Vital Genetic Resources For Resisting Drought, Pests Jeopardised By Climate Change

Medical News Today: Wild relatives of plants such as the potato and the peanut are at risk of extinction, threatening a valuable source of genes that are necessary to boost the ability of cultivated crops to resist pests and tolerate drought, according to a new study released by scientists of the Consultative Group on International Agricultural Research (CGIAR). The culprit is climate change, the researchers said.

According to the study, in the next 50 years as many as 61 percent of the 51 wild peanut species analyzed and 12 percent of the 108 wild potato species analyzed could become extinct as the result of climate change. Most of those that remained would be confined to much smaller areas, further eroding their capacity to survive. The study also examined wild relatives of cowpea, a nutritious legume farmed widely in Africa. It found that only two of 48 species might disappear. However, the authors predict that most wild cowpeas will decline in numbers because climatic changes will push them out of many areas they currently inhabit.

"Our results would indicate that the survival of many species of crop wild relatives, not just wild potato, peanuts and cowpea, are likely to be seriously threatened even with the most conservative estimates regarding the magnitude of climate change," said the study's lead author, Andy Jarvis, who is an agricultural geographer working at two CGIAR-supported centers - the Colombia-based International Center for Tropical Agriculture and Bioversity International, with headquarters in Rome. "There is an urgent need to collect and store the seeds of wild relatives in crop diversity collections before they disappear. At the moment, existing collections are conserving only a fraction of the diversity of wild species that are out there."

…Though not apparent to the average consumer, the wild relatives of crops play an important role in food production. All food crops originated from wild plants. But when they were domesticated, their genetic variation was narrowed significantly as farmers carefully selected plants with traits such as those related to taste and appearance as well as to yield. When trouble arises on the farm -attacks by pests or disease or, more recently, stressful growing conditions caused by climate change - breeders tend to dip back into the gene pool of the robust wild relatives in search of traits that will allow the domesticated variety to overcome the threat.

"The irony here is that plant breeders will be relying on wild relatives more than ever as they work to develop domesticated crops that can adapt to changing climate conditions," said Annie Lane, the coordinator of a global project on crop wild relatives led by Bioversity International. "Yet because of climate change, we could end up losing a significant amount of these critical genetic resources at precisely the time they are most needed to maintain agricultural production.