To investigate how Yunnan's distinctive geographical and climatic conditions shape the unique metabolic profile of its cigar tobacco leaves (CTLs), and to establish a reliable method for origin traceability using machine learning, a non-targeted metabolomics analysis was conducted on 71 CTL samples collected from the Dominican Republic, Indonesia, and Yunnan, including Lincang, Pu’er, and Yuxi within Yunnan. A total of 778 highly reliable metabolites were identified. Influenced by Yunnan's high altitude, large diurnal temperature variation, intense ultraviolet radiation, and relative dryness, its CTLs exhibited characteristic metabolic profiles, with significant enrichment in pathways such as flavone and flavonol biosynthesis and betalain biosynthesis. Elevated levels of polyphenols, indoles, jasmonates, carotenoids, and other compounds were linked to Yunnan CTLs' distinct woody, roasted, and astringent flavor profile. Twelve key biomarkers were selected using Multivariate methods with unbiased variable selection in R (MUVR). Machine learning algorithms—including LDA, LR, GMM, KNN, and SVM—were applied to these biomarkers, achieving highly accurate origin discrimination across national (Yunnan vs. Dominican Republic/Indonesia) and regional (Lincang, Pu’er, Yuxi) scales. Validation results showed a median false classification rate of 0.1 over 100 iterations and an AUC close to 1, confirming the model's high accuracy and robustness for CTLs origin traceability.

Nicotiana tabacum is an allotetraploid hybrid and a widely used model organism in plant genetics. Despite its agricultural and biological significance, large-scale genomic studies and comprehensive analysis of population differentiation in tobacco remain limited. Here, we perform whole-genome resequencing of 2032 diverse tobacco accessions, identifying 59 million single-nucleotide polymorphisms and 8.3 million small insertions and deletions. These variants contribute to substantial genetic diversity both within and between populations. Population genetic structure analysis reveals two major genetic subpopulations, with the differentiation primarily driven by breeding practices. Notably, the genetic differentiation between varieties is greater than that observed between tobacco types. Shared divergent regions across six types are enriched in defense, epidermal development, and lipid metabolism pathways, reflecting selection for stress adaptation and plant growth. We further identify 302 accessions exhibiting strong signatures of selection in immune-related genes, highlighting their potential as parental lines in resistance breeding programs. Selective sweeps in major cultivars overlap with 19 previously identified quantitative trait loci, primarily associated with agronomic traits such as leaf morphology, disease resistance, and chemical traits. This study provides a high-resolution genomic resource for in-depth tobacco genomics research and offers valuable insights into precision breeding.

Tobacco is one of the most important model plants. Plant height is one of the most important agronomic traits in tobacco. To better understand the population genetic structure and the genetic basis of plant height in tobacco, 437 tobacco germplasms were whole genome re-sequencing in this study. A total of 2,263,775 high-quality single nucleotide polymorphisms were identified. The analysis of the population genetic structure showed that tobacco germplasm could be divided into 8 clusters. In addition, gene flow was found between flue-cured tobacco and ustic tobacco, as well as between oriental tobacco and air-cured tobacco. Three genes associated with plant height were identified as candidate genes by genome-wide association study. This study provides valuable genetic resources for population structure analysis and elucidation of the genetic basis of various traits. It helps to improve the efficiency of molecular breeding.

The common tobacco (Nicotiana tabacum) is an important model plant applied in basic life science. In this study, we re-sequenced 391 diverse tobacco germplasms with mean genome coverage of 11.6 × . A total of 17.9 M single nucleotide polymorphisms (SNPs) were identified which revealed the average SNP frequency 6 SNP/Kb and diversity (π) about 0.4 × 10–3. Compared the genetic diversity and divergence between tobaccos from China (TChina) and from USA (TUSA), significant differences were found in Nt01 and Nt05, and selective sweeps revealed the regional selections for genes enriched in pathways of photosynthesis and sesquiterpenoids and triterpenoids biosynthesis. Genomic transmission and conservation patterns along chromosomes were also evaluated for 10 tobacco cultivars which highlighted genome blocks under selection in the past. Based on the millions of SNPs, a high density tobacco SNP array Nt660YN was designed and validated, which was composed of 588,553 PolyHighResolution SNPs with an average 3.5 SNPs per gene. The millions of SNPs and Nt660YN SNP array will facilitate genetic researches in Nicotiana as well as all Solanaceae crops.

