Modifying plant architecture is often necessary for yield improvement and climate adaptation, but we lack understanding of the genotype‐phenotype map for plant morphology in sorghum. Here, we use a nested association mapping (NAM) population that captures global allelic diversity of sorghum to characterize the genetics of leaf erectness, leaf width (at two stages), and stem diameter. Recombinant inbred lines (n = 2200) were phenotyped in multiple environments (35,200 observations) and joint linkage mapping was performed with ∼93,000 markers. Fifty‐four QTL of small to large effect were identified for trait BLUPs (9–16 per trait) each explaining 0.4–4% of variation across the NAM population. While some of these QTL colocalize with sorghum homologs of grass genes (e.g., those involved in transcriptional regulation of hormone synthesis [rice SPINDLY] and transcriptional regulation of development [rice Ideal plant architecture1]), most QTL did not colocalize with an a priori candidate gene (92%). Genomic prediction accuracy was generally high in five‐fold cross‐validation (0.65–0.83), and varied from low to high in leave‐one‐family‐out cross‐validation (0.04–0.61). The findings provide a foundation to identify the molecular basis of architecture variation in sorghum and establish genomic‐enabled breeding for improved plant architecture.

中文翻译：

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全基因组映射和高粱嵌套关联映射种群中的植物结构预测

改变植物结构对于提高产量和适应气候变化通常是必需的，但是我们对高粱植物形态的基因型-表型图缺乏了解。在这里，我们使用一个嵌套的关联映射（NAM）种群来捕获高粱的全球等位基因多样性，以表征叶片直立，叶片宽度（在两个阶段）和茎直径的遗传。重组自交系（Ñ = 2200）在多种环境中进行表型分析（观察到35,200），并使用约93,000个标记进行了联合连锁作图。对于性状BLUP（每个性状9-16），确定了54个从小到大的QTL，每个QTL解释了整个NAM群体的0.4-4％的变异。尽管其中一些QTL与草基因的高粱同源物共定位（例如，那些参与激素合成的转录调控[大米SPINDLY ]和发育的转录调控[大米理想的植物结构1]]），大多数QTL并未与先验候选基因共定位（92％）。基因组预测准确性通常在五重交叉验证中较高（0.65-0.83），而在离开一亲子交叉验证中从低到高变化（0.04-0.61）。这些发现为确定高粱结构变异的分子基础和建立基因组育种以改善植物结构奠定了基础。