Protocols for Use of Potamogeton perfoliatus and Ruppia maritima Seeds in Large-Scale Restoration

Abstract

Restoration of submerged aquatic vegetation from seed has been hampered by a lack of information on the appropriate conditions for collecting, processing, and storing seeds prior to dispersal. Seeds must be processed and stored under conditions that maintain seed viability, meet dormancy requirements, and prevent premature germination. This study examined the effects of collection date, processing technique, aeration, storage and induction temperature and salinity, and storage period on seed germination of two mesohaline aquatic species, Potamogeton perfoliatus and Ruppia maritima. Collection date and processing technique were significant factors affecting seed yield from donor populations. Seeds of both species remained viable and germinated best when stored at 4 • C, and then exposed to freshwater induction conditions. However, their responses to other factors differed. Aeration during storage was necessary in order to maintain viability of P. perfoliatus seeds, whereas it was unnecessary for R. maritima seeds. Storage in freshwater at 4 • C prevented germination of P. perfoliatus seeds, while high salinity during cold storage was necessary to minimize premature germination of R. maritima. Mean germination time of P. perfoliatus was dependent on storage salinity; in contrast, mean germination time of R. maritima seeds was dependent on induction salinity. These differences indicate that the methods required to produce large quantities of underwater plant seed amenable to large-scale restoration efforts must be tailored to the specific requirements of individual species and must consider the range of processes from initial harvest through seed testing prior to field establishment.

Tolerance of Ruppia sinensis Seeds to Desiccation, Low Temperature, and High Salinity With Special Reference to Long-Term Seed Storage

“…Studies of Zostera seagrass seed storage suggested that wet conditions at high salinity and cold temperatures can inhibit seed germination ( Kaldy et al, 2015 ; Infantes et al, 2016 ; Xu et al, 2016 ). A study of R. maritima seed storage showed that both salinity and temperature could be manipulated as storage conditions to retain the vigor of seeds ( Ailstock et al, 2010 ); however, due to germination of seeds during the storage at 4°C and ≤30 psu in their work, the storage condition is not optimal for long-term Ruppia seed storage.…”

Effects of Planting Depth, Sediment Grain Size, and Nutrients on Ruppia maritima and Potamogeton perfoliatus Seedling Emergence and Growth

“…Ruppia maritima seeds were stored at 4°C in deionized water adjusted to a salinity of 30 using Hawaiian Marine Salts (Hawaiian Marine Imports, Inc., Houston, TX, U.S.A.), until the experiments were performed; P. perfoliatus seeds were stored at 4°C with aeration in deionized water. These conditions have been shown to optimize germination of seeds these species harvested from mesohaline regions of the Chesapeake Bay (Ailstock et al 2010).…”

“…In this case, deionized water was used as a control (zero nutrients) for the two levels of nutrient treatments to indicate the amount of growth that could be expected from a developing seed embryo relying on stored seed reserves alone. These three solutions have been shown to stimulate seed germination or support vegetative growth of axenic plant cultures of these species (Ailstock et al 1991, 2010). Plates were incubated for 28 days at the previously identified temperature and illumination level.…”

“…Ruppia maritima seeds were collected from a population growing in the St. Mary's River in Calvert County, Maryland, and P. perfoliatus seeds were harvested from perennial beds at the headwaters of Marshy Creek in Queen Anne's County, Maryland. Seeds were collected in July and August 2006 and processed according to the methods described in Ailstock et al (2010). Ruppia maritima seeds were stored at 4 • C in deionized water adjusted to a salinity of 30 using Hawaiian Marine Salts (Hawaiian Marine Imports, Inc., Houston, TX, U.S.A.), until the experiments were performed; P. perfoliatus seeds were stored at 4 • C with aeration in deionized water.…”

An Introduction to a Special Issue on Large-Scale Submerged Aquatic Vegetation Restoration Research in the Chesapeake Bay: 2003-2008

“…Considerably less effort was expended in planting seeds of SAV species other than Z. marina , largely because of a lack of information on suitable protocols for the collection, processing, storage, and subsequent distribution of large numbers of seeds. Methods for collecting, processing, and storing large quantities of Ruppia maritima and Potamogeton perfoliatus seeds began to be developed in 2004 (Ailstock & Shafer 2004, 2006), and protocols for using seeds of these species in restoration plantings are described in Ailstock et al (2010 a ). In 2004 and 2005, more than a million seeds of these two species were distributed at two sites in the mid‐Chesapeake Bay (Table 1).…”