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Potassium ion (K+) is one of the most essential nutrients for the growth and development of tobacco (Nicotiana tabacum L.), however, the molecular regulation of K+ concentration in tobacco remains unclear. In this study, a two-pore K (TPK) channel gene NtTPKa was cloned from tobacco, and NtTPKa protein contains the unique K+ selection motif GYGD and its transmembrane region primarily locates in the tonoplast membrane. The expression of NtTPKa gene was significantly increased under low-potassium stress conditions. The concentrations of K+ in tobacco were significantly increased in the NtTPKa RNA interference lines and CRISPR/Cas9 knockout mutants. In addition, the transport of K+ by NtTPKa was validated using patch clamp technique, and the results showed that NtTPKa channel protein exclusively transported K+ in a concentration-dependent manner. Together, our results strongly suggested that NtTPKa is a key gene in maintaining K+ homeostasis in tobacco, and it could provide a new genetic resource for increasing the concentration of K+ in tobacco.

赤星病是烟草上的重要叶部病害,每年给烟草生产造成巨大损失,培育抗赤星病品种是防治烟草赤星病为害的根本措施,而对赤星病抗性关联遗传位点的发掘、鉴定和利用是培育抗赤星病烟草品种的关键基础.本研究利用抗赤星病的烟草材料'Beinhart 1000-1'和加工品质好但不抗赤星病的烟草品种'K326',通过种间杂交和F1代自交分离,创建了'Beinhart 1000-1'和'K326'的F2代杂交分离群体.随后,通过赤星病抗病性鉴定,本研究在F2代分离群体中选择了 19株抗赤星病材料和19株感赤星病材料,分别进行了基因组DNA提取,并通过BSA法进行了基因组重测序.在重测序数据分析基础上结合表型鉴定结果,本研究鉴定出差异SNP位点约170万个,进行烟草赤星病抗性关联SNP位点分析,找到赤星病抗性相关基因10个,促进了烟草抗赤星病分子育种的发展.

为了解烤烟种质资源叶片收缩性状和经济性状的遗传多样性,对158份烤烟资源的叶片收缩性状(中部8～10叶位)和经济性状进行遗传多样性分析、相关性分析、因子分析和聚类分析.结果表明,参试资源16个性状的变异系数为7.41%～73.36%,平均22.01%;遗传多样性指数为1.912 3～2.090 9,平均2.022 4.烤烟叶片收缩率表现为叶面积(33.21%)>叶宽(24.82%)>叶长(11.21%).相关性分析表明,叶长、叶宽、叶面积的收缩值和收缩率与产量相关性不显著,与产值和均价呈极显著负相关;叶宽、叶面积的收缩值和收缩率与上等烟比例呈显著或极显著负相关.因子分析表明,叶片收缩因子与烟叶等级质量及产值因子具有负相关关系.158份参试资源在相似距离35.0处可聚为4个类群,类群间性状差异极显著,其中Ⅲ类群资源烘烤后叶片较大,收缩率小,经济性状好,聚在Ⅲ类群的6份资源'云烟97''长脖黄''云烟116''峨山烤烟''红花云烟85''GL939',其叶片收缩率中等至小,烟叶等级质量和种植效益突出.综上所述,158份烤烟资源在叶片收缩性状及经济性状上具有丰富的遗传多样性,叶片收缩过大对烟叶等级质量及产值有不利影响;6份优异资源可用于烟叶生产或优质品种选育.

[背景和目的]RBRR1是通过远缘杂交与回交导入栽培烟草的一个单显性广谱型根黑腐病抗病位点,为了开发基于该位点的简单高效稳定且成本低的紧密连锁分子标记.[方法]在已有酶切扩增多态性序列(Cleaved amplified polymorphism sequences,CAPS)标记相关序列基础上,利用云晒1号基因组与抗、感根黑腐病材料重测序信息,基于其序列插入/缺失(Insertion/Deletion,InDel)多态性设计抗病相关分子标记,并开展遗传效应和遗传变异分析.[结果]筛选到4对具有良好多态性的引物,在目标单株的分子标记辅助选择中具备便捷、高效且呈共显性的特点.遗传效应分析表明,通过分子标记辅助选择导入RBRR1位点能够极显著提高栽培烟草根黑腐病抗性.遗传变异分析结果显示,在烟草核心种质资源中仅有白肋烟TN90和SoTa2携带有RBRR1抗病基因,并发现4对引物在普通烟草自然群体中呈现2种基因型.[结论]RBRR1抗病位点在我国尚未进行广泛利用,具有较高的利用价值;而开发的4个InDel标记可用于该抗性位点的分子标记辅助选择育种和后续抗病基因的精细定位与克隆.

