Abstracts of content

Plant-soil microbiome as a predictive system to biocontrol efficiency (Alberto Acedo)

Understanding the effectiveness and potential mechanism of action of agricultural biological products under different soil profiles and crops will allow more precise product recommendations based on local conditions and will ultimately result in increased crop yield. We aimed to use bulk and rhizosphere soil microbial composition and structure to evaluate the effect of a Bacillus amyloliquefaciens strain inoculant on potatoes, and to explore its relationship with crop yield.

We implemented a field trial protocol and NGS and bioinformatics approaches to assess the bacterial and fungal biodiversity in 185 soil samples, distributed over four different time points -from planting to harvest -from three different geographical regions in the United States. In addition to variety, phenological stage of the potato plant and geography being important factors defining the microbiome composition and structure, the microbial inoculant applied as a treatment also had a significant effect. However, treatment preserved the native communities without causing a detectable long-lasting effect on the alpha- and beta-diversity patterns after harvest.

Specific taxonomic groups, and most interestingly the structure of the fungal and bacterial communities (measured using co-occurrence and co-exclusion networks), changed after inoculation. Additionally, we trained a Random Forest model that used soil microbiome composition and structure data to estimate if a bulk or rhizosphere soil sample came from a low or high yield block with relatively high accuracy, concluding that the structure of fungal communities is biomarkers of potato yield.

A biocontrol model for the bionematicide effect of bacillus FMCH001 (Lars Moelbak)

Plant pathogenic nematodes are one of the largest causes of crop damage and yield loss, and the failure to control their impact is one of the main yield eradicating factors for growers. Approximately 20% of crop production worldwide is lost annually due to nematode damage, with yield losses of up to 90% in severe cases; estimates put the cost to growers at USD 360 billion per year.

To combat nematodes, growers have traditionally used chemical nematicides. However, along with growing environmental concerns and tighter regulations, these solutions are becoming increasingly ineffective. Bionematicides on the other hand contain bacterial solutions that are strong root colonizers that create a physical and biochemical barrier. Microbes in these solutions colonize the plant roots, shield the roots and interact directly with nematodes, thus protecting the plant throughout its lifecycle.

In this presentation, Lars Moelbak, Director of Innovation, Plant Health at Chr. Hansen, outlines how a Chr. Hansen bionematicide featuring one particular bacillus strain (FMCH001) functions differently from traditional chemical nematicides, exhibiting a multimodal mode of action based on a high degree of root colonization to aid plant protection. Lars will also explain how Chr. Hansen is using this knowledge to continue to improve the testing and evaluation of the robustness of bionematicides of the future.