International Biodiversity Day is here, and CGIAR brings us news that climate change threatens the wild relatives of cultivated potatoes and peanuts. The CGIAR study warns that 61% of wild peanut and 12% of wild potato species could be made extinct over the next half century. This poses a problem for plant breeders and GM crop producers alike. Wild relatives are a vital source of genetic diversity for crop improvement and if that pool of resources is diminished, genes which confer resistance to pathogens for example, are lost.
Andy Jarvis of CGIAR explains "The vulnerability of a wild plant to climate change can depend on its ability to adapt by, for example, extending its range as warming in its native regions becomes too hot to handle. One reason wild peanut plants appear to be so vulnerable to climate change is they are largely found in flat lands and would have to migrate a long way to reach cooler climates, a predicament exacerbated by the fact that peanuts bury their seeds underground, a meter or less from the parent plant. That limits the speed at which seeds can move into more favorable climates. By contrast, plants in mountainous locations could theoretically survive by extending their range slightly up a slope, even by only a few meters, to find cooler weather."
The usefulness of wild relatives for crop improvement has long been known. Modern hexaploid wheat is a famous example, where cross breeding of related grass species has produced a domesticated and widely cultivated crop. A recent discovery in the genetics of potato relatives, described here in an abstract from in the CAB Abstracts database, holds the promise of resistance to many races of the feared Phytophthora infestans late blight. Until recent weeks a five-year trial release of genetically modified potatoes carrying this gene was scheduled to take place in Yorkshire. That trial has now been cancelled due to the fears of local beekeepers for the integrity of their honey products. Anti-GM campaign group GM Freeze support the cancellation both on behalf of beekeepers and on the grounds that "There are concerns that such toxins from the wild relative [potatoes are members of the nightshade family] may be carried into the GM potatoes inadvertently and thus enter the food chain". Whatever your views on the potential reductions in chemical load on the environment that would result from blight-resistant potato crops, versus the theoretical impacts on bee colonies and human health, it is clear from today’s CGIAR announcement that time could be running out to make use of the genetic material of wild relatives by conventional breeding or GM means.