Key Laboratory of Tobacco Biotechnological Breeding, National Tobacco Genetic Engineering Research Center, Yunnan Academy of Tobacco Agricultural Sciences, Kunming, Yunnan 650021, China.
Institute of Bioinformatics and Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China.
Gene. 2024 Nov 30;928:148765. doi: 10.1016/j.gene.2024.148765. Epub 2024 Jul 15.
Tobacco is an economically significant industrial crop and model plant for genetic research, yet little is known about its genetic architecture. Quantitative trait loci (QTL) analysis was performed for six agronomic traits on an F_7 population of 341 genotypes, parents, and F plants using 1974 SSR markers across two environments. 31 QTLs contributing single-locus additive effects on 13 linkage groups (LGs) and 6 QTL pairs contributing epistatic effects on 6 LGs, were detected by the QTLNetwork 2.0 which was developed for the mixed-linear-model-based composite interval mapping (MCIM). Notably, 5 QTLs and 1 epistatic QTL pair were found to have pleiotropic effects on some genetically related traits. Moreover, the Broad sense heritability of the detected QTLs ranged from 1.05% to 43.33%, while genotype-by-environment interaction heritability spanned from 27.09% to 56.25%. Based on the results of QTL mapping, the potential superior lines for all or specific environments were designed and evaluated. Five major QTLs were finely dissected based on the tobacco reference genome of K326, and 31 candidate genes were predicted. This study offered new insights into the complicated genetic architecture and QTL resources for efficient breeding design for genetic improvement of agronomic traits in tobacco.
烟草是一种经济上重要的工业作物和遗传研究的模式植物，但对其遗传结构知之甚少。利用分布于 13 个连锁群（LG）的 1974 个 SSR 标记，在两个环境下，对 341 个基因型、亲本和 F1 代的 6 个农艺性状进行了 F7 群体的数量性状位点（QTL）分析。利用基于混合线性模型的复合区间作图（MCIM）开发的 QTLNetwork 2.0，检测到 13 个连锁群上的 31 个单基因加性效应 QTL 和 6 个连锁群上的 6 对上位性效应 QTL。值得注意的是，发现 5 个 QTL 和 1 个上位性 QTL 对一些遗传上相关的性状具有多效性。此外，所检测到的 QTL 的广义遗传力范围为 1.05%至 43.33%，而基因型-环境互作遗传力范围为 27.09%至 56.25%。基于 QTL 作图的结果，设计和评估了所有或特定环境的潜在优势品系。根据 K326 的烟草参考基因组，精细剖析了 5 个主要 QTL，并预测了 31 个候选基因。本研究为烟草农艺性状遗传改良的高效育种设计提供了对复杂遗传结构和 QTL 资源的新见解。
