A Sticky Situation: The Interaction Between Mucilage and Substrate on Seedling Success Varies Across Species

Seed mucilage (a slimy, gel-like substance that retains water around the seed) is known to play a significant role in germination and seedling success (root length). During this research, we tested the effect of seed mucilage across different environmental contexts on germination and also on the root length of seedlings. We hypothesized that: mucilage promotes germination, the effect of mucilage depends on context (sand, soil, and bare), and mucilage influences root length. For this experiment, we counted seeds for 6 species and placed them in their specific treatment. We then removed the mucilage from some seeds and placed all seeds into their respective substrate, and let them sit overnight. The next day, we sifted through the substrates and placed the seeds into petri dishes. Once we saw germination, we measured the root length, in millimeters, with calipers. Our results showed that only 3 species germinated (Garden Cress, Holy Basil, and Chia). In certain species mucilage decreases germination when covered; despite increasing when bare and having no effect on some species. With respect to root length, mucilage increases root growth in certain species, although sometimes only temporarily, or it may not have a significant impact at all. We concluded that seed mucilage's impact on germination and root length varies between species. We believe this could be due to the different chemical composition each seed has, in addition to the specific amount of mucilage each seed produces.