Ear traits play a vital role in maize (Zea mays) yield. The ear angle (EA) has an obvious impact on corn yield and planting density as well as other maize ear traits. However, the genetic control of EA is still unclear. In this study, we identified quantitative trait loci (QTLs) for EA from four recombinant inbred line populations, BY815/DE3, BY815/K22, CI7/K22 and Mo17/X26-4, which were grown in three environments, and the genetic architecture of EA in maize was subsequently dissected. The results indicated that maize EA was highly heritable and was affected by both genotype and environment. Based on the genetic linkage map constructed using 56,110 bins as markers, nine effective QTLs for maize EA were detected locating on chromosomes 2, 3, 4, 6 and 7. These QTLs accounted for different EA variations ranging from 5.5% (qCIKEA6) to 7.6% (qBYKEA3). Moreover, 14 candidate genes were identified from the reduced QTLs using a bin-map method, which mainly encoded enzymes in signal transduction, transcriptional regulation and metabolism. Conclusively, our results can benefit further study of the genetic basis of EA and improve the maize EA quality through molecular breeding.

中文翻译：

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高密度单核苷酸多态性标记揭示四个重组自交系群体玉米穗角的遗传基础

穗性状在玉米（Zea mays）产量中起着至关重要的作用。穗角（EA）对玉米产量和种植密度以及其他玉米穗性状有明显影响。然而，EA的遗传控制仍不清楚。在这项研究中，我们从四个重组自交系群体 BY815/DE3、BY815/K22、CI7/K22 和 Mo17/X26-4 中鉴定了 EA 的数量性状位点 (QTL)，它们在三种环境中生长，以及遗传结构随后对玉米中的 EA 进行了解剖。结果表明，玉米EA具有高度遗传性，受基因型和环境影响。基于以56,110个bin为标记构建的遗传连锁图谱，在2、3、4、6和7号染色体上检测到9个玉米EA的有效QTL。这些QTL解释了从5.5%（qCIKEA6）到7.6的不同EA变异% (qBYKEA3)。此外，使用bin-map方法从减少的QTL中鉴定出14个候选基因，其主要编码信号转导、转录调控和代谢中的酶。总之，我们的研究结果有助于进一步研究EA的遗传基础，并通过分子育种提高玉米EA的品质。