Backcrossing is a powerful tool for plant breeding. The improved marker-assisted backcrossing intends to transfer targeted genes or quantitative trait loci (QTLs) of interest from a donor parent into a recurrent parent. In this study, a tobacco BC4F3 population was generated using Y3 and K326 as hybrid parents and YF1-1 as F1 parents. High-throughput sequencing data of 381 pedigree populations were used to construct high-density genetic maps containing 24 142 high-quality single nucleotide polymorphism (SNP) markers with an average genetic distance of 0.59 cM. A genome module analysis was then performed for all the offspring. A total of forty-three candidate QTLs for six agronomics traits were identified. This study provides original biomarkers for tobacco breeding and offers clues for prospective backcrossing applications in other plants.

The biosynthesis and transport of nicotine has been shown to be coordinately upregulated by jasmonate (JA). MYC2, a member of basic helix-loop-helix (bHLH) transcription factor family, is well-documented as the core player in the JA signalling pathway to regulate diverse plant development processes. Four MYC2 genes were found in the tobacco genome, NtMYC2a/2b and 1a/1b. In this study, we tested whether one of them, NtMYC2a, acts as a 'master switch' in the regulation of nicotine biosynthesis and transport in tobacco. We generated NtMYC2a knockout tobacco plants using the CRISPR-Cas9 technique and analysed the effect of NtMYC2a knockout on expression of the nicotine biosynthesis genes (NtAO, NtQS, NtPMT1a, NtQPT2, NtODC2, NtMPO1, NtA622 and NtBBLa) and transport genes (NtMATE2 and NtJAT1), as well as leaf accumulation of nicotine in the NtMYC2a knockout plants. We found that all the nicotine biosynthesis and transport genes tested in this study were significantly downregulated (>50% reduction compared with wild-type control) in the NtMYC2a knockout plants. Moreover, the leaf nicotine content in knockout plants was dramatically reduced by ca 80% compared with the wild-type control. These results clearly show that NtMYC2a acts as a 'master switch' to coordinate JA-induced nicotine accumulation in tobacco and suggests that NtMYC2a might play an important role in tobacco nicotine-mediated defence against herbivory.

为明确烤烟种质资源物理特性的遗传多样性,有效利用种质资源,选取了269份烤烟种质资源C3F烟叶6个物理特性指标进行了遗传多样性和聚类分析.结果表明:①参试种质资源的物理特性指标变异系数在6.73％～20.25％范围内,遗传多样性指数为1.934～2.050,平均2.014.②国内种质资源物理特性平均遗传多样性指数(1.979)略高于美国资源(1.956)和其他资源(1.932),国内地方种质资源物理特性平均遗传多样性指数(2.628)高于杂交选育资源(1.922).③参试种质资源在相似距离0.982处可聚为4个类群,类群间指标存在极显著差异,Ⅰ类群、Ⅱ类群资源物理特性分值高于Ⅲ类群、Ⅳ类群,丰字6号、黄苗榆、B22、革新6号、牡单81-56、黑玉米棒子、凤城黄金等7份资源的物理特性指标均在最适宜或适宜范围,物理特性指标分值较高.因此参试烤烟种质资源物理特性的遗传多样性较丰富,国内地方种质资源物理特性的遗传多样性比杂交选育的种质资源丰富,物理特性优异的7份种质资源可供品种选育或品种物理特性改良时加以利用.

