Moisture content, temperature, and relative humidity influence seed storage and subsequent survival and germination of Vallisneria americana seeds

• Seed storage of Vallisneria americana, a submerged aquatic plant, was studied.
• Seed survival increased when seeds were stored at 3 °C and 95% humidity.
• Germination was quicker when seeds were stored at ambient temperature and higher humidity levels.
• As time in storage increased, seeds required moisture content between 20 and 30% for successful germination.
• Seeds did tolerate desiccation to 4% moisture content and still germinated.

Loss of aquatic plant species has occurred in coastal and freshwater habitats throughout the world. In particular, population and habit loss of the submerged aquatic species, Vallisneria americana Michx., have made it a potential restoration candidate. For successful restoration, reliable seed sources are vital for producing plants or for direct seeding. Seed survival and their ability to retain viability through storage are key components for successful reproduction. Seed storage and subsequent germination of V. americana were studied over a 6-month period to determine the conditions that retain seed vigor. Seeds were stored at three humidity levels 11%, 50%, 95% using saturated salts and ambient humidity for 1, 2, 4, and 6 months at either cold or ambient temperatures. After storage intervals, seed moisture content, embryo viability, and germination were determined. Timing of germination and seed survival were analyzed using semi-and non-parametric analyses. Storing seeds at lower RH levels for longer periods reduced seed survival and resulted in later germination. Germination and seed survival increased in seeds stored at higher relative humidity and led to earlier germination. Seeds of V. americana from the northern Gulf of Mexico were shown to be desiccation tolerant and have orthodox seed characteristics.