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Defining phylogenetic relationship of Nepeta x tmolea and its parents via DNA barcoding
expand article infoTaner Özcan
‡ Balıkesir University, Balıkesir, Turkey
Open Access

Abstract

Nepeta viscida and N. nuda subsp. nuda and N. × tmolea were examined in this study. Mainly fresh leaf pieces, dried with silica grains, were used for DNA extraction procedures via DNA isolation kits. Standard PCR techniques were executed using three different primer sets (one nuclear DNA region (nrITS) and two chloroplast DNA regions (rpl32-trnL and trnA(Leu)-trnA(Phe)-trnL-F). DNA sequences were analysed and evaluated using different molecular approaches and software. Consequently, the inconstant molecular structure and hybrid nature of N. × tmolea specimens were shown and interpreted in this study. According to our result, N. × tmolea have some intermediate characters compared to its parents. nrITS data give more information phylogenetically, and also the most polymorphic loci are seen in nrITS data. Morphological and molecular data contribute to define separation of N. × tmolea. Consequently, the inconstant molecular structure and hybrid nature of N. × tmolea specimens were shown and interpreted in this study.

Keywords

hybrid, molecular, Nepeta, phylogeny, Turkey

Introduction

Lamiaceae family – the mint family – members are well known for their medicinal and aromatic properties in the pharmaceutical industry. The Nepeta L. genus is mainly native to Europe, Western Siberia, Far East and North Asia and consists of approximately 300 species with its being one of the largest genera in Lamiaceae (Pojarkova 1954; Hedge 1986; Jamzad et al. 2000, 2003b; Tzakou et al. 2000; Mojab et al. 2009). In recent studies, Turkish Nepeta members have been represented by 44 species. Twenty-two of these species are endemic to Turkey (Aytaç and Yıldız 1996; Güner et al. 2000; Dirmenci 2003) with the distribution areas of the species being mainly in east Anatolia and the Taurus Mountains in Turkey (Dirmenci 2005). Nepeta nuda L. subsp. nuda is a widespread and well-known subspecies of N. nuda in Turkey with its distinguishing characters of violet-blue calyx and corolla (Hedge and Lamond 1982; Dirmenci 2003). Nepeta nuda subsp. nuda and N. viscida Boiss. are members of Group A, according to the Flora of Turkey classification (Hedge and Lamond 1982; Dirmenci 2003). Nepeta viscida is readily separated from N. nuda subsp. nuda by its viscous glandular trichomes and general habit.

It is mentioned in the Flora of Turkey that N. viscida hybridises with N. nuda in overlapping areas and forms the hybrid described as N. × tmolea Boiss. (Hedge and Lamond 1982). In the field trips during this study, we found some N. nuda subsp. nuda and N. viscida individuals that reflect their typical characters. Some individuals had, however, some intermediate morphological characters: they were not viscid and their stem, leaf and corolla colours were quite different from N. nuda subsp. nuda and N. viscida. Thus, we recognised these specimens as N. × tmolea. Some N. × tmolea hybrid individuals were more similar to N. viscida in terms of general habits, calyx and leaf characters; on the other hand, some samples were more similar to N. nuda subsp. nuda in terms of their bluish colour on the verticillasters and their having no adhesive glandular trichomes.

According to literature, trichome types, density, presence/absence etc. are very important characters for identifying different taxa in the Lamiaceae family (Husain et al. 1990; Ecevit-Genç et al. 2015, 2017, 2018; Krawczyk and Głowacka 2015; Sajna and Sunojkumar 2018) and, of course, the genus Nepeta (Kolalite 1988; Dirmenci 2003; 2005; Kaya et al. 2007; Açar et al. 2011; Yarmoohammadi et al. 2017; Özcan 2019). Additionally, it is mentioned in the studies that, although the type and density of trichomes are distinctive amongst species, they can vary in different organs of the same individual.