烟草普通花叶病(TMV)是烟区的主要病害之一,生产上所用抗源都来自烟属的心叶烟(Nicotiana glutinosa),其携带N基因对TMV免疫,但因连锁累赘导致烟叶品质差,难以在生产上大面积使用.因此,从烟属植物中挖掘新的TMV抗源尤为必要.本研究以烤烟品种红花大金元与野生种圆锥烟草(N.paniculata,PI 555550)为亲本,开展远缘杂交,获得了种间杂种.杂交种SSR、GISH及抗病性鉴定结果表明,杂交种含双亲特征条带,接种TMV后,叶片有枯斑反应.N基因特异引物在圆锥烟草及杂交种中未能扩增,而根据N基因同源基因Np片段设计的特异引物扩增到500 bp的片段,携带N基因的RBST及心叶烟草(N.glutinosa PI 555507)中未扩增到此特异片段,在杂交种扩增到此特异片段.该研究为获得新的TMV抗源奠定了材料基础.

Background: Short Tandem repeats (STRs) existed as popular elements in both eukaryotic and prokaryotic genomes. Results: In this study, we analyzed the characteristics, distributions, and motif features of STRs within whole-genomes of 140 plant species. The results showed that STR density was negatively correlated with the genome size. Hexanucleotide repeat was the most abundant type of STRs. The distribution of algae shows a preference different from that of other plants. By analyzing GC contents of STRs and genome, it was concluded that STR motif was influenced by GC contents. Analysis of the long STRs in genome (length >= 1000 bp) found that dicots have the more long STRs. For STR types, di- and tri-nucleotide accounted for the highest proportion. Analyzing and designing long STRs in CDS (length >= 500 bp) was to verify the role of long STRs in Gossypium hirsutum TM-1 and Solanum tuberosum. By comparing the long STRs found in Fragaria x ananassa with other species, some evolutionary characteristics of the long STRs were obtained. Conclusions: We got the characteristics, distribution, and motif features of STRs in the whole genome of 140 plants and obtained some evolutionary characteristics of long STRs. The study provides useful insights into STR preference, characteristics, and distribution in plants. (C) 2020 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V.

Nicotiana alata is an ornamental horticultural plant with a variety of flower colors and a long flowering period. The genes in four different colored N. alata (white, purple, red, and lemon green) were analyzed to explain the differences in flower color using transcriptomes. A total of 32 differential expression genes in the chlorophyll biosynthesis pathway and 41 in the anthocyanin biosynthesis pathway were identified. The enrichment analysis showed that the chlorophyll biosynthesis pathway and anthocyanin biosynthesis pathway play critical roles in the color differences of N. alata. The HEMA of the chlorophyll biosynthesis pathway was up-regulated in lemon green flowers. Compared with white flowers, in the red and purple flowers, F3H, F3′5′H and DFR were significantly up-regulated, while FLS was significantly down-regulated. Seventeen differential expression genes homologous to transcription factor coding genes were obtained, and the homologues of HY5, MYB12, AN1 and AN4 were also involved in flower color differences. The discovery of these candidate genes related to flower color differences is significant for further research on the flower colors formation mechanism and color improvements of N. alata.

本研究以烤烟品种'云烟97'和'变异云烟97'为亲本,分别构建P1、P2、F1和F24个世代遗传群体,利用植物数量性状主基因+多基因混合遗传模型方法对烟草的株高、节距、叶数和茎围进行遗传及相关分析.结果 表明,株高分别与节距、叶数间呈极显著正相关,与茎围间呈显著正相关;而节距与叶数间则呈现极显著负相关.株高、节距和叶数3个性状具有相同的最优遗传模型,即2对加性-显性-上位性主基因+加性-显性多基因混合遗传模型(MX2-ADI-AD),其主基因遗传率分别为95.2258％、94.2854％和99.1771％,多基因遗传率分别为4.7742％、5.5684％和0.8229％;茎围性状符合2对加性-显性主基因+加性-显性多基因混合最优遗传模型(MX2-AD-AD),其主基因和多基因遗传率分别为90.3146％和9.6854％.上述性状均受主基因+多基因混合遗传模型控制,主基因遗传率均高达90％以上且远大于多基因遗传率,受环境影响可以忽略.因此,在烟草高产育种过程中针对上述农艺性状的定向选择宜在早期世代进行.

云烟119是以云烟87为母本、77089为父本,采用杂交育种方法选育而成的烤烟新品种.该品种田间生长整齐一致,生长势较强,株式塔型,叶形长椭圆,平均打顶株高127.4 cm,有效叶数22片左右,大田生育期平均为124.2 d,中抗黑胫病、根结线虫病;主要经济性状略优于对照K 326,各指标与对照的差异均不显著;初烤烟叶外观质量略优于对照K 326,物理特性与对照相当;各化学成分含量在适宜范围之内,协调性较好;感官质量接近于对照K 326.该品种是一个较能兼顾产量、质量和抗病性的烤烟新品种,适宜我国南方主产烟区种植.

