The role and basics of computer simulation in support of critical decisions in plant breeding

A number of crucial decisions face the plant breeder before any field activities directed to crop genetic improvement are actually initiated, primarily related to choice of parents and breeding strategy options. Because of the impact, the complexity of these decisions, and the cost of implementing multiple options, computer simulation can be an important resource for the modern breeder. To maximize utility, the simulation tool must be based on effective models of the genome, the breeding process, and other 'processes' involved in genetic recombination, identification, and production of new cultivars. Additionally, the statistical methodology employed has ramifications for predicting performance and breeding outcome. The objective of this work is to highlight the role of computer simulation in the planning phases of crop genetic improvement, the basics of model building, statistical considerations, and key issues to be addressed. Examples of publicly available simulation software for plant breeding scenarios are described (features, functionalities, and assumptions) and new directions for improved/expanded approaches and tools are discussed.