Simulation approach and its applications in plant breeding

Chinese. 传统植物育种很大程度上依赖于表型选择和育种家的经验，分子生物学积累的大量遗传数据使得在基因水平上进行目标性状的选择成为可能，但是由于缺乏必要的工具，大量的遗传信息尚未在育种中得以有效利用。模拟方法可以利用各类遗传信息，在育种家进行田间试验之前，对杂交组合的表现、后代选择效果以及整个育种过程进行模拟，提出最佳的亲本选配、杂交和后代选择策略，从而提高常规育种的预见性和效率。本文介绍育种模拟的一些基本原理，包括遗传模型的构建、杂交类型和选择方法的定义等，概述育种模拟工具QuLine的基本功能及其在育种方法的比较、利用已知基因信息的亲本选配和设计育种等方面的应用。模拟方法通过定义复杂的遗传模型和育种方法实现对育种过程的模拟，在更真实的情形下比较不同育种方法的优劣、预测不同亲本杂交后代的表现，从而为育种家有效利用大量的分子信息和遗传数据提供了手段。

English. Conventional plant breeding largely depends on phenotypic selection and breeding experience, therefore breeding efficiency is low and predictions are inaccurate. Along with the fast development in molecular biology and biotechnology, a large amount of biological data is available for genetic studies of important breeding traits in plants, which in turn allows conducting genotypic selection in the breeding process. However, gene information has not been effectively used in crop improvement due to the lack of appropriate tools. The simulation approach can use vast and diverse genetic information, predict cross performance, and compare different selection methods. Hence, the best performing crosses and effective breeding strategies can be identified. QuLine is a computer tool capable of defining a range from simple to complex genetic models and simulating breeding processes for developing final advanced lines. Based on the results from simulation experiments, breeders can optimize their breeding methodology and greatly improve the breeding efficiency. In this paper, we first introduce the underlying principles of simulation modeling in crop enhancement, and then summarize several applications of QuLine in comparing different selection strategies, precision parental selection using known gene information, and the design approach in breeding. Breeding simulation allows the definition of complicated genetic models consisting of multiple alleles, pleiotropy, epistasis and gene by environment interaction, and provides a useful tool to efficiently use the wide spectrum of genetic data and information available to breeders.