Global Crop Diversity Trust

A Foundation for Food Security

Pre-breeding

Modern crop varieties, on which our present and future food security depend, are the result of years of careful crossing and selection of highly refined, generally genetically uniform material. Some of these varieties have been so successful that they have been adopted over large areas. This has the drawback, however, of leaving the crop vulnerable to new pests, diseases and climatic conditions, not to mention changes in consumer preferences. So breeders’ work never ceases, and they are always on the lookout for new sources of useful traits for new challenges, and indeed old challenges against which progress has slowed.

There are many sources of resistance to pests and diseases, and other useful traits, within the pool of wild and weedy species related to crops. These species harbor diversity that has remained untapped during domestication – the process during which early farmers started growing and changing the crops we know today. The use of such species in modern crop improvement can be challenging, as they typically contain a lot of undesirable traits, along with their interesting genes. Wild species, for instance, may not have genes for high yield, even while providing traits for pest resistance. The trick lies in incorporating the most useful characteristics while minimizing disadvantageous traits hitching a ride. While recognizing the potential value of wild species and farmer heirloom varieties, plant breeders are often reluctant to use these resources in breeding programs involving their highly bred cultivars produced by so many years of careful refinement.

Fortunately, some publicly funded plant breeders and researchers have traditionally bridged the gap between wild genetic resources and those plant breeders working with advanced, elite cultivars. They do this through base-broadening and pre-breeding programs. These aim to reduce genetic uniformity in crops through the introduction of new diversity, as well as to increase yields, resistance to pests and diseases, and quality traits.

Pre-breeding is a vital step in the link between conservation and use of plant genetic resources. Unfortunately, reduced funding of public breeding programs over recent years, combined with a shift in public funding toward more basic research, has seriously limited current work in pre-breeding, particularly in national agricultural programs.

Recognizing the relative lack of support for pre-breeding, the Trust has included substantial support of pre-breeding efforts in the framework of the Trust’s initiative to conserve, collect and use crop wild relatives. Scientists at the Trust are in the process of organizing expert consultations involving a diversity of pre-breeding specialists from many different countries and institutions. The objective is to determine how best to utilize wild relatives in pre-breeding programs for a set of key crops. Over the coming years, the Trust will then support specific pre-breeding work aiming to incorporate wild diversity in breeding programs focusing on adaptation to changing climates.

The Trust also collaborated with the Global Partnership for Plant Breeding Capacity Building to support selected pre-breeding efforts worldwide. It has funded training courses and training materials on pre-breeding, and provided grants for pre-breeding projects which address pest and disease issues, enhance yield, and improve nutritional quality.

Investment in pre-breeding helps to maintain the link between the conservation of diverse crop genetic resources and the modern breeding programs that produce varieties that address farmers’ ever-changing needs.