Plant breeders around the world are growing increasingly dependent on using wild species of crops to help alter modern versions in order to increase yields and/or combat climate change. However, a new study indicates some wild species are not being protected in gene banks, which could be devastating for future plant breeding developments.

The study, published in the journal Nature Plants, is the first global survey undertaken of the distribution and conservation of wild species. The study found that 1,076 wild relatives of 81 crops were insufficiently safeguarded. Up to 300 species could not even be located in any gene bank.

Plant breeders have turned to gene banks to use these wild relatives to do their research because wild relatives are the progenitors and kin of domesticated crop species. Wild relatives offer plant breeders a secret weapon. And now, their research could be threatened if gene banks are unable to acquire wild relatives.

“There are big gaps for many crops and in many regions,” said Nora Castañeda-Álvarez, a scientist at the International Center for Tropical Agriculture (CIAT). “It’s now clear that scientists around the world are in a race against time to collect and conserve many of the most important plant species for future food security.”

Finding and conserving wild relatives has become a priority thanks to the United Nation’s Sustainable Development Goals. The new study even indicates that finding, collecting and preserving crop wild relatives will require a massive global effort. One effort is already underway in 17 countries, and it’s considered to be the largest to day of collecting wild gene pools. Its focus is on collecting the wild relatives of 29 of 64 crops that are listed in an annex to the International Treaty on Plant Genetic Resources for Food and Agriculture. Unfortunately, crops such as the wild relatives of peanut, asparagus or lettuce, are not on the list to be collected.

One of the challenges of securing more crop wild relatives is that many are in habitats that are threatened by urbanization, pollution, deforestation, climate change and war.

The authors found that the wild relatives of important food security crops like banana and plantain, cassava, sorghum and sweetpotato are all in urgent need of collection and conservation, along with those of pineapple, carrot, spinach, and many other fruits and vegetables. Even for the wild relatives of vital staples like rice, wheat, potato, and maize—which tend to be better represented in genebanks—there are still significant gaps in the collections.

In addition, they flagged the fact that some crops’ wild relatives marked as high priority for collection and conservation are under threat, from war and civil strife in places like Syria and Afghanistan and from changes in land use, such as deforestation, in southeast Asia.

“The overall level of exposure to risk is really troubling,” said Colin Khoury, co-author and also a scientist at CIAT. “The world’s food supply is in a precarious position of depending on too few crop plant species. For every crop wild relative (CWR) that’s not conserved in a genebank and available for research, it means there is one less option for plant breeders to improve the resilience of the food crops we rely on so much. Our findings give us the clearest idea yet of which plants are missing and where in the world we need to search for them.”

Ruth Eastwood, Crop Wild Relatives Project coordinator at Royal Botanic Gardens (RBG), Kew, agrees. “Although a lot of experts have known about gaps for individual crops, this is the first time we’ve had a comprehensive global overview that is widely available.”

Key findings of the study include:

  • 29 percent of the total, or 313 wild relative plant species analyzed, are completely missing from the world’s genebanks.
  • Additionally, 257 (23.9 percent) of species are represented by fewer than 10 samples having been collected for each, leaving out a substantial amount of potentially important plant diversity.
  • More than 70 percent of the total crop wild relative species are in urgent need of collection and conservation to improve their representation in genebanks.
  • More than 95 percent are insufficiently represented in regard to the full range of geographic and ecological variation in their native distributions.
  • The most critical collecting gaps occur in the Mediterranean and Near East; western and southern Europe; Southeast and East Asia; and South America.