D.A. Cooke and R.K. Scott Sugar beet is one of just two crops (the other being sugar cane) which constitute the only important sources of sucrose - a product with sweeten ing and preserving properties that make it a major component of, or additive to, a vast range of foods, beverages and pharmaceuticals. Sugar, as sucrose is almost invariably called, has been a valued compo nent of the human diet for thousands of years. For the great majority of that time the only source of pure sucrose was the sugar-cane plant, varieties of which are all species or hybrids within the genus Saccharum. The sugar-cane crop was, and is, restricted to tropical and subtropical regions, and until the eighteenth century the sugar produced from it was available in Europe only to the privileged few. However, the expansion of cane production, particularly in the Caribbean area, in the late seventeenth and the eighteenth centuries, and the new sugar-beet crop in Europe in the nineteenth century, meant that sugar became available to an increasing proportion of the world's population.

Plant Breeding Reviews presents state-of-the-art reviews on plant genetics and the breeding of all types of crops by both traditional means and molecular methods. Many of the crops widely grown today stem from a very narrow genetic base; understanding and preserving crop genetic resources is vital to the security of food systems worldwide. The emphasis of the series is on methodology, a fundamental understanding of crop genetics, and applications to major crops.

While preparing the first edition of this textbook I attended an extension short course on writing agricultural publications. The message I remember was "select your audience and write to it. " There has never been any doubt about the audience for which this textbook was written, the introductory course in crop breeding. In addition, it has become a widely used reference for the graduate plant-breeding student and the practicing plant breeder. In its prepa ration, particular attention has been given to advances in plant-breeding theo ry and their utility in plant-breeding practice. The blend of the theoretical with the practical has set this book apart from other plant-breeding textbooks. The basic structure and the objectives of the earlier editions remain un changed. These objectives are (1) to review essential features of plant re production, Mendelian genetic principles, and related genetic developments applicable in plant-breeding practice; (2) to describe and evaluate established and new plant-breeding procedures and techniques, and (3) to discuss plant breeding objectives with emphasis on the importance of proper choice of objec tive for achieving success in variety development. Because plant-breeding activities are normally organized around specific crops, there are chapters describing breeding procedures and objectives for the major crop plants; the crops were chosen for their economic importance or diversity in breeding sys tems. These chapters provide a broad overview of the kinds of problems with which the breeder must cope.