Imagine this: a scraggly little plant by the side of the road could one day blunt the impact of climate change on our food security and nutrition. That plant is a crop wild relative: a wild species that is genetically related to a cultivated crop. Crop wild relatives evolve alongside pests and diseases, developing traits that help them survive in the wild. Farmers have understood the value of crop wild relatives since the earliest days of agriculture, planting them together with their crops to encourage the natural crossing of useful traits. Professional plant breeders followed suit in the late 18^th century, when they began to use crop wild relatives to transfer disease resistance to cultivated varieties. Since then, wild relatives have been used as a source of genes for insect, virus, fungus and nematode resistance as well as for improving nutritional quality and yield and helping crops adapt to poor environments.

Crop wild relatives in global policy

The importance of conserving crop wild relatives was first raised in technical meetings of the Food and Agriculture Organization of the United Nations (FAO) back in the 1960s, when countries were beginning to recognize the value of agricultural biodiversity for crop improvement. In situ conservation, which enables the genetic resource to continue to evolve under natural conditions, has generally been the strategy of choice for crop wild relatives, backed up by ex situ conservation, which greatly facilitates their study and use.

Since its creation in 1983, the main forum for policy-making on agricultural biodiversity has been the FAO Commission on Genetic Resources for Food and Agriculture. Over the last 30 years, the Commission has progressively adopted a number of international policy instruments concerned with conserving agriculture biodiversity and crop wild relatives in particular.

The International Treaty on Plant Genetic Resources for Food and Agriculture – adopted in 2001 – urges both ex situ and the exchange of crop genetic resources and in situ conservation of wild relatives, including in protected areas. Under the Treaty, over 130 countries committed to sharing the genetic resources of the crops most critical to global food security to produce new, more productive crop varieties. For this purpose, more than 10 000 accessions of crop wild relatives held by CGIAR genebanks are immediately available under the Treaty to researchers and breeders worldwide.

In 2010, the Second State of the World Report on Plant Genetic Resources for Food and Agriculture cited the ongoing need to improve the diversity coverage in ex situ collections, including of crop wild relatives. As conserving crop wild relatives is not only a global priority but also a responsibility for individual countries, the Report also warned that most countries lacked enabling policies, legislation and procedures for collecting wild relatives and for protecting them in situ. The Second Global Plan of Action for the Conservation and Sustainable Utilization of Plant Genetic Resources– adopted in 2011 – noted that crop wild relatives had received little conservation attention compared to their potential for breeding and highlighted this as a priority area for action.

A draft Global Strategy for the Conservation and Use of Crop Wild Relatives, presented to the First International Conference on Crop Wild Relatives in 2005 by a range of government and non-governmental agencies, sought to support the development of national and regional strategies for the management of wild relatives through in situ and ex situ conservation and sustainable use; eleven years later only a few countries have approved and implemented national strategies. Regional approaches have also been explored. A regional strategy for Europe, adopted in 2008, did set some ambitious conservation targets for crop wild relatives: “60 per cent of species of European conservation priority plant and fungal species, including crop wild relatives, (is) conserved in situ by 2014 through the implementation of national strategies for conserving priority species;” and “25 European crop wild relative genetic reserves (are established) covering the major hotspots of species and genetic diversity. “

Agriculture is nor alone in its efforts to protect and mobilize the diversity in CWRs. The global environmental community has also recognized the value of CWR. In 2010, the Conference of the Parties to the Convention on Biological Diversity (CBD) adopted a Strategic Plan for Biodiversity, which – among others – set the following targets: “by 2020 the status of crop and livestock genetic diversity in agricultural ecosystems and of wild relatives has been improved” and “in situ conservation of wild relatives of crop plants (has been) improved inside and outside protected areas.” Target 9 of the CBD’s Global Strategy for Plant Conservation 2011–2020 is that “70 per cent of the genetic diversity of crops including their wild relatives and other socio-economically valuable plant species conserved.”

CWR are also placed in the global development discourse. The United Nations Sustainable Development Goals states its aims to “by 2020 maintain genetic diversity of seeds, cultivated plants, farmed and domesticated animals and their related wild species, including through soundly managed and diversified seed and plant banks at national, regional and international levels, and ensure access to and fair and equitable sharing of benefits arising from the utilization of genetic resources and associated traditional knowledge as internationally agreed.”

Despite the widespread recognition of the importance of conserving crop wild relatives in multiple global fora, more progress is desirable on the ground. Such species have been seen by some sectors as more problematic to conserve ex situ than are seeds of major food crops for which a great deal is known. Information about crop wild relatives is fairly scant and, where it does exist, is dispersed among different national and international organizations that do not share information on a regular basis. There are also political and infrastructural problems that limit effective in situ conservation. Few national conservation initiatives target crop wild relatives specifically. Effective conservation often requires collaboration between different ministries, agencies or institutions in countries where there is neither a tradition of inter-sectoral collaboration nor a history of inter-agency cooperation.

Analyzing and filling conservation gaps

New impetus has recently come from the research community. The ‘Adapting Agriculture to Climate Change’ project has produced a study which investigates gaps in conserving in genebanks the wild relatives of an updated list of 81 crops that are critical for food security, such as plantain, cassava, sweet potato and millet, and fruits and vegetables like apples, bananas, carrots and spinach.

What the team of researchers discovered is alarming: 95% of the 1076 wild relative species analyzed were insufficiently represented in genebanks with regard to the full range of diversity in their native distributions, with 29% totally missing from collections and another 24% represented by fewer than ten samples. The conclusion: over 70% of crop wild relative species are in urgent need of rescuing through collecting on the field, and long term conservation. The most critical collecting gaps occur in the Mediterranean and Near East; Western and Southern Europe; Southeast and East Asia; and South America. The study warned that some of the wild relatives that are high priorities for conservation are under threat from war and civil strife in countries 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 of the study and a scientist at CIAT. “The world’s food supply is in a precarious position of depending on too few crop plant species. For every wild relative that is not conserved in a genebank and available for research, there is one less option for plant breeders to improve the resilience of the food crops we rely on so much.”

The findings of the gap analysis are featured in the groundbreaking new report – The State of the World’s Plants – launched by Kew at an international conference on the 11th and 12th May 2016.