A New Species of Sisymbrium (Brassicaceae) from Turkey: Morphological and Molecular Evidence
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Turkish Journal of Botany Turk J Bot (2015) 39: 325-333 http://journals.tubitak.gov.tr/botany/ © TÜBİTAK Research Article doi:10.3906/bot-1404-28 A new species of Sisymbrium (Brassicaceae) from Turkey: morphological and molecular evidence Birol MUTLU*, Şükrü KARAKUŞ Department of Biology, Faculty of Science and Art, İnönü University, Malatya, Turkey Received: 08.04.2014 Accepted: 05.10.2014 Published Online: 16.03.2015 Printed: 10.04.2015 Abstract: Sisymbrium malatyanum Mutlu & Karakuş is identified as a new species from Malatya Province, East Anatolia, Turkey. Morphological and molecular (entire ITS region) studies proved that this species especially resembles Sisymbrium brassiciforme, S. heteromallum, S. altissimum, S. damascenum, and S. austriacum subsp. contortum. New species and related taxa are discussed in terms of morphological and molecular differences. Epicuticular wax on the fruit surface of the new species was determined. SEM images (hairs on leaf, stem, fruit, stylus, and epicuticular wax crystalloids) and field photographs (habitat, flowering and fruiting shape of habitus, and fruit) are presented. Key words: Brassicaceae, epicuticular wax, ITS, new species, Sisymbrium 1. Introduction al., 2007). These studies have also demonstrated that The family Brassicaceae is the richest in the United States Sisymbrium consists of only about 40 species. (616 species, 148 endemic) and the second richest in Sisymbrium is one of 98 genera within the family Turkey (606 species, 39 subspecies, 18 varieties, and 226 Brassicaceae (tribe Sisymbrieae DC.) in Turkey. The genus endemics) in terms of species number (Al-Shehbaz et is represented by 10 species in Turkey (Hedge, 1965; Al- al., 2007; Al-Shehbaz, 2010; Mutlu, 2012). Forty species Shehbaz, et al., 2007; Mutlu, 2012). These species are S. belonging to the family Brassicaceae in Turkey were altissimum L., S. confertum Stev., S. elatum K.Koch, S. published as new species in the last decade (Mutlu, 2012), irio L., S. loeselii L., S. officinale (L.) Scop., S. orientate and this number has continued to increase. L., S. polyceratium L., S. runcinatum Lag. ex DC., and S. The authors collected numerous species in Malatya septulatum DC. Province between 2011 and 2013, and one of these species Five species of the genus Sisymbrium in Turkey were was published as a new species (Mutlu and Karakuş, 2012). examined in this study and one of them was identified as One of the collected samples could not be designated a new species according to morphological and molecular according to the current literature (Bush, 1939; Ball, (including ITS1, 5.8S, and ITS2) data. 1964; Hedge, 1965; Zohary, 1966; Rico, 1996; Al-Shehbaz, 2001, 2010; Khodashenas and Assadi, 2007) and it 2. Materials and methods seems to represent a new-to-science species of the genus 2.1. Plant material Sisymbrium L. (English: yellow rocket; German: Rauken; Plant materials for the new species were collected during Turkish: bülbül otu) (Figure 1). The genus is distributed mainly in the Old World, a field survey conducted in 2013 in Malatya Province in and only one species, S. linifolium Nutt., is native to Turkey. These specimens were kept in the INU herbarium. North America (Al-Shehbaz, 2006). Morphological and Three specimens (one was flowering and the other 2 extensive molecular studies identified that yellow flowers, were fruiting) of the new species and 4 different species strongly 2-lobed stigmas, often pinnately divided but never (one specimen each of S. altissimum, S. officinale, and S. auriculate or amplexicaul cauline leaves, and simple or no septulatum and 2 specimens of S. orientale) were examined. trichomes (except S. burchellii DC.) are synapomorphies 2.2. DNA amplification and sequencing for the genus (Warwick et al., 2002; Warwick and Al- DNA of the specimens was extracted from dried leaves of Shehbaz, 2003; Al-Shehbaz, 2004, 2006, 2012; Bailey et the herbarium samples. * Correspondence: [email protected] 325 MUTLU and KARAKUŞ / Turk J Bot Figure 1. Sisymbrium malatyanum sp. nov. (photographed by B Mutlu): A- habit in flowering; B- habit in fruiting; C- basal leaf and flowers; D- fruit. Total genomic DNA was extracted by the method of follows: 10X PCR buffer 4 µL, dNTP mix (10 mM) 2 µL, Warwick et al. (2002) using a modified CTAB extraction MgCl2 (25 mM) 4.0 µL, each primer (10 pmol/µL) 1 µL, method. The entire ITS region was amplified, and primers Taq polymerase (5 U/µL) 0.5 µL, sample DNA (50 ng/µL) ITS1-18S and ITS4 as described by O’Kane et al. (1996) 2.5 µL, and dH2O 10 µL. Protocol for PCR was as follows: 5 and White et al. (1990) were used. The amplification min at 95 °C, 32 cycles (94 °C for 30 s, 52 °C for 1 min, and reaction mixture (25 µL × 2) for PCR was prepared as 72 °C for 90 s), elongation at 72 °C for 7 min, and storage 326 MUTLU and KARAKUŞ / Turk J Bot at 4 °C until used. All the PCR examinations were carried 3. Results