Crop Wild Relatives in Genebanks
Gayle M. Volk, USDA-ARS National Laboratory for Genetic Resources Preservation, 1111 S. Mason St., Fort Collins, Colorado, 80521<EMAIL_ADDRESS>Christopher Richards, USDA-ARS National Laboratory for Genetic Resources Preservation, 1111 S. Mason St., Fort Collins, Colorado, 80521
Christina Walters, USDA-ARS National Laboratory for Genetic Resources Preservation, 1111 S. Mason St., Fort Collins, Colorado, 80521
Hannes Dempewolf, Global Crop Diversity Trust, Platz Der Vereinten Nationen 7, 53113 Bonn, Germany
Patrick Byrne, Dept. of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado 80523
Outline
- Introduction
- Capturing diversity in situ and ex situ
- Conservation targets
- Considerations for collecting plant genetic resources
- Retaining diversity in genebanks
- International efforts to conserve crop wild relatives
- Conserving seeds of wild species
- References
- Acknowledgments
1. Introduction
Plants can be conserved in either in situ (natural habitat) or ex situ (genebanks, botanic gardens, etc.) conditions. There is an incentive to conserve wild species in genebanks, particularly as natural habitats are becoming depleted. Plant genebanks maintain genetic resources in different forms, including seeds and actively growing plants, depending upon the growth characteristics and genetic composition of the conserved materials. Genebanks must capture the desired conservation target and retain it indefinitely in ex situ conditions. This critical function of genebanks may be particularly challenging for accessions (samples) that represent wild species.
2. Capturing diversity in situ and ex situ
In situ conservation is the preservation of plants (specific individuals or populations) in their natural habitat (Bretting and Duvick, 1997; Dulloo et al., 2010). This may occur when preserves (national parks, designated areas, etc.) are established to conserve species in natural areas, including the land, vegetation, and animals. Similarly, on-farm conservation is when a farmer chooses to grow local varieties. In situ conservation has the benefit of preserving plants in their ecosystem and it retains the relationships between the plants, soil, microbes, pollinators, and climate. A primary disadvantage is that plants that are maintained in situ are at risk if there are environmental or biotic threats. These plants are also not readily available for research (other than primarily in an ecological context) and populations may disappear as a result of changing habitats.
Figure 1. Wild Malus sieversii apples protected in a national park in Kazakhstan. Photo credit: Gayle Volk.
Ex situ conservation is the preservation of plants (specific individuals or populations) in a non-native setting. This includes genebanks (in a field or seedbank), botanic gardens, as well as plant breeding programs. Plants that are conserved ex situ have the advantage of being less vulnerable to environmental and biotic threats, are usu