Salazar, R., Louwaars, N., and Visser, B. (2007). Protecting Farmers' New Varieties: New Approaches to Rights on Collective Innovations in Plant Genetic Resources. World Development, 35(9), pp. 1515-1528. 

This article documents how modern varieties developed in the formal sector have gradually replaced landraces as a source of diversity for many small-scale traditional farmers. However, this development has not done away with farmer-breeding, which is vital in traditional agriculture.

This knowledge is of great importance when designing plant breeders and farmers' rights, in order to ensure food security and genetic diversity. The major challenges are to warrant the recognition of the collective innovation and breeding efforts of farmers, to allow access to relevant genetic resources, and to keep these materials freely available for use and further breeding - while at the same time ensuring effective benefit sharing, the authors conclude.