Tobacco

Classification

The origin of the word “Nicotiana”, or nicotine, came from a French ambassador to Portugal called Jean Nicot de Villemain. In 1560 she became familiar with the plant and offered the seeds as a gift to Catherine de’ Medici. The plant soon called “herbe de l’ambassadeur” was cultivated in Paris and under her name Carl Linnaeus introduced the plant to botany. The specific epithet “tabacum” simply is translated to tobacco in English.

Classification information

Domain: Eukarya
Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Order: Solanales
Family: Solanaceae
Genus: Nicotiana
Species: Nicotiana tabacum

Domain: Eukarya

Tobacco is part of the domain Eukarya. The word eukarya can be broken down into “eu” meaning true, and “karya” meaning nucleus. Tobacco belongs to this domain because it is composed of eukaryotic cells, which contain a true nucleus and many membrane bound organelles.

Kingdom: Plantae

Tobacco is part of the kingdom Plantae because it is a green plant that harvests most of its energy from sunlight via photosynthesis.

Phylum: Magnoliophyta

Tobacco is part of the phylum Magnoliophyta which is a group that contains all of the seed bearing vascular plants or otherwise known as angiosperms.

Class: Magnoliopsida

Tobacco is part of the class Magnoliopsida because the plant contains seeds within closed capillary structures called ovaries resulting in flowers. The dicotyledonous plants are also grouped within this class and they all have primary and secondary vascular tissue to allow for secondary growth in the plant.

Order: Solanales

Tobacco is part of the order Solanales because of its toxic nicotine content. Plants in the order Solanales possess branched hairs, often spines, and commonly have alkaloids, like poison ivy, associated with them, which makes them poisonous.

Family: Solanaceae

Tobacco is part of the family Solanaceae because they are dicotyledonous plants that are in the “nightshade family”, with coffee, the potato, but interestingly enough not the sweet potato. These plants have been highly cultivated over the years for consumer use among people. Most of the plants in this family are herbaceous with terminal clusters of regular flowers usually borne in a cyme with estipulate leaves. There are usually five sepals, petals, and anthers in this family of plants.

Genus: Nicotiana

Tobacco is part of the Genus Nicotiana because it is a group of herbs and shrubs in the “nightshade” family and are cultivated and grown to produce tobacco.

Phylogenetic trees:

This phylogenetic tree reflects the taxonomic information above and shows the broad domain, kingdom, phylum, and class that tobacco fits under.

Tobacco’s journey first starts out in the Domain: Eukarya because it is composed of cells called eukaryotes that have a true nucleus accompanied by membrane-bound organelles.
Tobacco is then classified under the Kingdom: Plantae because it is a green plant that harvests most of its energy via photosynthesis and acts as a primary producer in its environment.

This phylogenetic tree depicts all of the angiosperms and their lineages.

Tobacco’s first divergence is to the eudicots which is morphological. Tobacco is considered to be in the eudicots because it contains flower parts in multiples of 4 or 5, possesses two cotyledons, has web-like veins in its leaves, has a main tap root, and the vascular tissues are arranged in a ring allowing for secondary growth. Monocots have flower parts in multiples of 3, possess only one cotyledon, has parallel veins in its leaves, does not possess a main tap root, and the vascular tissue is scattered throughout the stem allowing for only primary growth in the plant.
Tobacco’s second divergence is located at the asterids. Tobacco is considered to be a part of asterids I while the “Monkey Flower” is part of the asterids II. These two classes can be distinguished apart from each other morphologically by the fact that the asterids I appear to have the typical fused corolla derived independently which leads to the two different developmental pathways.
Tobacco’s third divergence is to the night shades or the Family: Solanaceae which can also be determined morphologically. The nightshades are a group of plants that have been highly cultivated over the years for consumer use among people. Most of the plants in this family are herbaceous with terminal clusters of regular flowers usually borne in a cyme, possessing estipulate leaves. There are usually five sepals, petals, and anthers in this family of plants.

This phylogenetic tree is of the Family: Solanaceae.

In the Family: Solanaceae, Nicotiana tabacum can be found as the third species from the top. The first plants found in the Solanaceae is coffee (Coffea arabica), which produces the drug called caffeine which I am sure you are all familiar with found in your morning cup.