DNA barcoding methods have been frequently used in differentiating taxa in recent years (Hebert et al. 2003). Specimens can be separated by obtaining a standard DNA region using a very small sample (Kress and Erickson 2007). According to Jamzad et al. (2003a), nuclear ITS DNA sequences are correlated with some morphological characters and, thus, this region can be helpful in defining the phylogenetic positions of the Nepeta species. Molecular approaches are also used to reveal heterozygotic and polymorphic structures of some hybrid taxa belonging to the Lamiaceae family in literature (Bariotakis et al. 2016; Kokubugata et al. 2011; Jedrzejczyk 2018; Dirmenci et al. 2018a, 2018b, 2019a). Some Single Nucleotide Polymorphisms (SNPs), which are are the most common type of genetic variation among plants and meaning replacing of a nucleotide (i.e. C) to another (i.e.T) in a certain stretch of DNA, were identified in this study.

This research aimed to reveal the phylogenetic relationships and heterozygous DNA structure of Nepeta nuda subsp. nuda, N. viscida and their hybrid N. × tmolea. The internal transcribed spacers of nuclear ribosomal DNA (nrITS), trnL-F and rpl32 regions from chloroplast DNA were examined to define heterozigoty of DNA sequences amongst parents and hybrid specimens.

Materials and methods

Plant materials

The different individuals of N. viscida, N. × tmolea and N. nuda subsp. nuda were collected during the field trips (2016–2018) from their natural habitats in Balıkesir (Dursunbey-Çamlık) (Fig. 1), İzmir (Ödemiş-Bozdağ) and from Kütahya in 2002. Voucher specimens are deposited in the Herbarium of Necatibey Education Faculty of Balıkesir University in Balıkesir, Turkey.

Figure 1. 

General habit, inflorescence and lower parts of N. nuda subsp. nuda (A, D, G); N. × tmolea (B, E, H) and N. viscida (C, F, I).

DNA isolations

DNA isolations were performed using the DNeasy Plant Mini Kit (QIAGEN, Germany), following the manufacturer’s instructions with some modifications. Eight different N. × tmolea specimens and different specimens of N. viscida and N. nuda subsp. nuda were used for DNA isolations. Taxon name, voucher number and localities are given in Table 1.

Voucher information of Nepeta species examined for DNA extractions.

Taxon Voucher number Locality
N. viscida 4759 Balıkesir: Dursunbey, Alaçam Mount., Gölcük, around Karaveli Hill, 39.42650N, 28.53057E, 4970 ft alt., 19/06/2017.
4762 Balıkesir: Dursunbey, Alaçam Mount., Sokuldak area, 39.43673N, 28.51373E, 4790 ft alt., 19/06/2017.
4766 İzmir: Ödemiş, around Bozdağ ski resort, 20/06/2017.
4768 İzmir: Ödemiş, around Bozdağ ski resort, 20/06/2017.
5024 Balıkesir: Dursunbey, Alaçam Mount., around Karaveli Hill, 39.42625N, 28.53123E, 4930 ft alt., 11/06/2018.
5027 Balıkesir: Dursunbey, Alaçam Mount., around Karaveli Hill, 39.42682N, 28.52975E, 4960 ft alt., 11/06/2018.
5030 Balıkesir: Dursunbey, Alaçam Mount., Sokuldak area, 39.43662N, 28.51364E, 4780 ft alt., 11/06/2018.
N. × tmolea 4758 Balıkesir: Dursunbey, Alaçam Mount., Gölcük, around Karaveli Hill, 39.42650N, 28.53057E, 4970 ft alt., 19/06/2017.
4761 Balıkesir: Dursunbey, Alaçam Mount., Sokuldak area, 39.43673N, 28.51373E, 4790 ft alt., 19/06/2017.
4765 İzmir: Ödemiş, around Bozdağ ski resort, 20/06/2017.
4770 İzmir: Ödemiş, around Bozdağ ski resort, 20/06/2017.
5023 Balıkesir: Dursunbey, Alaçam Mount., around Karaveli Hill, 39.42625N, 28.53123E, 4930 ft alt., 11/06/2018.
5026 Balıkesir: Dursunbey, Alaçam Mount., around Karaveli Hill, 39.42682N, 28.52975E, 4960 ft, 11/06/2018.
5029 Balıkesir: Dursunbey, Alaçam Mount., Sokuldak area, 39.43662N, 28.51364E, 4780 ft alt., 11/06/2018.
1073 Balıkesir: Dursunbey, above Tahtalık Hill, 5413 ft alt., 07/05/2000.
N. nuda subsp. nuda 4757 Balıkesir: Dursunbey, Alaçam Mount., Gölcük, around Karaveli Hill, 39.42650N, 28.53057E, 4970 ft alt., 19/06/2017.
4764 İzmir: Ödemiş, around Bozdağ ski resort, 20/06/2017.
4769 İzmir: Ödemiş, around Bozdağ ski resort, 20/06/2017.
5021 Balıkesir: Dursunbey, Alaçam Mount., Soğucak area, 39.45649N, 28.53786E, 3818 ft alt., 11/06/2018.
5022 Balıkesir: Dursunbey, Alaçam Mount., around Karaveli Hill, 39.42625N, 28.53123E, 4930 ft alt., 11/06/2018.
5025 Balıkesir: Dursunbey, Alaçam Mount., around Karaveli Hill, 39.42682N, 28.52975E, 4960 ft alt., 11/06/2018.
5028 Balıkesir: Dursunbey, Alaçam Mount., Sokuldak area, 39.43662N, 28.51364E, 4780 ft alt., 11/06/2018.
1940 Kütahya: Radar road, 3935–4920 ft alt., 07/10/2002.

