How Multispectral Imaging Supports Biopriming Research

Seed biopriming is a technique where seeds are coated with helpful, naturally occurring bacteria before planting, to give the plant a head start against stress and disease. One well-studied helper bacterium is Bacillus subtilis, and researchers have long known it can improve how seedlings grow. The tricky part has been figuring out exactly how much bacteria to use, and how to confirm it’s actually sticking to the seed, without cutting seeds open or relying on guesswork.

A study recently published in Scientific Reports, by researchers from the University of Pavia, Aarhus University, the University of Sfax, and the Agricultural University of Athens, tackled that problem using the VideometerLab instrument – a great example of how imaging technology can support plant science.

The Crops: Small Seeds, Big Climate Potential

The researchers worked with three legume crops that don’t get much attention but matter a lot to small farmers in difficult growing regions: grass pea, forage pea, and fenugreek. These crops are naturally tough and can handle poor soil and unpredictable weather, which makes them useful as climate change puts pressure on farming. The goal of the study was to make their seeds perform even better.

The team tested two treatments together: first soaking the seeds in water to “wake them up” (a step called hydropriming) and then coating them with Bacillus subtilis spores (biopriming). The water soak turned out to be the bigger driver of faster germination, but the bacterial coating still gave seedlings a helpful boost, encouraging stronger shoots and roots. That made the researchers want to understand the bacterial coating better and improve how it’s applied.

Where VideometerLab Comes In

Every seed has a unique surface texture, some smooth, some rough or bumpy, and this texture affects how well bacteria can stick to it. To study this, the researchers first captured images of the seed surfaces under a powerful microscope to map out these tiny bumps and grooves in detail.

Then came the spectral imaging step. The VideometerLab scans a sample using light at 20 different wavelengths, including wavelengths the human eye can’t see, and turns it into a detailed image showing how each point on the seed reflects light. Because the light reflects differently depending on what’s on the seed’s surface, this creates a fingerprint for the seed. The researchers used it to check whether they could spot the difference between plain seeds and seeds coated with bacteria, just by looking at how they reflected light, no cutting, staining, or lab chemistry required.

What They Found

It worked. Three specific wavelengths of light (645, 660, and 690 nm) were consistently good at telling coated and uncoated seeds apart. These wavelengths happen to be sensitive to chlorophyll, and that sensitivity seems to help reveal the bacterial layer sitting on top.

The team also confirmed something intuitive: rougher, bumpier seeds reflect less light, while smoother seeds reflect more. Since surface texture also affects how easily bacteria stick, this gives researchers a second, independent way to predict and double-check how a biopriming treatment is likely to perform on a given seed variety.

About the Technology

The VideometerLab is a multispectral imaging system that captures many wavelengths of light at once, well beyond what a standard camera or the human eye can pick up. It’s used by seed companies, breeders, gene banks, and research institutes around the world to assess seed quality, spot disease, sort varieties, and, as this study shows, explore how seed treatments actually work at the surface level. What made it useful here wasn’t just taking a picture of the seeds, but capturing consistent, repeatable data researchers could compare across treatments, varieties, and time points, something that’s hard to do reliably by eye.

Why This Matters

Right now, most biopriming recipes are worked out through trial and error: try a dose, see what happens, adjust, repeat. The approach in this study offers an enhancement. By first checking a seed’s surface texture and then using imaging to confirm how well a bacterial coating is holding on, researchers could design better treatments faster, with less guesswork. Over time, that kind of data could even help train AI models to recommend the right treatment for a given seed type automatically.

The researchers are upfront that this is early-stage work, tested so far on specific grass pea varieties under controlled lab conditions. Extending it to more crops, more bacterial strains, and real farm fields is the next step. But it’s a promising sign of how combining different imaging tools can shed light, quite literally, on questions that used to require a lot of trial and error to answer.

Source: Dueñas Jr, C., Pagano, A., Calvio, C. et al. Novel approaches for understanding and improving the effectiveness of seed biopriming. Scientific Reports 16, 10965 (2026). https://doi.org/10.1038/s41598-026-46096-7