The Petunia (Petunia axillaris) was once used as a hallucinogenic by early Indians giving them a feeling like “soaring through the air”, but is not nicotine which is where the plant tobacco (Nicotiana tabacum) fits into the picture.

Towards the bottom of the tree, potatoes can be found (Solanum). One can see how closely potatoes are related to tobacco. When using molecular data, the various alkaloids that each plant produces can be seen isolating them from each other.

Now that you know where tobacco fits in the grand scheme of things, lets look at the type of habitat you will find this plant occupying by clicking here!

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Logan Van Hoof, April 2011

Sequencing and assembly

Genome assembly of polyploid species, such as coffee (Coffea arabica), potato (Solanum tuberosum) and wheat (Triticum aestivum) is challenging. Even the assembly of the relatively small Brassica napus genome (1.2 Gb), which has well-annotated ancestral reference sequences, is still ongoing23. We sequenced the genomes of three inbred varieties of the allotetraploid N. tabacum, K326 (Flue-cured), TN90 (Burley) and Basma Xanthi (BX, Oriental), using a whole-genome shotgun sequencing approach with 100 bp Illumina HiSeq-2000 paired-end and mate-pair reads.

The size of the tobacco genome has been estimated to be 4.46 Gb by flow cytometry using the fluorochrome propidium iodide24 and 5.06 Gb by Feulgen microdensitometry13. Our estimations based on 17-mer depth distributions of raw sequencing reads25,26 were 4.41 Gb for N. tabacum TN90, 4.60 Gb for N. tabacum K326 and 4.57 Gb for N. tabacum BX. These represent a reduction of 4–8% of the tobacco genome compared with the sum of the ancestral N. sylvestris (2.59 Gb) and N. tomentosiformis (2.22 Gb), which is consistent with the previously published downsizing of 3.7% (ref. 13).

The genomes were assembled using SOAPdenovo 1.05 (ref. 27) with a k-mer of 63 by creating contigs from the variety-specific paired-end reads, scaffolding them with Nicotiana mate-pair libraries, closing the scaffolding gaps using variety-specific paired-end reads and filtering gap closing artifacts. The resulting final assemblies, described in Table 1, each amount to 3.7 Gb, representing a coverage of >80% of the tobacco genome. The remaining ~20% is likely to consist of repetitive regions that could not be resolved using the short read de novo shotgun approach. This represents a great improvement from the previous publicly available tobacco genome assembly ( ftp://ftp.solgenomics.net/tobacco_genome/assembly/), which contains 294,750 sequences (8.5% of the tobacco genome). We also sequenced libraries from N. otophora to investigate its contribution to N. tabacum.

Table 1 Assembly statistics of tobacco genomes.

We evaluated the quality of the scaffolding by mapping the assembly scaffolds to long BAC sequences (altogether 1.8 Mb) obtained from Nicotiana tabacum Hicks Broadleaf. We did not observe any sequence inversions due to scaffolding, and identified only three cases where a contig was not incorporated in a scaffold and remained as singleton (Supplementary Data 1). We also identified 13 cases of insertions or deletions. Altogether this represents 8.6 structural differences per megabase, if we assume that the Hicks Broadleaf sequence is the same as the TN90, K326 and BX sequence for the selected BACs.

The sequence-based Whole Genome Profiling (WGP) physical map was used to super-scaffold each genome assembly, and simple sequence repeats (SSRs) were mapped to super-scaffolded assemblies to anchor them to the 24 tobacco linkage groups. This resulted in 84% of the de novo assembly of TN90 being anchored to the WGP physical map (83 and 84% for K326 and BX, respectively), and 19% to the genetic map (17 and 16% for K326 and BX, respectively). Figure 1 shows the composition of the N. tabacum TN90 genome anchored to the linkage groups of the tobacco genetic map.

Figure 1: Tobacco genome.

Blue and red represent features of S and T origins in the Nicotiana tabacum TN90 genome, respectively. Track a indicates the origin of the linkage group previously determined by SSR amplification. Track b shows the assignment of the linkage group origin based on sequence identity with N. sylvestris, N. tomentosiformis and N. otophora. Track c shows the origin of the WGP physical map contig used for super-scaffolding. The blue, red and green histograms (tracks d, e and f, respectively) indicate the percentage of each 2 Mb region covered by an N. sylvestris, N. tomentosiformis or N. otophora sequence of at least 1,000 bp and 98% identity. Track g shows the density of coding regions identified by mapping of reference tomato proteins. Track h gives the position of SSR markers mapped to the genome sequences. The centre links regions of the N. tabacum genome based on sequence homology, as determined by reference tomato proteins mapping at two locations.

