Principles of Plant Genetics and Breeding

Section 8
Cultivar release and commercial
seed production
Chapter 23 Performance evaluation for crop cultivar release
Chapter 24 Seed certification and commercial seed multiplication
Chapter 25 International plant breeding efforts
Chapter 26 Emerging concepts in plant breeding
Plant breeding is often a very lengthy process, lasting over a decade in many cases. After the plant breeder
assembles and organizes variability into a new genetic matrix, the next and very crucial stage is to decide which
of the many genotypes to release as a cultivar for use by crop producers. This step involves the evaluation of candidate
genotypes under various conditions, including those under which the crop will be produced. The plant
breeder resorts to field plot techniques to assist in experimental design and conduct, as well as for the evaluation
of genotypes to determine the most promising for release. Computers are often needed to handle the complex
analysis that considers not only the final yield, but also yield stability. After identifying the most promising
genotype, the material is submitted for seed increase, certification according to criteria specific to the particular
crop, and then release for sale.
Whereas seed production and cultivar development are well organized and highly commercialized enterprises
in developed economies, farmers in developing countries often depend on low-yielding farmer-developed
cultivars for planting. Unable to afford the high cost of improved seed marketed by multinational companies,
international agricultural centers are a major source of improved seed for farmers in poor countries. Further,
plant breeders are regularly seeking new ways of cultivar development for increasing the productivity of farmers
and meeting consumer demands. Emerging concepts in plant breeding and the role of international agricultural
centers in global cultivar development are also discussed in this section.