Nutrient availability and plant phenological stage influence the substrate microbiome in container-grown Impatiens walleriana ‘Xtreme Red’

Authors: QUIJIA PILLAJO, JUAN - THE OHIO STATE UNIVERSITY; CHAPIN, LAURA - THE OHIO STATE UNIVERSITY; QUIROZ-MORENO, CHRISTIAN - THE OHIO STATE UNIVERSITY; Altland, James; JONES, MICHELLE - THE OHIO STATE UNIVERSITY

Submitted to: BMC Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2024
Publication Date: 3/6/2024
Citation: Quijia Pillajo, J., Chapin, L.J., Quiroz-Moreno, C.D., Altland, J.E., Jones, M. 2024. Nutrient availability and plant phenological stage influence the substrate microbiome in container-grown Impatiens walleriana ‘Xtreme Red’. BMC Plant Biology. 24. Article 176. https://doi.org/10.1186/s12870-024-04854-7.
DOI: https://doi.org/10.1186/s12870-024-04854-7

Interpretive Summary: The floriculture industry relies on soilless substrates and chemical fertilizers to grow high-quality and marketable-sized plants. Recent research has shown that the plant associated microbial communities play an important role in modulating plant nutrient uptake, greenhouse gas emissions, and nutrient leaching. While the soil microbiome has been extensively studied, less information is available about the microbiome of soilless substrates. Developing microbial-based solutions to improve nutrient acquisition and plant visual quality requires a deep understanding of substrate and host-associated microbiomes and their responses to management practices such as fertilization. This study explored the composition and diversity of bacterial communities associated with a peat-based substrate used for container culture of Impatiens walleriana at different phenological stages and under low, optimum, and high fertilization. Community composition was influenced by phenological stage and fertilizer level, and phenological stage had a stronger influence on microbiome composition than fertilizer levels. Substrate microbiome composition exhibited a significant association with total organic carbon, chloride, sulfate, fluoride, phosphate, and magnesium. Phenological stage and fertilizer treatments did not affect microbial diversity. Our results provide insight into the influence of the plant and agricultural inputs in the substrate microbiome of container-grown ornamentals.

Technical Abstract: The microbiome plays a fundamental role in plant health and performance. Soil serves as a reservoir of microbial diversity where plants attract microorganisms via root exudates. The soil has a huge impact on the composition of the rhizosphere microbiome, but greenhouse ornamentals are commonly grown in soilless substrates. While soil microbiomes have been extensively studied in traditional agriculture to improve plant performance, health, and sustainability, information about the microbiomes of soilless substrates is still limited. Thus, we conducted an experiment to explore the microbiome of a peat-based substrate used in container production of Impatiens walleriana, a popular greenhouse ornamental plant. We investigated the effects of plant phenological stage and fertilization level on the substrate microbiome. The top five bacterial phyla present in the substrate were Proteobacteria, Actinobacteria, Bacteriodota, Verrucomicrobiota, and Planctomycetota. The substrate core microbiome was represented by 48 ASVs. Community composition was influenced by phenological stage and fertilizer level, and phenological stage had a stronger influence on microbiome composition than fertilizer levels. Substrate microbiome composition exhibited a significant association with total organic carbon, chloride, sulfate, fluoride, phosphate, and magnesium. Phenological stage and fertilizer treatments did not affect alpha-diversity. Our results provide insight into the influence of the plant and agricultural inputs in the substrate microbiome of container-grown ornamentals.