The three methods for assigning an ancestral origin to the linkage groups, SSR amplification in N. sylvestris and N. tomentosiformis20, sequence identity with donor species and using the WGP physical map21, are concordant. The latter two confirmed the previously reported colour inversion in linkage group 22 (ref. 21), and the central part of Fig. 1 clearly shows the correspondence between regions of different ancestral origins within regions of the N. tabacum genome linked by sequence homology.

By mapping SSR markers to the sequenced genomes of N. tabacum K326, TN90 and BX, we were able to predict SSR length differences between the three varieties. When comparing TN90 to K326, 57% of the predictions obtained exactly matched experimental measurements, and 10% had only 2-bp differences. The larger differences observed between experimental and in silico SSR measurements are likely to be caused by difficulties in resolving the SSR using short read assembly.

We used sequence identity to assign an ancestral origin to each 2-Mb region. The only region for which N. otophora appears as the most likely ancestor is at the end of linkage group 14 (Supplementary Fig. 1), indicating that if it contributed to the N. tabacum genome, then only marginally. This observation favours the hypothesis that the predominant paternal donor was N. tomentosiformis28.

We evaluated the completeness of our assemblies by mapping reference gene sequences to each genome using BLAT29 (Supplementary Table 1). For this we used NCBI and SGN tobacco Unigene constructs, as well as the SGN tobacco transcriptome30. We also used the coding sequences of tomato (ITAG v2.3) and potato (PGSC v3.4). We mapped 82–86% of the tobacco transcriptome; the remainder is likely to consist of genes spanning different genome sequences that have not yet been scaffolded. Between 50–59% of the Unigene constructs from NCBI and SGN could be mapped, presumably reflecting sequence diversity in the Unigene set31. Approximately 60% of the tomato and potato coding sequences could be mapped to the genomes, which compares favourably with the rate of transcript mapping to the Nicotiana benthamiana genome31 (56.5 and 58.5% for tomato and potato, respectively). In 92.8% of the cases, the best possible alignment of a tomato protein overlaps with a tobacco gene model from our TN90 transcriptome (nine tissues). The genetic and physical map anchoring results as well as alignment to the N. sylvestris and N. tomentosiformis genomes confirmed the quality of the three N. tabacum genome assemblies.

Synteny with other Solanaceae

The linkage groups from the genetic maps of both N. tomentosiformis and N. acuminata18, and the results of SSR amplification in N. tomentosiformis and N. sylvestris20, were used to show rearrangements that are found in tobacco (Supplementary Data 2 and 3). Figure 2 illustrates one such rearrangement, where part of linkage groups 4 and 8 of N. tomentosiformis are fused to give N. tabacum linkage groups 12 and 23, whereas N. acuminata linkage groups 4 and 8 did not fuse, and gave N. tabacum linkage groups 16 and 1, respectively.

Figure 2: Synteny between Nicotiana tabacum, Nicotiana tomentosiformis and Nicotiana acuminata genetic linkage groups and tomato chromosomes.

Links between tomato and tobacco are based on the mapping of tomato proteins to linkage group-anchored tobacco sequences. Note that not all regions identified by this method should necessarily be considered as syntenic. Links between tobacco and N. tomentosiformis (red) and N. acuminata (blue) are based on shared SSR (full lines) and COSII (dotted lines) markers. Triangles indicate the amplification of the corresponding SSR in N. tomentosiformis (red) or N. sylvestris (blue).

The synteny between the genomes of N. tabacum TN90, K326 and BX and those of tomato and potato was evaluated at the protein level by mapping tomato and potato proteins to tobacco sequences anchored to the linkage groups of the genetic map20 to detect homologous genes (Supplementary Data 2 and 3), and by detecting further homologous DNA blocks in genomes masked for repeats (Supplementary Data 4–7). Similar results were obtained using MCScanX32, which is a toolkit specifically designed for the detection and analysis of gene synteny and collinearity (Supplementary Data 8 and 9). Not all the regions identified by either of these methods should be considered as truly syntenic, as some of them rely only on a limited number of anchors. Likewise, additional syntenic regions are likely to exist, which cannot be detected by the methods used here. Nevertheless, these approaches confirm results reported earlier based on COSII (ref. 18) and SSR markers20.

