Understanding the genetic architecture of leaf morphological and physiological traits will help plant breeders develop high biomass poplar genotypes. Quantitative trait locus (QTL) studies combining next-generation sequencing techniques can advance our understanding of the genetic basis of complex traits. In this study, we measured 13 leaf morphological and physiological traits and identified quantitative trait loci (QTLs) in a Populus deltoides ‘Danhong’ × P. simonii ‘Tongliao1’ F₁ population (500 progenies) using a high-density genetic map constructed by whole genome re-sequencing. This linkage map consisted of 5796 single nucleotide polymorphism (SNP) markers assigned to 19 linkage groups (LGs), spanning 2683.80 centimorgans (cM) of genetic length, with an average marker density of 0.46 cM. We identified 109 QTLs on 18 LGs for leaf morphological traits and 55 QTLs on 14 LGs for leaf physiological traits. One-hundred eight putative candidate genes were identified within the candidate genomic region. Co-expression network and gene ontology enrichment analyses suggested that these candidate genes were involved in the photosynthetic process. The differential expression patterns of the CYCLIN (Potri.015G112200) and RED CHLOROPHYLL REDUCTASE (Potri.007G043600) genes between two parents indicated their potential roles in leaf morphological and physiological traits. These findings decipher the genetic architecture of leaf morphological and physiological traits in the P. deltoides ‘Danhong’ × P. simonii ‘Tongliao1’ pedigree and provide candidate genes for future poplar genetic improvement.

了解叶片形态和生理特性的遗传结构将有助于植物育种者发展高生物量的杨树基因型。结合下一代测序技术的定量性状基因座（QTL）研究可以增进我们对复杂性状遗传基础的理解。在这项研究中，我们测量了13个叶片的形态和生理特征，并确定了三角果“单红”×拟南芥“ Tongliao1” F _1中的数量性状基因座（QTL）。使用通过全基因组重新测序构建的高密度遗传图谱分析种群（500个子代）。该连锁图由5796个单核苷酸多态性（SNP）标记组成，这些标记分配给19个连锁组（LG），遗传长度为2683.80厘摩（cM），平均标记密度为0.46 cM。我们确定了18个LG的109个QTL的叶片形态性状和14个LG的55个QTL的叶片生理性状。在候选基因组区域内鉴定了一百八十个候选基因。共表达网络和基因本体论富集分析表明这些候选基因参与了光合作用过程。所述的差异表达模式，Cyclin（Potri.015G112200）和RED叶绿素还原酶两个亲本之间的（Potri.007G043600）基因表明它们在叶片形态和生理性状中的潜在作用。这些发现破译了P. deltoides'Danhong '× P. simonii'Tongliao1 '系的叶片形态和生理特性的遗传结构，并为将来的杨树遗传改良提供了候选基因。