Litchi (Litchi chinensis Sonn.), an important fruit tree in tropical and subtropical regions, possesses substantial economic value. The branch- and leaf-related traits of litchi have a significant impact on litchi yield and quality. However, due to limitations such as the density of the genetic linkage map, there have been few studies on mapping QTLs of branch- and leaf-related traits. In this study, a high-density genetic map was constructed by next-generation sequencing (NGS) using an F1 population of 264 progenies, derived from the cross between the cultivars ‘Sanyuehong’ and ‘Ziniangxi’. A total of 2574 high-quality BINs (binomial intervals) were obtained, and a genetic linkage map was constructed with a total length of 1753.3 cM and an average marker distance of 0.68 cM. With the genetic map and the phenotyping of single leaf length (SLL), single leaf width (SLW), leaf shape index (LSI), weight of specific leaf (WSL), petiole length (PL) and compound leaf length (CLL) measured in three seasons, 11, 9, 9, 10, 9 and 12 QTLs were detected for SLL, SLW, WSL, LSI, PL and CLL traits, respectively. Among these QTLs, five QTLs were consistently detected in two seasons and 12 pleiotropic QTLs were identified for at least two traits. These findings will provide new insights for the gene cloning for branch- and leaf-related traits as well as marker-assisted selection (MAS).

中文翻译：

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利用荔枝 (Litchi chinensis Sonn.) 高密度 SNP 遗传图谱对枝叶相关性状进行 QTL 定位


荔枝（Litchi chinensis Sonn.）是热带、亚热带地区的重要果树，具有巨大的经济价值。荔枝枝叶相关性状对荔枝产量和品质影响显着。但由于遗传连锁图谱密度等限制，目前针对枝叶相关性状QTL定位的研究还很少。在本研究中，利用源自“三月红”和“紫娘溪”品种杂交的 F1 群体 264 个后代，通过新一代测序 (NGS) 构建了高密度遗传图谱。共获得2574个高质量BIN（二项式区间），构建遗传连锁图谱，总长1753.3 cM，平均标记距离0.68 cM。测量遗传图谱和单叶长度（SLL）、单叶宽度（SLW）、叶形指数（LSI）、特定叶重量（WSL）、叶柄长度（PL）和复叶长度（CLL）的表型三个季节中，分别检测到SLL、SLW、WSL、LSI、PL和CLL性状的11、9、9、10、9和12个QTL。在这些 QTL 中，在两个季节中一致检测到 5 个 QTL，并且针对至少两个性状鉴定了 12 个多效性 QTL。这些发现将为枝叶相关性状的基因克隆以及标记辅助选择（MAS）提供新的见解。