Repetitive elements in the genomes

The repeat content of the N. tabacum K326, TN90 and BX genomes is summarized in Supplementary Table 2. Between 72 and 79% of the sequenced genomes are reported as repeat elements by RepeatMasker. This estimation is lower than that reported for barley (84%) and close to the original estimate (~80%) by Zimmerman11.

Based on the amount of the sequenced genome covered by repeats, we evaluated the DNA portion of the tobacco genome containing non-repeat coding regions to about 1 Gb. This is equivalent to the sum of the same DNA portion from the descendants of both ancestral genomes. The observed 4–8% reduction in genome size is thus likely to have occurred in the repetitive region of the genome. The sum of the genome sizes from the descendants of both ancestors is of 5.04 Gb, N. sylvestris accounting for 53% of it, and N. tomentosiformis for 47%. The tobacco scaffolds to which an origin could be assigned show 55–57% of S origin and 43–45% of T origin. The genome reduction thus is likely to have been more important in the T part of the genome than in the S part, which corresponds to what was reported by Renny-Byfield et al.12

The reported assemblies of three tobacco varieties cover >80% of the genome, which is comparable to that for smaller diploid genomes (76–90%)25,33 and for the smaller (3 Gb) allotetraploid N. benthamiana (81–87%)30,34. They represent some of the largest assembled plant genomes together with barley (5.1 Gb)35, Norway spruce (20 Gb)36 and the partial wheat genome (17 Gb)37. Contrary to other allotetraploid genomes, for which ancestral information is either not available (N. benthamiana) or limited (wheat), the ancestral origin of the tobacco sequences was identified and confirms previously reported assignments based on genetic markers20 and the physical map21.

Tobacco root and leaf transcriptome analysis

For each variety, three biological replicates were obtained from roots and leaves, which are two metabolically highly active tobacco tissues. In addition, nine tissues were sampled for TN90, so as to get good coverage of the gene regions. For each RNA-Seq sample, 86.5–94.7% of reads were mapped to the genome of the corresponding variety (Supplementary Table 3). Using RNA-seq data from two tissue types, we generated gene models for each of the three varieties, the gene number estimate being 81,000 for TN90 (Supplementary Table 4). Using data from nine tissue samples increases this estimate by 14.7% to >93,000 genes. Of the 134,694–188,510 transcripts, approximately half this number of unique open reading frames can be found (Supplementary Table 4). These numbers do not represent the whole transcriptome of tobacco, as we sampled RNA from only nine tissues, and hence will be missing transcripts not expressed in any of them. For the root and leaf transcriptomes, gene ontology (GO) terms could be assigned by InterProScan38 to ~40,000 proteins (from ~28,000 genes) (Supplementary Table 5); for the nine tissue samples, this number increases to >50,000, although there is notable increase in the number of unique GO terms assigned. A recent analysis of 454 N. sylvestris, N. tomentosiformis and N. tabacum next-generation sequencing transcriptomes showed neither differences in gene expression nor the creation of a new function for homoeologous genes between N. tabacum S- and T genomes30. Similarly, we found no new genes or new functionality of existing genes in the three varieties.

We analysed the GO term enrichment for differentially expressed genes in each tissue. Photosynthesis- and biosynthetic-related genes were highly expressed and enriched in leaf tissue, as were genes involved in oxidation–reduction processes (Supplementary Fig. 2). Root tissue has a very distinctive profile of upregulated genes (Supplementary Fig. 3). Besides lipid transport and regulatory gene overexpression, lignin and cell wall metabolism genes were prominent. Moreover, defence and oxidative stress response genes were heavily upregulated, which may be related to cell death processes apparent from the expression profile. The overexpression of ‘pollination’ genes reflects the electronic annotation of several upregulated proteins within the PFAM domain PF00954, the so-called ‘S locus glycoprotein-like’ domain. While this protein family is best known for being involved in the pollination process, some members are involved in defence response regulation39. It is thus more likely that the proteins identified here are involved in defence, rather than in pollination.