为创制双抗黑胫病(0号生理小种)和普通花叶病(TMV)的烟草种质,采用母本来源单倍体技术将Coker371和Coker176杂交后代F1与烟属野生种非洲烟草(N.africana)杂交,经形态观察,结合流式细胞仪倍性鉴别,获得了母本来源的单倍体苗,并对分子标记辅助选择获得的目标单倍体进行叶脉培养加倍,创制了双抗黑胫病及TMV烤烟新种质RBST(Resistant to black shank and TMV).苗期人工接种抗病鉴定、分子标记辅助检测和田间农艺性状鉴定表明,RBST的抗病性和农艺性状稳定,可用作烟草品种抗性定向改良的抗源材料.

Whether quality can be improved and style characteristics of different types of tobaccos can be changed after being cured using different methods has not been clear yet. It is necessary to explore the influences of different curing methods on chemical compositions of different types of tobaccos. For this purpose, by taking flue-cured tobacco K326, burley tobacco Yunbai 3 and oriental tobacco Basma 14 as materials, the effects of air-curing, suncuring and flue-curing methods on chemical compositions of these three types of tobaccos were investigated by taking the freeze-dried tobacco as the control group based on the equilibrium method of matter loss. The results show that compared with freeze-dried tobacco, (1) The air-cured, flue-cured and sun-cured were displayed in a descending order in terms of the dry matter loss and dry matter loss rate of K326, burley and oriental tobaccos thereby. (2) After performing air-cured, sun-cured and flue-cured, the starch contents in the oriental and fluecured tobaccos greatly reduce while their contents of the total sugar and reducing sugar rose; the contents of starch and reducing sugar in the burley tobacco both decreased. (3) The contents of protein, total nitrogen and nicotine in the three types of air-cured, sun-cured and flue-cured tobaccos all significantly decreased. (4) The reduction amounts of the pigment content in the sun-dried burley and flue-cured tobaccos were the largest while that in the flue-cured oriental tobacco reaches the largest. (5) The total polyphenol contents in the three types of tobaccos all significantly reduced after being air-cured, sun-cured and flue-cured. The total polyphenol contents in the flue-cured and burley tobaccos were significantly larger than those in air-cured and sun-cured ones; the total polyphenol content in the sun-cured oriental tobacco was significantly larger than those in the groups treated with other curing methods. (6) The potassium (K) and chlorine (Cl) contents in the three types of tobaccos processed by the other curing methods were relatively stable. (7) The sensory evaluation scores of fluecured tobaccos, burley tobacco and oriental tobacco were higher after flue-cured based on Yunnan sensory evaluation method. The study clarifies the transformation law of chemical compositions in different types of tobaccos under different curing methods. A type of tobaccos is not only limited to single curing method. It is feasible to combine multiple curing methods to enrich the style characteristics of tobaccos.

Fructose 1,6-bisphosphate aldolase (FBA) as a key enzyme play crucial roles in glycolysis, gluconeogenesis and Calvin cycle processes in plants. However, limited information is known regarding FBA genes in Nicotiana tabacum. In this study, 16 FBAs were identified and characterized in Nicotiana tabacum. Phylogenetic analysis revealed that these genes can be categorized as type I (NtFBA1-10 located in chloroplast) and type II (NtFBA11-16 located in cytoplasm) subfamilies. According to the conserved motifs and gene structure analysis, NtFBA protein sequences had the highly homologous to FBAs in other species. Most members of the NtFBA gene family responded positively to NaHCO3 stress, especially the expression of NtFBA13/14 increased by 642%. In addition, the expression results of NtFBAs under five abiotic stress (light, NaCl, NaHCO3, drought, and cold) conditions were showed that NtFBA13/14 were highly up-regulated. qRT-PCR results showed that most of the NtFBAs expressed higher in leaves. NtFBA7/8 and NtFBA13/14 have important significance in photosynthesis and abiotic stress, respectively. This study provides a basis foundation for further elucidating the function of NtFBAs and the N. tabacum mechanism of resistance under abiotic stress.