Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, CN-266000, China.
Ruijin Branch, Jiangxi Ganzhou Tobacco Company of China Tobacco Corporation, Ganzhou, CN-341000, China.
BMC Plant Biol. 2024 Jun 20;24(1):583. doi: 10.1186/s12870-024-05261-8.
Leaf morphology plays a crucial role in photosynthetic efficiency and yield potential in crops. Cigar tobacco plants, which are derived from common tobacco (Nicotiana tabacum L.), possess special leaf characteristics including thin and delicate leaves with few visible veins, making it a good system for studying the genetic basis of leaf morphological characters.
In this study, GWAS and QTL mapping were simultaneously performed using a natural population containing 185 accessions collected worldwide and an F population consisting of 240 individuals, respectively. A total of 26 QTLs related to leaf morphological traits were mapped in the F population at three different developmental stages, and some QTL intervals were repeatedly detected for different traits and at different developmental stages. Among the 206 significant SNPs identified in the natural population using GWAS, several associated with the leaf thickness phenotype were co-mapped via QTL mapping. By analyzing linkage disequilibrium and transcriptome data from different tissues combined with gene functional annotations, 7 candidate genes from the co-mapped region were identified as the potential causative genes associated with leaf thickness.
These results presented a valuable cigar tobacco resource showing the genetic diversity regarding its leaf morphological traits at different developmental stages. It also provides valuable information for novel genes and molecular markers that will be useful for further functional verification and for molecular breeding of leaf morphological traits in crops in the future.
叶片形态在作物的光合作用效率和产量潜力方面起着至关重要的作用。雪茄烟植物源自普通烟草（Nicotiana tabacum L.），具有特殊的叶片特征，包括叶片薄而细腻，叶脉不明显，这使其成为研究叶片形态特征遗传基础的良好系统。
本研究分别利用包含全球 185 个品系的自然群体和由 240 个个体组成的 F1 群体，同时进行了 GWAS 和 QTL 作图。在 F1 群体的三个不同发育阶段，共定位到与叶片形态性状相关的 26 个 QTL，一些 QTL 区间在不同性状和不同发育阶段被重复检测到。在利用 GWAS 在自然群体中鉴定到的 206 个显著 SNP 中，通过 QTL 作图，有几个与叶片厚度表型相关的 SNP 被共定位。通过分析不同组织的连锁不平衡和转录组数据，并结合基因功能注释，从共定位区域鉴定到 7 个候选基因，它们可能是与叶片厚度相关的潜在候选基因。
这些结果提供了一个有价值的雪茄烟草资源，展示了不同发育阶段叶片形态性状的遗传多样性。这也为未来作物叶片形态性状的新基因和分子标记的进一步功能验证和分子育种提供了有价值的信息。