PCR amplification

In this study, molecular analyses of N. × tmolea, N. viscida and N. nuda subsp. nuda were carried out using three different DNA regions: the nuclear internal transcribed spacer (nrITS), trnA (Leu)-trnA (Phe) (trnL-F) and rpl32-trnL regions of the chloroplast DNA (cpDNA). PCR amplification of the ITS nrDNA were performed using ITS5a (5'-CCT TAT CAT TTA GAG GAA GGA G-3') (Stanford et al. 2000) and ITS4 (5'-TCC TCC GCT TAT TGA TAT GC-3') (White et al. 1990) primers. The rpl32- trnL cpDNA amplifications were performed using rpl32-F (5'-CAG TTC CAA AAA AAC GTA CTT C-3') (Shaw et al. 2007) and trnL (UAG) (5'-CTG CTT CCT AAG AGC AGC GT-3') (Shaw et al. 2007) primers and the trnL-F amplifications were performed with trnL-c (5’-CGA AAT CGG TAG ACG CTA CG-3’) (Taberlet et al. 1991) and trnL-f (5’-ATT TGA ACT GGT GAC ACG AG-3’) (Taberlet et al. 1991) primers.

DNA data analysis

The PCR products that were successfully amplified and checked on agarose gel were sent to Genoks (Gene Research and Biotechnology Company, Turkey) for sequencing. Raw sequenced DNA data files were edited via Sequencer version 5.4 (Gene Codes Corporation, Ann Arbor, MI, USA) and edited sequences were aligned using Bioedit 7.2.5 (Hall 1999). The polymorphic sequence loci and heterozygous structure of N. viscida, N. × tmolea and N. nuda subsp. nuda were identified and polymorphisms of these specimens were demonstrated by selected software. Successfully sequenced specimens were given in Table 1. Phylogenetic cladograms were constructed using PAUP* 4.0a165 (Swofford 2003) and Dendroscope (Huson and Scornavacca 2012), and a Neighbour-Net split graph was conducted using SplitsTree 4.14 (Huson and Bryant 2006). A data matrix was constructed according to discriminative characters belonging to rpl32 DNA data. In addition, discriminant analysis was carried out with PAleontoSTatistics (PAST) (Hammer et al. 2001) to show the position of individuals in these studies.