and discussion out using a Thermo Px2 Thermal Cycler. Amplification Sisymbrium malatyanum is morphologically similar to S. products were cleaned using a PCR Clean-Up Gel altissimum L. (fruiting pedicel as thick as mature fruit, Extraction Kit (Macherey-Nagel, Germany) in accordance fruiting pedicel longer than 5 mm), S. damascenum Boiss. with the manufacturer’s instructions. & Gaill. (hairy stem and fruit, fruiting pedicel longer than PCR products (25 µL) were mixed with 6X gel loading 5 mm), and S. austriacum Jacq. subsp. contortum (Cav.) buffer (5 µL) and loaded onto agarose (1.4% w/v, with 4 µL Rouy & Foucaud (siliqua longer than 20 mm, lower leaves EtBr/115 mL 1X TBE buffer) gel electrophoresis in 1X TBE deeply lobed, petal longer than 3 mm, fruiting pedicel buffer at 60 V for 120 min. DNA bands were visualized as thick as mature fruit, ovule 30–35 in each loculus). and photographed under UV light. A DNA molecular size Sisymbrium altissimum is cosmopolitan species growing marker (50-bp marker, BioLabs) was used. in North America, Asia, Europe, North Africa, and East The PCR products were sequenced using a Sanger Australia. However, while S austriacum subsp. contortum automated DNA sequencer (Applied Biosystems) at İontek grows only in Spain and Portugal, S. damascenum grows Research and Biotechnology Company (İontek Corp., only in Syria and Jordan (Ball, 1964; Hedge, 1965; Zohary, İstanbul, Turkey). All DNA sequences in this study were 1966; Rico, 1996; Al-Shehbaz, 2001, 2010; Khodashenas deposited in GenBank, and Table 1 gives the accession and Assadi, 2007). numbers of these sequences. Figure 2 illustrates results of MP and BI analysis as a 2.3. Sequence alignment and phylogenetic analyses comparative tree. Bootstrap values (in the MP tree) and DNA sequences of 24 species (2 outgroups) were obtained posterior probabilities (in the BI tree) are given above for comparison from GenBank (http://www.ncbi.nlm. branches at ≥50% for the supported clade. Tree length (L) nih.gov/genbank/). Two species (Capsella bursa-pastoris was 404, consistency index (CI) was 0.65, and retention (L.) Medik. and Neotorularia torulosa (Desf.) Hedge index (RI) was 0.86 for the parsimony tree. MP and & J.Léonard) were selected as outgroups. Table 1 lists BI analysis based on molecular data showed that new GenBank accession information for the sequences of species is more closely related to S. brassiciforme and S. compared and studied species. heteromallum. As seen from Figure 2, the new species The entire ITS region (ITS-1, 5.8S, and ITS2) sequences is most close to S. brassiciforme. Schultz placed these 2 were automatically aligned by CLUSTALW (Thompson et species in the section of Grypolobus O.E.Schulz and the al., 1994). species in this section are distributed in Central Asia. Maximum parsimony (MP) analyses were performed Sisymbrium brassiciforme is a more common species in using PAUP 4.0b10 with heuristic search strategy according to the tree bisection and reconnection branch-swapping West Asia compared to S. heteromallum. Furthermore, algorithm. The MULTREES option and ACCTRAN the distribution area of S. brassiciforme is the closest to optimization were activated (Swofford, 2003). Gaps in the Turkey (Khodashenas and Assadi, 2007). Distinguishing alignment were treated as missing data. All characters were characters of the section are petiolate leaves, simple treated as unordered and equally weighted. Limitations of trichomes, ebracteate racemes, slender fruiting pedicel, computer memory required constraining the maximum yellow petal, entire or 2-lobed stigma, 3-veined fruit valve, number of trees to 1000 per replicate and limiting the uniseriate seed, and incumbent cotyledons. Some of these maximum tree number to 40,000. characters are shown in the new species (Figures 3A–3D). Bayesian inference (BI) analysis, which is an alternative SEM studies conducted on the epidermal surface of phylogenetic method, was performed using MrBayes Sisymbrium malatyanum showed that the epicuticular 3.2.2 (Huelsenbeck and Ronquist, 2001; Ronquist and surface has wax crystalloids, observed especially on the Huelsenbeck, 2003). The Markov chain Monte Carlo fruit surface (Figures 3E and 3F). These crystalloids are flat method was used for 3 million generations. The settings and connected to the epicuticular surface by their narrow were as follows: 2 independent runs, with nucmodel = 4 by side. These epicuticular wax crystalloids were named as 4, Nst = 6, rates = invgamma, samplefreq = 1000, 4 chains “platelets” by Barthlott et al. (1998). Epicuticular waxes = 1 cold and 3 hot, and sump burnin= 450 samples. were observed on some Brassicaceae species, especially on Results of MP and BI analyses were drawn as trees with Arabidopsis thaliana (L.) Heynh. (Broun et al. 2004) and TREEVIEW (Page, 1996). Brassica spp. (Baker, 1974; Ni et al., 2014). This epicuticular 2.4. SEM studies wax on the epidermal surface was first identified in the Before the SEM studies were carried out, samples were coated species of the genus Sisymbrium.