We used OrthoMCL to analyse the functional overlap between tobacco and three other, increasingly divergent plant species: N. benthamiana as a further representative of the Nicotiana genus, Solanum lycopersicum (tomato) as a further species in the Solanaceae family and Arabidopsis thaliana, another species in the eudicotyledons (Fig. 3). The bulk of the protein clusters are shared between all dicotyledons (10,362), we observed 2,024 and 4,044 clusters specific to N. benthamiana and N. tabacum, respectively, and 2,206 Nicotiana-specific clusters shared between both species. We also observed 3,706 clusters shared between all Solanaceae but not with Arabidopsis.

Figure 3: Protein clusters shared between tobacco and other increasingly more distant species phylogenetically.

Nicotiana benthamiana is a representative of the Nicotiana genus, Solanum lycopersicum (tomato) is a representative of the Solanum genus and Arabidopsis thaliana is a representative of the eudicotyledons.

Classical tobacco pathways

We extracted the sequences of biochemical pathway enzymes and observed copy numbers and expression in roots and leaves under different growth conditions (Supplementary Note 1). No major differences in gene expression were observed, but one new putrescine N-methyltransferase gene was identified in the alkaloid pathway in addition to the four already reported40. Furthermore, the two quinolinate phosphoribosyltransferase (QPT) genes of S origin were not found in N. tabacum K326 (Supplementary Table 6 and Supplementary Table 7). Most described alkaloid genes are expressed in roots where most alkaloids are synthesized; however, some transcripts from AO, QPT, QS and MPO genes were also detected in leaf, suggesting that they have different functions (Supplementary Fig. 4 and Supplementary Note 1).

In addition, we have mapped the putative steroidal alkaloid biosynthesis genes from Nicotiana genomes to the syntenic regions recently discovered on chromosomes 7 and 12 of S. lycopersicum41. In N. tabacum we identified two copies of each region, corresponding to their ancestral origin, indicating that these regions are conserved within Nicotiana species (Supplementary Fig. 5).

For Burley tobacco, which is known for its high nitrogen requirement, nitrogen assimilation is stronger than for Flue-cured tobacco (Supplementary Fig. 6). We therefore compared the number and expression levels of genes related with the glutamate/aspartate pathway (Supplementary Table 8 and Supplementary Note 2). With the exception of one AAT5 isoform missing in K326 but present in BX and TN90, we observed neither CNVs nor major transcriptomic variations, thereby suggesting that the nitrogen assimilation at the level of the glutamate/aspartate pathway is close between Burley tobacco and Flue-cured tobacco. However, it is not enough to conclude that the efficiency of ammonium assimilation is similar in both tobaccos, other downstream gene products from root to leaf being involved in the pathway as well as adaptations to environmental conditions. The analyses of the complete set of genes related to amino-acid assimilation will certainly help to understand the effect of human artificial selection on the high nitrogen requirement of Burley tobacco.

Disease resistance

TMV resistance was introduced in tobacco in the 1930s as a single dominant locus from an interspecific hybrid with Nicotiana glutinosa42,43,44. This locus was shown to harbour the N gene (NGU15605) encoding a (TIR)-NBS-LRR protein45 that triggers a hypersensitive response following recognition of the viral helicase46.

Among the three varieties sequenced here, only TN90 is TMV-resistant. TN90 has inherited the N gene from the variety Burley 21, which in turn inherited it from the variety Kentucky 56, which in turn inherited it from N. glutinosa hybrids47. Indeed, a search for the N. glutinosa N gene sequence in the draft assemblies showed weak identity in K326 and BX genomes (~90% identity on <35% of N. glutinosa genomic DNA), whereas a nearly perfect match was found for TN90 (99.9% identity over 7,158 bp).

PVY is a potyvirus, which is transmitted by aphids, and has a broad host range including potato and tomato. N. tabacum is naturally susceptible to PVY and other potyviruses such as TVMV and TEV; interestingly, the ancestors N. tomentosiformis and N. sylvestris are resistant and susceptible, respectively, to PVY. Most modern tobacco varieties bred for PVY resistance carry alleles of the Va locus. The recessive va allele, which was first obtained by deletion48 in the line TI 1406 (Virgin A Mutant) (Supplementary Note 3), confers resistance by preventing virus cell-to-cell movement in a similar way to the recessive resistances of pepper, potato and tomato, suggesting the involvement of a eukaryotic initiation factor49. The characterization of the PVY resistance gene using a recombinant inbred line population was recently presented by Julio et al.50 The eukaryotic translation initiation factor eIF4E was shown to be strongly expressed in susceptible plants, but not in resistant plants.

