Tong Zhijun, Xu Manling, Zhang Qixin, Lin Feng, Fang Dunhuang, Chen Xuejun, Zhu Tianneng, Liu Yingchao, Xu Haiming, Xiao Bingguang
Key Laboratory of Tobacco Biotechnological Breeding, National Tobacco Genetic Engineering Research Center, Yunnan Academy of Tobacco Agricultural Sciences, Kunming, Yunnan, China.
Institute of Bioinformatics and Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China.
Front Plant Sci. 2023 Feb 15;14:1126529. doi: 10.3389/fpls.2023.1126529. eCollection 2023.
Tobacco ( L.) is an economic crop and a model organism for studies on plant biology and genetics. A population of 271 recombinant inbred lines (RIL) derived from K326 and Y3, two elite flue-cured tobacco parents, has been constructed to investigate the genetic basis of agronomic traits in tobacco. Six agronomic traits including natural plant height (nPH), natural leaf number (nLN), stem girth (SG), inter-node length (IL), length of the largest leaf (LL) and width of the largest leaf (LW) were measured in seven environments, spanning the period between 2018 and 2021. We firstly developed an integrated SNP-indel-SSR linkage map with 43,301 SNPs, 2,086 indels and 937 SSRs, which contained 7,107 bin markers mapped on 24 LGs and covered 3334.88 cM with an average genetic distance of 0.469cM. Based on this high-density genetic map, a total of 70 novel QTLs were detected for six agronomic traits by a full QTL model using the software , of which 32 QTLs showed significant additive effects, 18 QTLs showed significant additive-by-environment interaction effects, 17 pairs showed significant additive-by-additive epistatic effects and 13 pairs showed significant epistasis-by-environment interaction effects. In addition to additive effect as a major contributor to genetic variation, both epistasis effects and genotype-by-environment interaction effects played an important role in explaining phenotypic variation for each trait. In particular, was detected with considerably large main effect and high heritability ( =34.80%). Finally, four genes including , , , were predicted as pleiotropic candidate genes for five traits.
烟草（Nicotiana tabacum L.）是一种经济作物，也是植物生物学和遗传学研究的模式生物。为了研究烟草农艺性状的遗传基础，构建了一个由271个重组自交系（RIL）组成的群体，这些重组自交系来自两个优良烤烟亲本K326和Y3。在2018年至2021年期间的七个环境中，测量了六个农艺性状，包括自然株高（nPH）、自然叶数（nLN）、茎围（SG）、节间长度（IL）、最大叶长度（LL）和最大叶宽度（LW）。我们首先构建了一个整合的SNP-插入缺失-SSR连锁图谱，其中包含43301个SNP、2086个插入缺失和937个SSR，该图谱包含7107个bin标记，定位在24个连锁群（LG）上，覆盖3334.88 cM，平均遗传距离为0.469 cM。基于这个高密度遗传图谱，使用该软件通过全QTL模型检测到六个农艺性状的总共70个新QTL，其中32个QTL表现出显著的加性效应，18个QTL表现出显著的加性×环境互作效应，17对表现出显著的加性×加性上位性效应，13对表现出显著的上位性×环境互作效应。除了加性效应是遗传变异的主要贡献者外，上位性效应和基因型×环境互作效应在解释每个性状的表型变异中也起着重要作用。特别是，检测到具有相当大的主效应和高遗传力（h² = 34.80%）。最后，预测了四个基因，包括Ntab02g027780、Ntab04g003370、Ntab06g053620、Ntab07g053330，作为五个性状的多效性候选基因。
