Zhang Huiting, Wang Wanyan, Honnas Loren, Mazzola Mark, Somera Tracey
Department of Horticulture, Washington State University, Pullman, Washington, USA.
Ecosystem Science and Management, Pennsylvania State University, State College, Pennsylvania, USA.
Appl Environ Microbiol. 2025 Jan 31;91(1):e0193724. doi: 10.1128/aem.01937-24. Epub 2024 Dec 10.
Arbuscular mycorrhizal fungi (AMF) are promoted as commercial bioinoculants for sustainable agriculture. Little is known, however, about the survival of AMF inoculants in soil and their impacts on native or pre-established AMF communities in root tissue. The current study was designed to assess the stability of pre-existing/nursery-derived AMF in apple rootstocks after being planted into soil containing a known community of AMF with a limited number of species. Root-associated endophytic communities (bacteria and fungi) are known to differ depending on apple rootstock genotype. Thus, an additional aim of this study was to explore the effect of apple rootstock genotype on AMF community structure. A greenhouse experiment was conducted in which a variety of apple rootstock genotypes (G.890, G.935, M.26, and M.7) were inoculated with a commercially available, multi-species AMF consortium. Nursery-derived AMF communities were sequenced, and changes to AMF community structure following cultivation in pasteurized soil (inoculated and non-inoculated) were assessed using a Glomeromycota-specific phylogenetic tree, which included 91 different AMF species from 24 genera. Results show that inoculant colonization potential was limited and that apple rootstocks serve as a significant source of inoculum from the nursery where they are produced. Rootstocks established relationships with introduced AMF in a genotype-specific manner. Regardless of colonization success, however, the inoculant caused alterations to the resident AMF communities of both Geneva and Malling rootstocks, particularly low abundance taxa. In addition, phylogeny-based analysis revealed a unique, well-supported clade of unknown taxonomy, highlighting the importance of using phylogenetic-based classification for accurate characterization of AMF communities.IMPORTANCEUnderstanding the impacts of introduced AMF on residential AMF communities is essential to improving plant productivity in nursery and orchard systems. In general, there is a dearth of data on the interactions of commercial AMF inoculants with pre-established AMF communities living in symbiosis with the host plant. The interplay between apple rootstock genotype and the endophytic root microbiome is also an area where more research is needed. This study demonstrates the potential for nursery-established AMF associations to be maintained when transplanted into the field. In addition to providing insight into rootstock/AMF associations, our study calls attention to the current issues attendant with relying on web-based databases for determining AMF identity. The use of phylogenetic tools represents one possible solution and may be of value to industry practitioners in terms of improving product composition and consistency.
丛枝菌根真菌（AMF）作为可持续农业的商业生物肥料受到推广。然而，关于AMF接种剂在土壤中的存活情况及其对根组织中本地或预先存在的AMF群落的影响，人们知之甚少。本研究旨在评估将苹果砧木中预先存在的/来自苗圃的AMF种植到含有已知有限物种AMF群落的土壤后其稳定性。已知根相关内生群落（细菌和真菌）因苹果砧木基因型而异。因此，本研究的另一个目的是探讨苹果砧木基因型对AMF群落结构的影响。进行了一项温室实验，用一种市售的多物种AMF联合体接种多种苹果砧木基因型（G.890、G.935、M.26和M.7）。对来自苗圃的AMF群落进行测序，并使用包含来自24个属的91种不同AMF物种的球囊菌门特异性系统发育树评估在灭菌土壤（接种和未接种）中培养后AMF群落结构的变化。结果表明，接种剂的定殖潜力有限，苹果砧木是其生产苗圃中接种体的重要来源。砧木以基因型特异性方式与引入的AMF建立关系。然而无论定殖是否成功，接种剂都会改变日内瓦和马林砧木的常驻AMF群落，尤其是低丰度类群。此外，基于系统发育的分析揭示了一个独特的、得到充分支持的未知分类单元分支，突出了使用基于系统发育的分类来准确表征AMF群落的重要性。重要性了解引入的AMF对常驻AMF群落的影响对于提高苗圃和果园系统中的植物生产力至关重要。一般来说，关于商业AMF接种剂与与宿主植物共生的预先存在的AMF群落之间相互作用的数据很少。苹果砧木基因型与内生根微生物组之间的相互作用也是一个需要更多研究的领域。本研究证明了苗圃建立的AMF关联在移植到田间时得以维持的潜力。除了深入了解砧木/AMF关联外，我们的研究还提请人们注意目前依赖基于网络的数据库来确定AMF身份所带来的问题。使用系统发育工具是一种可能的解决方案，在改善产品成分和一致性方面可能对行业从业者有价值。