Results

N. viscida is easily morphologically distinguished from N. nuda subsp. nuda by its sticky stem and leaves. These sticky structures, resulting from viscous glandular trichomes, are highly characteristic for N. viscida in Nepeta genus (Dirmenci 2003; Özcan 2019). Although this morphological feature is very significant, N. viscida and N. nuda subsp. nuda taxa are classified under Group A (Hedge and Lamond 1982; Dirmenci 2003). According to the Flora of Turkey, N. viscida and N. nuda belong to Group A along with N. cataria L., N. isaurica Boiss. & Heldr. ex Benth. and N. caeserea Boiss. Özcan (2019) stated that N. × tmolea is quite different from its parents but micromorphologically more similar to N. nuda subsp. nuda. The indumentum is a distinctive character for distinguishing N. viscida and N. nuda subsp. nuda. As with many hybrids (Clevinger and Panero 2000; Baumel et al. 2002; Lowe and Abbott 2004; Liu et al. 2017; Szczecińska et al. 2017; Jaźwa et al. 2018; Van Valkenburg et al. 2018; Dirmenci et al. 2019b), N. × tmolea hybrid individuals show transition/intermediate characteristics between N. viscida and N. nuda subsp. nuda. However, some specimens of N. × tmolea have higher similarities to N. nuda subsp. nuda, while others have high morphological similarities to N. viscada. Namely, N. × tmolea is distinguished from N. nuda subsp. nuda by its bracteoles 5–10 mm (not 2.5–4 mm), calyices 6–9 mm (not 3.5–4 mm), calyx teeth 3.5–5 mm (not 1.5–2 mm), corolla 7.5–10 mm (not 5.5–6.5 mm). Also, it differs from N. viscida by its bracteoles 5–10 mm (not 8.5–11 mm), calyices 6–9 mm (not 8.5–12 mm), calyx teeth 3–5 mm (not to 6.5 mm), and corolla 7.5–10 mm (not 9–13 mm).

We used three different loci, one nuclear DNA loci-nrITS- and two DNA loci from chloroplast genome-rpl32-trnL and trnA(Leu)-trnA(Phe)- in this study.

Nuclear DNA data

In total, 21 taxa were sequenced for the ITS sequence matrix. In the parsimony heuristic search, consistency, retention and homoplasy indices were identified as 0.75, 0.78 and 0.25, respectively. According to Fig. 2, N. viscida and N. nuda subsp. nuda are sister taxa and belong to the same clade in comparison to other Group A members with a strong bootstrap value (86). When Fig. 1B is analysed, the N. viscida-N. nuda subsp. nuda group has a close relationship with N. kurdica Hausskn. & Bornm., N. fissa C.A.Mey, N. scrophularioides Rech.f. and N. lamiifolia Adam ex G.F.Hoffm. When the nrITS sequences of N. × tmolea and its parents are compared, N. × tmolea has 8 single nucleotide polymorphisms (Table 2). As mentioned above, N. × tmolea has some intermediate characters between its parents, such as leaf size and indumentum density, and our DNA data contribute further with the morphological characters. N. nuda subsp. nuda (1940) and N. nuda subsp. nuda (4764 and 4769) individuals (distributing in Ödemiş, see Table 1) differed the specimens from Balıkesir-Dursunbey (4757 and 5021). Thus, nrITS data also gave us intra-individual differentiations.

Figure 2. 

Phylogenetic position of N. viscida and N. nuda subsp. nuda amongst different Nepeta species and outgroups (based on nrITS sequences and Maximum Likelihood phylogram (A) and Neighbour-Net Diagram (B) without hybrids.(* examined taxa in this study).

All the nrITS DNA data included 594 characters; 579 of 594 characters were constant, 6 variable characters were parsimony uninformative and 9 of the rest were parsimony informative (Table 2). Nepeta viscida 5024-4, 5024-2 and 5030-1 specimens have different nucleotides at the nucleotide positions of 11, 353, 420, and 462 in comparison to N. viscida 5024-1, 5030-3 and 5024-3 specimens, which are distributing in the same location (Dursunbey). In addition, the most heterozygous individual, N. viscida 5024-3 has heterozygote nucleotide polymorphisms at positions 355, 420 and 462. The most polymorphic locus is seen at position 421 (C-T nucleotide heterozygous - in bold characters) for all the specimens. On the other hand, all the examined taxa have polymorphic loci, according to nrITS data. These heterozygote sequences may be the result of continuous crossing between N. viscida and N. nuda subsp. nuda and backcrossing amongst the parents and N. × tmolea. Additionally, it can be seen from the Table 1 that, not only studied N. viscida members (7 specimens), but also N. nuda subsp. nuda (5 specimens) members have heterozygous structures, not only constant characters, at the given nucleotide positions.

