱类杀虫剂会在土壤中持久存在并积累。它们容易渗滤到水道中，并在作物花蜜和花粉中被发现，这可能对传粉媒介有害。关于新烟碱类杀虫剂种子处理对土壤微生物的影响，人们的了解较少。在这里，我们提出假设，即新烟碱类杀虫剂对土壤微生物群落没有危害。我们通过在小麦生长季的三个时间点使用高通量测序评估两种新烟碱类杀虫剂（吡虫啉和噻虫嗪）对土壤微生物组的影响来检验我们的假设。除了苗期用吡虫啉处理的土壤外，根据 Chao1、ACE 和 Shannon 指数以及门水平的物种分布直方图，群落丰富度和多样性没有受到影响。然而，Beta 多样性指数表明，在苗期（高新烟碱类浓度）新烟碱类抑制了细菌和真菌群落的物种丰富度，而在恢复期，这种变化又转化为对土壤微生物的刺激（低新烟碱类浓度）。总的来说，在小麦种植季结束时，一般微生物组得到了恢复。通常，用新烟碱类杀虫剂对小麦种子进行处理可以在整个生长期间控制蚜虫，并且对土壤微生物组没有持久的不利影响。这项研究提供了对新烟碱类杀虫剂对作物土地生态系统在土壤微生物群落层面影响的理解。
