Rethinking crop genetic resource conservation

A worldwide system of crop germplasm conservation has been developed around ex situ preservation. This system is based on a dual mandate of conservation and development, and it has largely ignored the farming systems that produce germplasm. A revisionist critique of the existing system is presented. Problems of the current strategy include incomplete collections, loss within these collections, isolation from evolutionary processes, and budgetary constraints. In situ conservation offers an alternative to current methods especially if conservation rather than development is the priority. The concept of genetic erosion is discussed and evaluated in light of recent evidence of uneven change in areas of crop diversity. Farmers in many parts of the world are conserving traditional varieties even as they modernize and adopt improved varieties. This pattern is illustrated by reference to Asian rice agriculture. A new approach to conservation is needed that builds a collaborative program between farmers, crop scientists, ecologists, biogeographers, and social scientists. A first step is to analyze farming systems that already conserve traditional crop varieties.