Japanese Oblate Film as a Novel Method for Seed Handling and Activation in Microgravity

Abstract In-situ food production for long-duration space missions is currently reliant on crop production, with plants grown from seed serving as a potential source of nutrient supplementation to astronaut diets. Microgravity presents significant challenges to seed handling, growth system integration, and storage. A primary concern is the generation of environmental debris and particulates. This will require extended-duration spaceflight missions to incorporate innovative and reliable methods to handle and prepare seeds for cultivation. This study investigates the potential of Japanese oblate film, a thin, starch-based, edible film traditionally used to wrap ill-tasting powdered medicines, as a method for seed handling in space environments. These films feature a thin, flexible structure that facilitates efficient handling and a water-soluble composition, allowing for integration into cultivation systems. Japanese cherry red radish seeds were adhered to oblate sheets, immobilizing them to prevent debris formation during handling and ensure consistent positioning for growth. The sheets were placed on non-enriched agar media plates, activating the seeds and simulating passive hydroponic systems that could be utilized during future space missions. Results indicate that seeds prepared with oblate film exhibited significantly faster germination rates within the first 24 hours and higher overall germination rates over a seven-day period compared to control groups. This study demonstrates the potential of Japanese oblate film as an effective solution for seed handling and activation in microgravity environments, with possible applications for storage in long duration space agriculture operations.