Plants that are worth their salt

With about 10 percent of the land on Earth affected by salt, plants that thrive in saline marshes may hold a key to increasing global food supplies.

At UD, marine botanists Jack Gallagher and Denise Seliskar, co-directors of the Halophyte Biotechnology Center, are conducting research on these plants in the College of Marine and Earth Studies. Halophytes, or plants that grow in salty conditions, also are important in efforts to restore wetlands around the world.

While salt is toxic to most plants and inhibits them from extracting water from the soil, plants such as Spartina (cordgrass), Distichlis (saltgrass) and Salicornia (pickleweed) have evolved mechanisms that allow them to survive in saline coastal marshlands, Gallagher says.

In the First State alone, about 90,000 acres of salt marshes line the Delaware River and Bay estuaries, while nationally there are some 12 million acres of salt marshes. Besides being able to survive in salty soil, halophytic plants can be cultivated to grow in areas where years of irrigation, poor drainage and imbalanced fertilizer use have caused a buildup of salt in the soil.

“We need to use salt-marsh plants to supplement agricultural needs of the world,” Gallagher says. “We can use this type of plant to meet both animal and human needs by growing them, not in the marsh, but in upland areas that have salty soils or that can be irrigated with nearby seawater.”

“By planting salt-marsh plants developed as crops, we can restore saline soil to productivity,” Seliskar says, adding that saltwater can be used to irrigate such crops, conserving freshwater supplies for direct human and animal use. Researchers are interested in how the biology of haloyphytes differs from that of plants damaged by salt, as well as the nature of their ecological role in their native habitats.

Salt-marsh plant selections from the Halophyte Biotechnology Center are being studied and tested in locations around the world, including Thailand, China and Egypt.