Separated loci of N. viscida, N. nuda subsp. nuda and N. × tmolea based on nrITS data.

1 4 1 3 4 4 4 4 5
1 3 2 5 2 2 6 7 3
0 5 0 1 2 4 1
Nepeta viscida 5024 4 C C T T G T T G C
Nepeta viscida 5024 2 C C G T G C/T T G/T C
Nepeta viscida 5030 1 C C G T G C/T T T C
Nepeta viscida 5024 1 A C G A T T A G C
Nepeta viscida 5030 3 A A G A T T A G C
Nepeta viscida 5024 3 A C G A/T G/T T A/T G C
Nepeta viscida 4759 A C G A/T G T T G C
Nepeta × tmolea_4758 A C G A G C/T A/T G T
Nepeta × tmolea_5023 3 C C T T G T T G C
Nepeta × tmolea_5023 2 C C T T G T T G/T C
Nepeta × tmolea_4761 C C G T G C/T T G/T C
Nepeta × tmolea_1073 C A G T G C/T T T C
Nepeta × tmolea_5029 2 C A G T G C/T T T C
Nepeta nuda subsp. nuda 5021 C C T T G T T G C
Nepeta nuda subsp. nuda 4757 C C G A/T G T A/T G T
Nepeta nuda subsp. nuda 1940 C C G A/T G T A/T G T
Nepeta nuda subsp. nuda 4769 C C G T G C/T T G/T C
Nepeta nuda subsp. nuda 4764 C A G A/T G C/T T G/T C

According to nrITS sequences, different N. × tmolea specimens are classified with different parents (Fig. 3). Five main clades can be seen in Fig. 2. Two parents and their putative hybrid specimens share the same clade at clades 4 and 5, N. nuda subsp. nuda and N. × tmolea are more similar at clades 2 and 3. Therefore, it can be considered that the phylogenetic position of N. × tmolea is not constant and that ancestral species show transitions in different clades. When the hybrid individuals are not included in the phylogenetic analysis, N. viscida and N. nuda subsp. nuda tend to be closer to individuals of their own species, but ancestral species are divided into different clades after adding hybrid sequences in the analysis.

Figure 3. 

Phylogenetic relationship of N. viscida, N. nuda subsp. nuda and N. × tmolea with some Nepeta members and outgroups (based on nrITS sequences and Neighbour Joining phylogram (A) and Dendroscope diagram (B).(* examined taxa in this study).

Chloroplast DNA data

rpl32-trnL and trnL-F DNA regions were examined from the chloroplast genome. The longest data of studied regions were obtained from rpl32-trnL sequences. A total of 891 nucleotides were obtained from 29 specimens belonging to the parents and hybrid taxa; 855 of 891 characters were constant and parsimony-informative characters were 31. On the other hand, 847 characters were obtained from 32 specimens belonging to the parents and hybrid taxa, 833 of which were constant and 10 characters of the rest of the sequences were parsimony-informative for the trnL-F region.

When we analyse Fig. 4, the phylogenetic tree and PCA diagram show us the transition amongst the species and hybrid individuals. This means that neither N. viscida nor N. nuda subsp. nuda specimens are monophyletic. Some clades have only one putative ancestor and hybrid and some of them have parents and hybrid taxa. These three taxa are mixed together and grouped at different clades in the cladogram (Fig. 4A) or at different regions in the PCA diagram (Fig. 4B). In addition, three N. × tmolea samples have completely similar DNA sequences with three N. nuda subsp. nuda samples and this can also be seen from the PCA diagram (with black arrows) (Fig. 4B).

Figure 4. 

Dendroscope cladogram and PCA diagram based on rpl32-trnL data.

