The goal of a plant breeding program is to develop new cultivars of a crop kind with improved yield and quality for a target region and end-use. Improved yield across locations and years means better adaptation to the climatic, soil, and management conditions in the target region. Improved or maintained quality renders and adds value to the improved yield. Both yield and quality must be considered simultaneously, which constitutes the greatest challenge to successful cultivar development. Cultivar development consists of two stages: the development of a promising breeding population and the selection of the best genotypes out of it. A complete breeder's equation was presented to cover both stages, which consists of three key parameters for a trait of interest: the population mean (μ), the population variability (σ_G), and the achieved heritability (h² or H), under the multi-location, multi-year framework. Population development is to maximize μσ_G and progeny selection is to improve H. Approaches to improve H include identifying and utilizing repeatable genotype by environment interaction (GE) through mega-environment analysis, accommodating unrepeatable GE through adequate testing, and reducing experimental error via replication and spatial analysis. Related concepts and procedures were critically reviewed, including GGE (genotypic main effect plus genotype by environment interaction) biplot analysis, GGE + GGL (genotypic main effect plus genotype by location interaction) biplot analysis, LG (location-grouping) biplot analysis, stability analysis, spatial analysis, adequate testing, and optimum replication. Selection on multiple traits includes independent culling and index selection, for the latter GYT (genotype by yield^*trait) biplot analysis was recommended. Genomic selection may provide an alternative and potentially more effective approach in all these aspects. Efforts were made to organize and comment on these concepts and procedures in a systematic manner.

植物育种计划的目标是为目标区域和最终用途开发具有更高产量和质量的新作物品种。不同地点和年份的产量提高意味着更好地适应目标地区的气候、土壤和管理条件。改进或保持的质量呈现并增加了改进的产量的价值。产量和质量必须同时考虑，这是成功培育品种的最大挑战。品种开发包括两个阶段：有希望的育种种群的开发和从中选择最佳基因型。提出了一个完整的育种方程来涵盖这两个阶段，其中包含感兴趣性状的三个关键参数：种群均值 (μ)、种群变异性 (σ_G)，以及达到的遗传力 (H²或H)，在多地点、多年框架下。人口发展是最大化μσ_G 和后代选择是为了提高 H. 改进方法H包括通过大环境分析通过环境相互作用（GE）识别和利用可重复的基因型，通过充分的测试适应不可重复的基因型，以及通过复制和空间分析减少实验误差。对相关概念和程序进行了严格审查，包括 GGE（基因型主效应加环境相互作用的基因型）双标分析、GGE + GGL（基因型主效应加位置相互作用的基因型）双标分析、LG（位置分组）双标分析、稳定性分析、空间分析、充分的测试和最佳复制。多性状选择包括独立剔除和指数选择，对于后者 GYT（基因型按产量^*trait) 双标分析被推荐。在所有这些方面，基因组选择可能会提供另一种可能更有效的方法。努力以系统的方式组织和评论这些概念和程序。