We carried out a sequence comparison of the genome of TN90, which is resistant to the potyviruses TVMV, TEV and PVY, and the genomes of K326 and BX, which are susceptible. We identified eIF4E1, eIF4E2 and eIF(iso)4E genes in the TN90, K326 and BX genome assemblies by first mapping corresponding tomato genes to N. sylvestris and N. tomentosiformis genomes, then mapping the respective genes to the tobacco genomes. One copy of each gene was found in the N. sylvestris genome, whereas two copies of eIF4E1 and one copy of the other genes were found in N. tomentosiformis. With the exception of the N. sylvestris eIF4E1 gene in TN90, all identified N. sylvestris and N. tomentosiformis genes were found in TN90, K326 and BX genomes. Gene-specific PCR verification (Supplementary Fig. 7) showed that the absence of the N. sylvestris eIF4E1 in TN90 is not an artefact of genome assembly, but rather that it is missing from this variety. This confirms the observation that TVMV, TEV and PVY resistance in TN90 is caused by genomic deletion of the S-form eIF4E1 locus50. This is in line with the pattern of resistance observed in tobacco ancestors, suggesting that the dominant sensitivity of N. tabacum to potyviruses via the eIF4E1 mechanism was conferred by N. sylvestris. The fact that both S and T copies of N. tabacum eIF4E1 are expressed concomitantly (Supplementary Table 9) allows us to speculate that either the interaction between the N. tomentosiformis eIF4E1 copies and viral proteins are compromised, or that the viral–host protein complex cannot provide the cell-to-cell movement required for systemic infection.

Nicotiana

A tall, upright annual for the middle of the border, that is loved for its strong heady fragrance. The main cultivars have a bold rosette of large leaves, from which rise tall branching flower stems. Dwarf forms are also available. Older varieties mainly flower in the evening, but modern hybrids bear flowers that open during the day.

Family: Solanaceae (nightshade family)
Botanical Name: Nicotiana
Common Names: Tobacco Plant
Foliage: Deciduous, simple large oval leaves.
Flowers: Starry, long-tubed, fragrant flowers, borne on tall branching stems. Available in a range of colours. Blooms change colour as they age.
Flowering Period: Early summer to early autumn.
Soil: Moist but well-drained soil (loam, chalk or clay) any pH.
Conditions: Best in full sun, will tollerate some shade. Plant in an south, west or east facing aspect, in a sheltered position
Habit: Upright, bushy.
Type: Can be annuals, biennials or perennials but generally grown as half-hardy annuals in the UK .
Origin: South America

Toxicity: Poisonous if ingested.

Hardiness: H2 – Half-hardy, protect from frost

Planting and Growing Nicotiana

Easy to grow. The best results are achieved in a fertile, well drained soil in full sun.

Tobacco plants mix well with other border flowers and give height to a border or bedding scheme. They also look good planted in loose drifts among shrubs or other taller plants.

Suitable for town and city gardens, cottage or informal gardens. Good for flower beds, borders, pots and containers.

Taking Care of Nicotiana

Keep the soil moist but not waterlogged. Feed with a liquid fertiliser every two weeks.

Pruning

No pruning necessary.

Pests and Diseases

Susceptible to aphids, leafhoppers and whitefly. Generally disease free.

Propagating Nicotiana

Sow the seeds under glass in late winter to early spring, at a temperature of 18°C (64°F). Sow on the surface, do not cover or exclude light. Prick-out, pot on, then plant-out at the end of May when all danger of frost is past. Space the plants 9-12in (23-30cm) apart.

Popular Varieties of Nicotiana Grown in the UK

Most hybrids and cultivars have been developed from Nicotiana alata.

‘Domino Mixed’, compact form, with flowers in red, pink, mauve, lilac, lime and white. Height 1ft (30cm).

‘Evening Fragrance’, has strongly scented flowers in pink, red, lilac, mauve and white. Height to 3ft (90cm).

