What the wild things do: The use of crop wild relatives in public international breeding programs and implications for conservation

Abstract

Wild species related to agricultural crops make agricultural systems around the world more resilient. Crop wild relatives (CWR) represent the largest pool of genetic diversity from which to draw when new variation for desired traits is required in domesticated varieties. They contribute towards the development of new crop varieties, particularly those adapted to predicted climate change scenarios. Although CWR are generally inedible, are not used for fuel or fodder, and very few have documented medicinal properties, they support global food production systems from behind the scenes. Placing an economic value on their contributions has had the effect of pulling CWR onto centre stage, and wild species are in fact beginning to garner international attention. The question is whether or not estimating their value in terms of the development of new varieties adequately represents their total value, and in particular the adaptive capacity they provide to agroecosystems. What are the implications of exclusively measuring their direct use value? This thesis explores the space where agrobiodiversity, climate change, advanced crop breeding and economics meet in order to address this question.

Two distinct but related research questions are discussed in sequence. The first asks: to what extent are CWR being used today within crop improvement programs under the auspices Consultative Group on International Agricultural Research (CGIAR)? The main findings are that CWR are being used to a greater extent today than ever before, and that a positive trend is likely to continue in light of both technological advancements and intensifying environmental pressures. Research findings are relevant to the conservation community advocating for increased investment and will help inform policy decisions involving trade-offs and priority setting among conservation objectives.

The second question arises in light on the first: what are the implications of increased use of CWR in breeding? Implications include increased conservation investment and an emerging conservation paradigm that is focused exclusively on facilitating future use of selected species closely related to socio-economically important crops rather than the breadth of diversity that exists today. This diversity is threatened with extinction by range of environmental and anthropogenic forces. The positive feedback between use and conservation will continue to the extent that required genetic variation is available.

This thesis argues that increased use will likely not incite sufficient levels of conservation. Conservation is a reflection of the way humans value biodiversity. CWR are valued for their instrumental use in crop breeding but less so for the resilience they lend to agroecosystems, and not at all for their intrinsic value. Understanding the dynamic between valuation and conservation is useful for making projections into the future and will help inform course corrections at the relatively early stage of the conservation investment game. Policy recommendations stem from a greater recognition of the resilience value provided by the breadth of CWR diversity, agrobiodiversity more broadly defined, and the importance of conserving it both in situ and ex situ. The availability of genetic variation for agricultural crops in the long term and by extension any meaningful contributions towards achieving sustained food production, depend upon it.