Seed mucilage in temperate grassland species is unrelated to moisture requirements.

Abstract

Myxospermy, the release of seed mucilage upon hydration, plays multiple roles in seed biology. Here, we explore whether seed mucilage occurs in a suite of temperate grassland species to test if the prevalence of species producing seed mucilage is associated with habitat type or seed characteristics. Seventy plant species found in wet or dry North American temperate grasslands were tested for the presence of seed mucilage through microscopic examination of seeds imbibed with histochemical stain for mucilage. Mucilage production was compared among species with different moisture requirements and seed mass. In this study, 43 of 70 of species tested produced seed mucilage. Seed mucilage did not differ based on habitat type, species moisture requirements, or seed mass. Most seed mucilage was non-adherent and did not remain stuck to the seed after extrusion. Seed mucilage was a common trait in the surveyed temperate grassland species and was observed in 61% of evaluated species. Surprisingly, seed mucilage was more common in temperate grasslands than in previous ecological surveys from arid/semiarid systems, which found 10%-31% myxospermous species. Given the high prevalence, seed mucilage may influence seedling ecology in temperate grasslands and requires further investigation.