‘Lime Green’, greenish yellow flowers. Height to 3ft (90cm).

‘Merlin’, a dwarf form in mixed colours, of crimson, white, lime-green and bicoloured purple. Height to 9in (23cm)

‘Nicki’, fragrant blooms in a mixture of colours from pink, white, red, mauve, maroon and lime-green. Height 1ft (30cm).

‘Roulette’, mixture of flower colours, over bright green foliage. Height 1ft (30cm).

‘Sensation Mixed’ has flowers in a wide range of colours. Height 2.5ft (75cm).

Nicotiana Flowering Tobacco – How To Grow Nicotiana Flowers

Growing nicotiana in the ornamental flower bed adds a variety of color and form. Excellent as a bedding plant, smaller cultivars of the nicotiana plant reach only a few inches, while others may grow as tall as 5 feet. Various sizes of the nicotiana flower can be used at the front or back of a border and provide a sweetly fragrant experience on calm days and especially in the evening.

Flowers of nicotiana, flowering tobacco (Nicotiana alata), are tubular shaped and grow moderately to quickly. Too much fertilization when growing nicotiana can lead to excessive growth of the petite plants causing them to get leggy and cease flowering or flop.

Growing the Nicotiana Plant

Nicotiana flowering tobacco is most often grown and sold as an annual plant although some species of the nicotiana flower are really a short lived perennials. Plant seeds or seedlings into a sunny or partially shaded area of the garden with well drained soil in late spring

Some species of the nicotiana flower may be short-lived, providing attractive blooms for the early days of summer. Others may bloom until taken by frost. Be prepared to replace the nicotiana plant with a hot weather annual or perennial.

The blooming nicotiana flower is worthwhile as attractive 2 to 4 inch blooms decorate your sunny locations. Borne in clusters on multi-branching stems, the nicotiana flower grows in shade of white, pink, purple and red. There is also the lime-green petaled nicotiana flower of the Saratoga rose cultivar.

Care of the nicotiana plant is basically watering and deadheading spent flowers to encourage the return of more brilliant blooms. While this plant will tolerate some drought, optimum flowering occurs in moist soil.

Cultivars of Nicotiana Plant

67 cultivars of flowering tobacco exist. Foliage of the nicotiana plant can be large, making the plant bushy.

  • The cultivar Alata has leaves which may grow to 10 inches, with up to 4 inch blooms. This is one of the most fragrant of the varieties.
  • Sylvestris may reach a height of 3 to 5 feet with fragrant white flowers.
  • The Merlin series reaches only 9 to 12 inches and is appropriate for use in a front border or as part of a container planting.

Nicotiana sylvestris

The 67 species of Nicotiana hail from Australia, North America, and tropical South America. All have tubular or trumpet-shaped flowers that usually open in the evening and at night, sometimes releasing a potent fragrance. They can be used as specimen or bedding plants, in borders, woodland gardens or containers. Heights range from less than 1 foot to over 10 feet.

Noteworthy CharacteristicsLong-blooming, attractive plants with trumpet-shaped flowers in shades of green, white, red, and pastels. Some species have attractive foliage. Fairly easy to grow from seed. Contact with the hairy foliage may irritate skin.

CareFull sun to part shade in fertile, moist soil with good drainage. Stake plants that are not grown in sheltered locations.

PropagationTo get Nicotianas going, you could just scatter seed in early spring, but you won’t get much of a display until August. For earlier blooms, start the minuscule seeds inside 8 to 10 weeks before the last frost date at 64°F. Seeds should be surface-sown since they need light to germinate. In 10 days or so, the seeds sprout and soon form attractive little rosettes. Leaves yellow quickly if the seedlings get hungry. Feed with a weekly draught of fish emulsion and water-soluble 20-20-20 fertilizer, using each at half strength. As the frost-free date nears, gradually acclimate seedlings to life outdoors. By early summer, nicotianas started indoors should be in bloom. Many species self-sow.

ProblemsOnce up and running, plants are essentially problem-free, though aphids sometimes favor woodland tobacco, and many species are prone to slug attacks in moist, shady sites. Also possible are viruses, stem rot, stalk rot, downy mildew, damping off and root rot, as well as caterpillars, leaf miners and spider mites.

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