You will find here experiments and exploratory trials currently in progress, updated periodically. Interested readers can follow the development (in brief summary form) of certain experiments as monitoring continues and progress is made. The goal and a short context appear immediately below the title, and the latest updates always appear at the top.
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- 363 Long-Term Storage of R. irregularis
- 368 Trifolium repens + Funneliformis geosporus
- 372 Fragaria vesca + Funneliformis geosporus
- 373 Anthoceros agrestis
- Suggestions and Research Avenues for the Curious
363 Long-Term Storage of Rhizophagus irregularis
Purpose and Context: This experiment aims to test the survival of Rhizophagus irregularis spores in the polymer. In 2020, colonized polymer grains were collected and placed in a 50 ml tube, sealed and refrigerated for later use. In 2026, the tube is still in the refrigerator, untouched. On February 22, 2026, six dishes containing Plantago lanceolata seedlings were inoculated with these colonized grains. Each grain contains more than 25 spores interconnected in a network.
March 16, 2026: after just three weeks, new hyphae can already be detected in all six dishes. This is admittedly very early, but it already suggests that storage did not kill the fungus. It can be hypothesized that a network of interconnected spores is more resilient than isolated spores, with the polymer grain helping preserve the network’s integrity. Here is a photo taken in one of the dishes.
April 3, 2026: confirmation — hyphae and new spores are observed in the polymer of all six dishes. The spores spent six years in the refrigerator and can still start new cultures: a remarkable result.
368 Trifolium repens + Funneliformis geosporus
April 9, 2026: this is a trial of this plant as a host. Sown in a Biosta germination tray on February 18, transferred to a dish on February 23, 2026. As of April 9, the plants are moderately healthy: they do not seem to particularly enjoy the moist environment of the dishes, but show several well-developed leaves. At this point, they are sufficiently advanced to be inoculated with polymer grains colonized by Funneliformis geosporus. Further observations will show how this progresses.
372 Wild Strawberry Fragaria vesca + Funneliformis geosporus
April 3, 2026: this plant is being tested once again as a potential host for Funneliformis geosporus.
The seeds were germinated in a Biosta germination tray. They were slow to germinate — a good three weeks before they could be transferred to a dish — and the tiny seedlings are delicate to handle. Even so, they are developing quite well for now. Placed in the germination tray on February 18, 2026 and transferred to a dish on March 12, here is their appearance on April 3, 2026.
April 9, 2026: inoculation with Funneliformis geosporus. Two seedlings died, their short roots not having been well positioned, which caused them to dry out. The remaining seedlings stayed healthy, confirming that the setup allows for their culture. Two seedlings already show a stolon. Whether the medium is optimal remains unknown, but the plants are surviving, which is enough to move forward: they were therefore inoculated with polymer grains already colonized by Funneliformis geosporus. A brief literature search turned up no evidence of symbiosis between these two organisms — making this an interesting pairing to test.
Exp 373 Anthoceros agrestis
Purpose and Context: this trial aims to grow a bryophyte using the polymer and/or vermiculite, and eventually to attempt inoculating it with a mycorrhizal fungus. Initially, three small plant fragments were placed on the vermiculite and three others on the polymer; they will be irrigated with M2P. These fragments come from a sterile agar culture but are now being grown without sterility. Observations will show whether the bit of agar residue still stuck to the seedlings causes any issues.
March 15, 2026: here are a few images of the initial setup.
April 3, 2026: the seedlings are all doing very well, showing a healthy green color, though they do not seem to be growing quickly.
June 2026: growth of the seedlings has been practically nil to date. In addition, the plants are too small, making it impossible to position roots or rhizoids on the polymer side and the “foliage” on the vermiculite side. The plants on the polymer side require some light, and this light proved sufficient to allow a large amount of microscopic algae to develop. The dishes now show a striking fluorescent green color.
The conclusion is that this species is not well suited to the protocol originally planned. End of this experiment.
Suggestions and Research Avenues
- Test different types of polymer. Hortasorb polymer works well. Stockosorb 660 was also tested and worked, though not as well as Hortasorb. The two polymers likely differ chemically, which could explain, among countless possible reasons, this gap in performance. It would be worthwhile to validate or identify other high-performing polymers for this application.
- Test different mycorrhizal fungus–host plant pairings. Some fungi, such as Rhizophagus irregularis, appear to be accepted by a very wide range of host plants, whereas other fungi might instead show limited preferences for certain plants or plant families.