Crop wild relatives (CWRs), as the name suggests, are the wild cousins of our modern domesticated crop species. For every watermelon, bok choi, and ear of corn we grow today, there was a Kordofan melon, a field mustard, and a teosinte that served as its wild ancestor. Over thousands of years, humans bred them from low-yielding wildflowers and grasses into the highly productive crops that feed our world.
While we aren’t doing much straightforward domestication these days (though some researchers are pursuing it), crop wild relatives provide an invaluable service to modern plant breeding and agriculture. Populations of CWRs are much more genetically diverse than their domesticated counterparts, and often, they can provide genetic material that is absent but useful in domesticated populations. One successful program crossed the species Manihot glaziovii with its cousin cassava, an important food crop in Latin America, Sub-Saharan Africa, and South and Southeast Asia. These crosses were resistant to several devastating diseases, such as the cassava mosaic virus. Introducing these new varieties to farmers has the potential to greatly increase yields in some areas, a stunning success critical for food and nutritional security.
Unfortunately, wild populations of CWRs are under serious threat worldwide. In the United States, one study found that half of CWR species may be endangered, and nearly 60% require “urgent priority for further action.” CWRs face complex challenges, from the loss of their habitat to the erosion of genetic variability between and within populations. Supporting agricultural biodiversity is critical for future food security, and conserving these populations is the first step.
As with anything in conservation, the issue comes down to money. CWR conservation is largely underfunded, even for highly profitable and important crops such as corn and bananas. This problem falls into the free rider problem. If one organization, company, or country funded the conservation of CWR for a particular crop, the benefits of that investment would be shared by all, even those who didn’t pay in the first place. Additionally, it simply is not profitable to conserve genetic diversity for the day you might need it when today that money can be invested into something more immediately profitable. Long-term investments don’t function in a short-term-focused economy.
Fortunately, we have a mechanism in the US that could potentially solve this problem: the checkoff. Commodity checkoff programs are designed to mitigate the free rider problem. For each unit of a commodity sold, say a carton of eggs, a small fee is charged, which goes to the checkoff. That money is then used to finance marketing and research programs, which are difficult for individual companies to do since their competitors would benefit from the investment since commodities are products that are difficult to differentiate from one another. These programs are where campaigns such as ‘The Incredible, Edible Egg” commercials come from. It solves the free rider problem by compelling investment from every producer toward promotional activities for the industry.
This model has the potential to mobilize funding towards CWR conservation. To illustrate how this could work, let’s look at blueberries. Native to North America, they have a number of relatives on this continent, one of them being Vaccinium myrtilloides, also known as the sourtop blueberry. A wild shrub, it is considered endangered in several states and threatened in others. In this scenario, the checkoff for blueberries, the Highbush Blueberry Council, would finance either the collection of wild populations for storage in a university or USDA genetic repository or fund the direct preservation of the land the population sits on to protect it.
Checkoff programs could theoretically begin spending money on CWR conservation from their mandate to support research. However, opposition from farmer and industry groups would likely be high. Since producers elect checkoff leadership, boards often support short-term marketing pushes to create as many avenues for sales as possible. Long-term investments in research normally focus on exploring a specific crop’s nutritional benefits, improving production practices’ efficiency, managing crop diseases and pests, and finding new industrial and culinary uses for crops, livestock, and byproducts. All investments that directly correlate with increased profitability. Introducing a legislative or executive directive could compel conservation investment, however.
Another possible sticking point comes back to the free rider problem. Conservation of CWRs is inherently beneficial to any nation that grows that crop. Conserving raspberry relatives would benefit other raspberry-producing nations, such as Poland, Serbia, and Mexico, even if they don’t pay into the program. An associated issue is that most CWR populations aren’t in the United States, so conservation dollars would largely be spent in other nations. For example, potato producers could send money to conservation efforts in Peru and Chile, which, while undeniably a good investment for the industry, would likely not be popular among domestic farmers. Conservation efforts could be spent collecting samples of wild populations, bringing them back to the US, and storing them in seed banks here, but this is less effective as a conservation strategy, where conserving whole populations is best for ensuring genetic diversity.
One final barrier to this idea is the relative lack of checkoff programs. There are only 23 checkoff programs. Some focus on livestock (though these could similarly support rare breed conservation) or nonagricultural commodities such as propane. This leaves only 13 federal checkoff programs focused on timber products and crops. Many crops with wild relative populations in the US, such as grapes or pecans, lack a checkoff program that could coordinate investments.
Mobilizing funds for the proper conservation and utilization of crop wild relative conservation is quite difficult. Exploring available options to coordinate investment by industry actors is one potentially strong strategy to pursue this goal. While there are significant barriers and limitations to utilizing checkoff programs towards this end, exploring it could prove fruitful for those advocating for increased investment in this area.
References
Amelework, A.B., and M.W. Bairu. 2022. Advances in Genetic Analysis and Breeding of
Cassava (Manihot esculenta Crantz): A Review. Plants (Basel) 11(12): 1617. doi:
10.3390/plants11121617.
Dempewolf, H., G. Baute, J. Anderson, B. Kilian, C. Smith, et al. 2017. Past and Future Use
of Wild Relatives in Crop Breeding. Crop Science 57(3): 1070–1082. doi:
10.2135/cropsci2016.10.0885.
Khoury, C.K., D. Carver, S.L. Greene, K.A. Williams, H.A. Achicanoy, et al. 2020. Crop wild
relatives of the United States require urgent conservation action. Proceedings of the
National Academy of Sciences 117(52): 33351–33357. doi: 10.1073/pnas.2007029117
