背景+问题：Appropriate root system architecture (RSA) can improve maize yields in densely planted fields, but little is known about its genetic basis in maize. 

主要发现：Here we performed root phenotyping of 14,301 field-grown plants from an association mapping panel to study the genetic architecture of maize RSA. 

结果1-全基因组关联分析：A genome-wide association study identified 81 high-confidence RSA-associated candidate genes and revealed that 28 (24.3%) of known root-related genes were selected during maize domestication and improvement. 

结果2-现代育种对玉米根系的塑造：We found that modern maize breeding has selected for a steeply angled root system. Favourable alleles related to steep root system angle have continuously accumulated over the course of modern breeding, and our data pinpoint the root-related genes that have been selected in different breeding eras. 

结果3-新基因：We confirm that two auxin-related genes, ZmRSA3.1 and ZmRSA3.2, contribute to the regulation of root angle and depth in maize. 

结论：Our genome-wide identification of RSA-associated genes provides new strategies and genetic resources for breeding maize suitable for high-density planting.

Genes that have been reported to affect the development of maize roots.

合适的根系结构（RSA）可以提高密集型种植玉米的产量，但对其遗传基础知之甚少。本文中，作者通过对来自于一个关联群体的14301株大田种植的玉米进行了根表型分析，以研究玉米根系结构的遗传结构。全基因组关联分析确定了共81个与玉米根系结构相关的高置信候选基因，其中28个（占比24.3%）是已知的根发育相关基因，在玉米的驯化和改良过程中受到了选择。作者发现，现代玉米育种选择了一个陡峭角度的根系。在现代育种过程中，与陡峭根系角度相关的有利等位基因不断积累，本文的数据精确地指出了在不同育种时期选择的与根系相关的基因。作者揭示了两个生长素相关基因ZmRSA3.1和ZmRSA3.2作用于玉米根系角度和深度的调控。作者对玉米根系结构相关基因的全基因组鉴定，为培育适合密集型种植的玉米提供了新的策略和遗传资源。