Single nucleotide polymorphisms (SNPs) were mostly seen in rpl32 data. G-T polymorphisms at positions 22, 41, 135, A-G polymorphisms at positions 24, 160, 311, A-C polymorphisms at positions 45, 331, 334 and C-T polymorphism at position 758 are significant for distinguishing specimens. Insertion-deletion sites are very significant, especially at the nucleotide positions between 140–150, 312–314, 325–328, 340–353, 603–608 and the longest one between positions 764–810 (Fig. 5).

trnL-F has also some SNPs at the nucleotide positions of 244, 596 and 696. Insertion-deletion (I-D) sites in trnL-F data are shorter than rpl32 data. There are three parsimony-informative I-D regions around the nucleotides 260, 410 and 600 (Fig. 6). Unfortunately, insertion or deletion sites were not parsimony informative for our finding out phylogenetic position of the species.

Figure 5. 

Insertions, deletions and single nucleotide polymorphisms based on rpl32-trnL sequences.

Figure 6. 

Insertions, deletions and single nucleotide polymorphisms based on trnL-F sequences.

Conclusions

Possible hybridisation between N. nuda subsp. nuda and N. viscida was estimated by Boissier (1859) for the first time but N. × tmolea was not presented as a hybrid. According to morphological studies, although general habitus, calyx and leaf characters of N. × tmolea are more similar to N. viscida, its indumentum (especially glandular trichome) is very different and separated. Molecular data overlaps with morphological data. As in the morphological data, hybrid individuals have intermediate characters in DNA sequences, and these characters occur as polymorphic loci.

DNA sequences, especially nrITS data, have been used by many scientists to discover the phylogenetic position and relationship of numerous species in literature. In this study, nrITS gave information about SNPs and rpl32-trnL and trnL-F were used to specify the parents’ taxa N. × tmolea. Having some polymorphic loci of N. nuda subsp. nuda (Table 2) has probably caused introgression. Hybrid forming areas (Dursunbey and Ödemiş districts) of N. nuda subsp. nuda and N. viscida are mostly contacted and formed N. × tmolea. In these hybrid swarm regions, N. × tmolea individuals possibly do backcrossing with its parents. Additionally, because of this backcrossing, some N. nuda subsp. nuda specimens have different nucleotides from the other N. nuda subsp. nuda samples which are the original parental individuals. According to literature, while chloroplast DNA gives us information about maternal or paternal inheritance, this study did not provide a completely reasonable result based on rpl32-trnL and trnL-F data.

In addition, we could not see logical clustering among the specimens growing in the same location (Dursunbey or Ödemiş), and nrITS data also gave us intra-individual differentiations of N. viscida and N. nuda subsp. nuda.

Acknowledgements

This study was supported by the Balıkesir University Research Foundation Centre (project number: 2017/144). I am also very appreciative to Dr. Tuncay Dirmenci for helping to collect plant specimens and his valuable comments on morphological features and phylogenetic relationships of the species.

