Scientific breeding in the twentieth century greatly accelerated wheat?s evolution, producing high-yielding varieties that helped avoid famine in many developing countries. Emerging scientific tools hold promise for identifying and tapping new, useful genetic diversity within wheat?s primary and secondary gene pools and, through genetic engineering, beyond.The book describes generally how policies affect wheat genetic diversity; it looks at historical changes in wheat genetic diversity, as policy and priorities have evolved; it identifies factors that explain changes and differences in spatial diversity; and finally, it analyzes the productivity impacts of changes in diversity. Chapters define various types of crop genetic diversity and ways to measure them, framing the definitions and metrics in the contexts for which they are most relevant.

Role of Economics in Crop Genetic Diversity; Conceptual Framework for Crop Diversity: Concepts and Measurement; Agricultural Policy, the Wheat Economy, and Crop Diversity in China; Policy Influences on Wheat Genetic Diversity in Australia; Breeder Demand for and Utilization of Wheat Genetic Resources in Australia; Wheat Diversity Changes in China, 1982�1997; Wheat Diversity Changes in Australia, 1965�1997; Explaining Spatial Diversity in Wheat in Australia and China; Determinants of Wheat Diversity in Chinese Household Farms; Wheat Diversity and Total Factor Productivity in China; Cost Function Analysis of Wheat Diversity in China; Overview and Policy Implications