Physiological studies of the halophyte Salicornia bigelovii: A potential food and biofuel crop for integrated aquaculture-agriculture systems

Numerous studies over the past thirty years have demonstrated the technical feasibility of using seawater and other saline water supplies for irrigation. Through the use of saline water for irrigation, highly salt-tolerant crops derived from wild halophytes could greatly increase global water and land resources available for agriculture. Large supplies of brackish water and seawater from different sources are available in areas suitable for production of salt-tolerant crops to grow. Dwarf glasswort Salicornia bigelovii Torr. (Chenopodiaceae), is a leafless, succulent, small-seeded, annual saltmarsh plant, with demonstrated potential as a saline water crop for coastal deserts. Currently, S. bigelovii is commercially cultivated as a minor specialty vegetable for U.S. and European fresh produce markets. It is also a potential oilseed, forage, biomass crop, and a promising carbon sequestration plant. In the first chapter of this document we describe a study where we grew Salicornia bigelovii from seedlings, of plants originating along the Texas coast, in saline, drying soils in a greenhouse experiment. The effects of drought and salinity stress were additive. Optimal growth and water use efficiency coincided at 0.35-0.53 M NaCl. The plants were tolerant of high salinity but exhibited little drought tolerance. Salicornia bigelovii plants varied little in their uptake of Na + for osmotic adjustment, with final Na + contents of 18% on a dry mass basis. Both growth and water use efficiency of Salicornia bigelovii were affected by salinity. Also, Na +, the primary cation involved in osmotic adjustment of this species, apparently stimulates growth by mechanisms apart from its role as an osmoticum. In the second chapter of this dissertation we developed a research study where we evaluated the production and