Celebrating Wildflowers News
Complementary Conservation of Wild Cranberry
Food security for the world’s growing human population is one of the most pressing issues of our time. Plant breeders need diverse resources, working to improve crops so that they can feed people in the most efficient, effective and sustainable manner. Among these resources are the wild plants that are related to crop plants, or crop wild relatives (CWR). CWR tend to have greater genetic variability than crop plants, and their genetic identities differ from those of crop plants in significant ways. Wild species evolve in response to changes in environmental conditions, pests, pathogens and predators. When problems arise with crop plants, the solutions may be found in the genes of wild relatives.
The Forest Service and the Agricultural Research Service (USDA-ARS) are uniquely positioned to cooperate with the complementary conservation of crop wild relatives native to the United States. The Forest Service has the responsibility for managing 193 million acres of National Forest System lands in 43 states. The USDA-ARS manages the U.S. National Plant Germplasm System (NPGS), which has the responsibility to collect, maintain, distribute, evaluate, and preserve genetic resources of plant species of interest to the United States. The two agencies are taking advantage of their complementary missions in a program to conserve CWR both in their natural environments (in situ) and in gene banks (ex situ) where they are available for use in research, breeding, and restoration.
Wild cranberries, from which cultivated cranberries are derived, have been chosen as the first test case for the joint program. Populations of cranberry occur across the northeastern and north central United States and as far south as Tennessee and North Carolina. The wild populations contain genetic diversity that may not be found in the cultivated varieties and could be important in breeding new varieties that can adapt to a changing climate and other environmental stresses.
Cranberry Glades, Monongahela National Forest, West Virginia.
Ned Garvey and Karen Williams, with the ARS National Germplasm Resources Laboratory in Beltsville, Maryland, and Larry Stritch, with the Forest Service in Washington, DC, recently visited wild cranberry bogs on National Forests in West Virginia and Virginia. They tested and refined protocols developed to measure genetic diversity of the cranberry populations and to determine the fitness of populations as in situ genetic reserves. Forest Ecologist Kent Karriker, from the Monongahela National Forest, and Botanist Fred Huber of the George Washington National Forest, provided critical support by guiding the party to the locations, and providing historic and floristic information.
Karen Williams and Ned Garvey, Agricultural Research Service National Germplasm Resources Laboratory, at Spring Pond, George Washington National Forest, Virginia.
Kent Karriker, Forest Ecologist, Monongahela National Forest, West Virginia.
- The strategy and protocols developed for the complementary conservation of wild cranberry were tested and subsequently modified.
- Leaf tissue was collected and sent to Juan Zalapa at the ARS Cranberry Genetics and Genomics Laboratory in Madison, Wisconsin, for molecular analysis of inherent genetic variability. Results from microsatellite SSR testing of 11 unique primers across all samples showed that the V. macrocarpon and V. oxycoccos gave consistent and expected microsatellite alleles for both species. There were four unique genotypes identified in the V. macrocarpon samples: three unique genotypes identified in the George Washington National Forest and one in the Monongahela National Forest. Six unique V. oxycoccos genotypes were detected.
- Fruits were collected from one site on the George Washington National Forest, Virginia. Seeds from these fruits were sent to Kim Hummer, curator of the National Clonal Germplasm Repository in Corvallis, Oregon, a component of the U.S. National Plant Germplasm System, for ex situ conservation and distribution to researchers and educators.
- Herbarium vouchers were collected and sent to the Herbarium at the U.S. National Arboretum.
Over the next several years wild populations of native cranberries (Vaccinium macrocarpon and V. oxycoccos) will be sampled from throughout their ranges and genetic variation will be measured through molecular analysis of the leaf tissue. Seeds from these populations will be maintained in the medium and long-term ex situ collections of the U.S. National Plant Germplasm System and the U.S. Forest Service will preserve specific populations in situ.
Vaccinium macrocarpon, Green Pond, George Washington National Forest, Virginia.
Vaccinium oxycoccos, Cranberry Glades, Monongahela National Forest.
Other crops with wild relatives in the United States include sunflower, blueberry, grape, pecan, squash, quinoa, wild rice, strawberry, and many more. It is anticipated that in the future all native United States plants important to global food security growing on land managed by the federal government will be preserved both in situ and ex situ, optimizing conservation practices and increasing the availability of essential genetic resources.
Fred Huber, U.S. Forest Service, at Green Pond, George Washington National Forest, Virginia.