Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 92

Breeding objectives depend on the species and the intended use of the cultivar to be developed. Over the years, new (alternative) species have been identified to address some traditional needs in some parts of the world. By the same token the traditional uses of some species have been modified. For example, whereas corn continues to be used for food and feed in many parts of the world, corn has an increasingly industrial role in some industrialized countries (e.g. ethanol production for biofuel). Yield or productivity, adaptation to production environment, and resistance to biotic and abiotic stresses will always be important. However, with time, as they are resolved, breeders shift their emphasis to other quality traits (e.g. oil content, or more specific consumer needs like low linolenic content). Advances in technology (high throughput, low cost, precision, repeatability) have allowed breeders to pursue some of the challenging objectives that once were impractical to do. Biotechnology, especially recombinant DNA technology, has expanded the source of genes for plant breeding in the last half decade. Also, the increasing need to protect the environment from degradation has focused breeders' attention on addressing the perennial problem of agricultural sources of pollution.