References

  • Açar M, Özcan T, Satıl F, Dirmenci T (2011) A comparative anatomical study on two endemic Nepeta L. species (N. baytopii and N. sorgerae). Biological Diversity and Conservation 4: 58–70.
  • Aytaç Z, Yıldız G (1996) A new record for the Flora of Turkey. Turkish Journal of Botany 20: 385–386.
  • Bariotakis M, Koutroumpa K, Karousou R, Pirintsos SA (2016) Environmental (in)dependence of a hybrid zone: Insights from molecular markers and ecological niche modeling in a hybrid zone of Origanum (Lamiaceae) on the island of Crete. Ecology and Evolution 6(24): 8727–8739. https://doi.org/10.1002/ece3.2560
  • Baumel A, Ainouche ML, Bayer RJ, Ainouche AK, Misset MT (2002) Molecular phylogeny of hybridizing species from the genus Spartina (Poaceae). Molecular Phylogenetics and Evolution 22(2): 303–314. https://doi.org/10.1006/mpev.2001.1064
  • Boissier PE (1859) Diagnoses Plantarum Orientalium Novarum vol. 2(4). Liepzig & Paris, 146 pp.
  • Clevinger JA, Panero JL (2000) Phylogenetic analysis of Silphium and subtribe Engelmanniinae (Asteraceae: Heliantheae) based on ITS and ETS sequence data. American Journal of Botany 87(4): 565–572. https://doi.org/10.2307/2656600
  • Dirmenci T (2003) Taxonomical researches on Nepeta L. (Lamiaceae) species growing in Turkey. PhD Thesis, Balıkesir University, Balıkesir.
  • Dirmenci T, Yazıcı T, Özcan T, Çelenk Ç, Martin E (2018a) A new species and a new natural hybrid of Origanum L. (Lamiaceae) from the west of Turkey. Turkish Journal of Botany 42: 73–90. https://doi.org/10.3906/bot-1704-35
  • Dirmenci T, Özcan T, Yazıcı T, Arabacı T, Martin E (2018b) Morphological, cytological, palynological and molecular evidence on two new hybrids: An example of homoploid hybridization in Origanum (Lamiaceae). Phytotaxa 371(3): 145–167. https://doi.org/10.11646/phytotaxa.371.3.1
  • Dirmenci T, Özcan T, Açar M, Arabacı T, Yazıcı T, Martin E (2019a) A rearranged homoploid hybrid species of Origanum (Lamiaceae): O. × munzurense Kit Tan & Sorger. Botany Letters 166(2): 153–162. https://doi.org/10.1080/23818107.2019.1585283
  • Dirmenci T, Özcan T, Arabacı T, Çelenk S, İsmailova G, Yıldız B (2019b) Hybridization among three Cirsium (Asteraceae) species and important evidence for three new hybrids from Turkey. Turkish Journal of Botany 43(3): 366–385. https://doi.org/10.3906/bot-1806-53
  • Ecevit-Genç G, Özcan T, Dirmenci T (2015) Micromorphological characters on nutlet and leaf indumentum of Teucrium sect. Teucrium (Lamiaceae) in Turkey. Turkish Journal of Botany 39: 439–448. https://doi.org/10.3906/bot-1406-18
  • Ecevit-Genç G, Özcan T, Dirmenci T (2018) Leaf indumentum in some Turkish species of Teucrium (Lamiaceae). Istanbul Journal of Pharmacy 48: 6–11.
  • Güner A, Özhatay N, Ekim T, Başer KHC (2000) Flora of Turkey and the East Aegean Islands. Edinburgh: Edinburgh University Press, Vol. 11.
  • Hall TA (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series 41: 95–98.
  • Hammer Q, Harper DAT, Ryan PD (2001) Past: Paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4: 1–9.
  • Hebert PDN, Cywinska A, Ball SL, DeWaard JR (2003) Biological identifications through DNA barcodes. Proceedings of the Royal Society of London. Series B, Biological Sciences 270(1512): 313–321. https://doi.org/10.1098/rspb.2002.2218
  • Hedge IC, Lamond JM (1982) Nepeta L. In: Davis PH (Ed.) Flora of Turkey and East Aegean Islands, Vol. 7. Edinburgh University Press, Edinburgh, 264–288.
  • Husain SZ, Marin PD, Šilić Č, Qaiser M, Petcović B (1990) A micromorphological study of some representative genera in the tribe Saturejeae (Lamiaceae). Botanical Journal of the Linnean Society 103(1): 59–80. https://doi.org/10.1111/j.1095-8339.1990.tb00174.x
  • Huson DH, Scornavacca C (2012) Dendroscope 3- An interactive viewer for rooted phylogenetic trees and networks. Systematic Biology 61(6): 1061–1067. https://doi.org/10.1093/sysbio/sys062
