Major advances in crop yields are needed in the coming decades. However, plant breeding is currently limited by incremental improvements in quantitative traits that often rely on laborious selection of rare naturally occurring mutations in gene-regulatory regions. Here, we demonstrate that CRISPR/Cas9 genome editing of promoters generates diverse cis-regulatory alleles that provide beneficial quantitative variation for breeding. We devised a simple genetic scheme, which exploits trans-generational heritability of Cas9 activity in heterozygous loss-of-function mutant backgrounds, to rapidly evaluate the phenotypic impact of numerous promoter variants for genes regulating three major productivity traits in tomato: fruit size, inflorescence branching, and plant architecture. Our approach allows immediate selection and fixation of novel alleles in transgene-free plants and fine manipulation of yield components. Beyond a platform to enhance variation for diverse agricultural traits, our findings provide a foundation for dissecting complex relationships between gene-regulatory changes and control of quantitative traits.

中文翻译：

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通过基因组编辑改善作物产量的工程定量性状变异。

在未来几十年中，需要在作物单产上取得重大进展。但是，植物育种目前受到定量性状的不断改善的限制，这些性状常常依赖于在基因调控区域中罕见地自然发生的突变的繁重选择。在这里，我们证明了启动子的CRISPR / Cas9基因组编辑产生了多种顺式调控等位基因，为育种提供了有益的定量变异。我们设计了一种简单的遗传方案，该方案利用杂合功能缺失突变体背景下Cas9活性的跨代遗传力，来快速评估众多启动子变体对调节番茄三个主要生产力性状的基因的表型影响：果实大小，花序分支和工厂架构。我们的方法允许在无转基因植物中立即选择和固定新等位基因，并对产量成分进行精细操作。除了为各种农业特性增强变异的平台之外，我们的发现还为剖析基因调控变化与数量性状控制之间的复杂关系提供了基础。