  • Jamzad Z, Harley MM, Ingrouille M, Simmonds MSJ, Jalili A (2000) Pollen exine and nutlet surface morphology of the annual species of Nepeta L. (Lamiaceae) in Iran. In: Harley MM, Morton GM, Blackmore S (Eds) Pollen and Spores: Morphology and Biology. Royal Botanic Gardens, Kew, 385–397.
  • Jamzad Z, Chase MW, Ingrouille M, Simmonds MSJ, Jalili A (2003a) Phylogenetic relationships in Nepeta L. (Lamiaceae) and related genera based on ITS sequence data. Taxon 52(1): 21–32. https://doi.org/10.2307/3647435
  • Jaźwa M, Jedrzejczak E, Klichowska E, Pliszko A (2018) Predicting the potential distribution area of Solidago × niederederi (Asteraceae). Turkish Journal of Botany 42: 51–56. https://doi.org/10.3906/bot-1703-17
  • Kaya A, Demirci B, Başer KHC (2007) Micromorphology of glandular trichomes of Nepeta congesta Fisch. & Mey. var. congesta (Lamiaceae) and chemical analysis of the essential oils. South African Journal of Botany 73(1): 29–34. https://doi.org/10.1016/j.sajb.2006.05.004
  • Kokubugata G, Kurihara T, Hirayama Y, Obata K (2011) Molecular Evidence for a Natural Hybrid Origin of Ajuga × mixta (Lamiaceae) Using ITS Sequence. Bulletin of the National Museum of Nature and Science. Series B, Botany 37: 175–179.
  • Kolalite MR (1988) Comparative analysis of ultrastructure of glandular trichomes in two Nepeta cataria chemotypes (N. cataria and N. cataria var. citriodora). Nordic Journal of Botany 18(5): 589–598. https://doi.org/10.1111/j.1756-1051.1998.tb01542.x
  • Liu Q, Liu H, Wen J (2017) Relationships between Sorghum bicolor (Poaceae) and its close relatives based on genomic in situ hybridization evidence. Turkish Journal of Botany 41: 11–24. https://doi.org/10.3906/bot-1606-8
  • Mojab F, Nickavar B, Hooshdar TH (2009) Essential Oil Analysis of Nepeta crispa and N. menthoides from Iran. Iranian Journal of Pharmaceutical Research 5: 43–46.
  • Özcan T (2019) Micromorphological comparison of Nepeta viscida, N. nuda subsp. nuda and their putative hybrids N. × tmolea. Journal of Institute of Science and Technology 21: 30–42.
  • Pojarkova AI (1954) Nepeta L. In: Shishkin BK (Ed.) Flora of The U. S.S.R., Vol. 20. Academy Science of the U.S.S.R., Moskva-Leningrad, 191–293.
  • Shaw J, Lickey EB, Schilling EE, Small RL (2007) Comparison of whole chloroplast genome sequences to choose noncoding regions for phylogenetic studies in angiosperms: The tortoise and the hare III. American Journal of Botany 94(3): 275–288. https://doi.org/10.3732/ajb.94.3.275
  • Stanford AM, Harden R, Parks CR (2000) Phylogeny and biogeography of Juglans (Juglandaceae) based on matK and ITS sequence data. American Journal of Botany 87(6): 872–882. https://doi.org/10.2307/2656895
  • Swofford DL (2003) PAUP*. Phylogenetic analysis using parsimony (* and other methods). Version 4. Sinauer Associates, Sunderland.
  • Szczecińska M, Łazarski G, Bilska K, Sawicki J (2017) The complete plastid genome and nuclear genome markers provide molecular evidence for the hybrid origin of Pulsatilla × hackelii Pohl. 41: 329–337.
  • Taberlet P, Gielly L, Pautou G, Bouvet J (1991) Universal primers for amplification of three noncoding regions of chloroplast DNA. Plant Molecular Biology 17(5): 1105–1109. https://doi.org/10.1007/BF00037152
  • Van Valkenburg JLCH, Schoenenberger N, van de Vossenberg BTLH, Man in’t Veld WA, Westenberg M, Boer E (2018) A natural hybrid of Impatiens, in the introduced range, demonstrated by sequence analysis of the nuclear ribosomal DNA-gene repeat. Botany Letters 166(2): 144–152. https://doi.org/10.1080/23818107.2019.1584863
  • White TJ, Bruns T, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (Eds) PCR Protocols: a guide to methods and applications. Academic Press, New York, 315–322. https://doi.org/10.1016/B978-0-12-372180-8.50042-1
  • Yarmoohammadi M, Talebi SM, Nohooji MG (2017) Infraspecific variations in essential oil and glandular trichomes in Nepeta heliotropifolia. Biodiversitas (Surakarta) 18(3): 964–970. https://doi.org/10.13057/biodiv/d180314