A new subspecies of Seseli gummiferum (Apiaceae) from Ilgaz Mountain National Park, northern Turkey

Abstract A new subspecies Seseli gummiferum Pall. ex Sm. subsp. ilgazense A.Duran, Ö.Çetin & M.Öztürk, subsp. nov. (Apiaceae) is described from Kastamonu province, Turkey. It was collected from the open Pinus sylvestris L. and Abies nordmanniana (Steven) É.Spach. mixed forest in the northern Anatolian region. An endemic apparently confined to the Ilgaz Mountain National Park, the new taxon is closely related to Seseli gummiferum subsp. gummiferum. Diagnostic morphological characters for closely similar taxa are discussed, and a key to the subspecies of Seseli gummiferum is presented. ITS (Internal Transcribed Spacer) region of the nuclear ribozomal DNA of closely related Seseli L. taxa and Pimpinella is used to constract phylogenetic tree by using BioEdit and Seaview Programme.


Introduction
Th e Apiaceae comprise approximately 450 genera and 3700 species worldwide (Pimenov and Leonov 1993). However, the distribution of species among the genera vary, with almost half of the genera monotypic and 26% consisting of only two or three species. Sixty percent of the species in the family assign to just a few genera, which genera encompass over 20 species have been noted as polyphyletic (Spalik et al. 2004). Asian countries with the greatest biodiversity for the Apiaceae include China, Asian Turkey, Iran, Asian Russia, and Kazakhstan, with the most species given for the Chinese fl ora (677 species in 108 genera) (Pimenov and Leonov 2004). Turkey, with a considerably smaller geographic area, is second only to China in its diversity for the Apiaceae, with 450 species in 109 genera. Th ere are four endemic genera in Turkey, with 140 species among 42 genera. Th is suggests that the Asiatic region in Turkey has the highest known species-level diversity for the Apiaceae in Asia, if not in the world (Pimenov and Leonov 2004).
Seseli L. is one of the largest genera in the Apiaceae with 125 to 140 taxa ascribed to the genus worldwide. Represented by both intraspecifi c and interspecifi c diversity, Seseli is distributed in Europe, Asia, Africa, North America and Australia (Pimenov and Leonov 2004). Th e fi rst revision of Seseli in Turkey was made by Hedge and Lamond (1972), who recognized 10 infrageneric taxa. Seseli gummiferum subsp. gummiferum was reported as a new record from Turkey (Duman 2000). After that Seseli ramosissimum replaced with Seseli hartvigiii by Parolly (Parolly and Nordt 2001). Latest revision of Seseli in Turkey was made by Doğan Güner and Duman (2013). So the total number of these taxa is 13 now.

Material and methods
In 2008, during a fi eld trip in the Black Sea region of Turkey, an unusual specimen of Seseli was collected by the authors. Study of the descriptions in Hedge and Lamond (1972), Davis et al. (1988), Duman (2000), Ball (1968), Rechinger (1987), Parolly and Nordt (2001), Shishkin (1950), Özhatay et al. (2009), Doğan Güner and Duman (2013) as well as comparison with herbarium material in GAZI, HUB, KNYA and ANK revealed that the specimens indeed represented a new taxon. In particular, the new taxon was compared with the closely similar taxa Seseli gummiferum Pall. ex Sm. subsp. gummiferum and S. corymbosyum Boiss. & Heldr. In the morphological description below, each numerical value is the average of ten measurements from diff erent specimens. Th e abbreviations of the authors of plant names were checked from Brummitt and Powell (1992).
DNA isolation: Total DNA was obtained from 50-75 mg leaf and fruit from six diff erent individuals. DNAs are isolated with CTAB method and after concentrations were determined by Nanodrop. Sample DNAs were diluted 25 ng/μl. Stok DNAs were kept at -86 °C.
Distribution and IUCN red list category. Th e new subspecies is known only from the type locality, with specimens collected only from Ilgaz Mountain National Park (Kastamonu province) in Turkey, where the species seems to be very rare. Th is area is ca. 1.5 km 2 , and mature individuals of the type population number approximately 125. Th e location is very close to the road side and near forest management. Th e population is going to be negatively aff ected from cars, trucks and people in the future. Th e habitat of this subspecies is clearly under threat of destruction, and therefore, the taxon should be considered Critically Endangered (

Discussion and conclusion. Turkey is the most complex country in the Middle
East with regard to geographic structure and landforms. It's comprised of comparatively narrow and long, variously oriented mountain chains, separated by deep valleys and also high-and medium-elevational plateaus. Th e geological composition and physical direction, exposure and altitude of these mountains are here largely infl uential not only upon the diversity of vegetation, but also on the richness of the fl ora (Zohary 1973). Ilgaz Mountain, which is situated in a transitional zone in central and North of Anatolia and is generally composed of serpentine, schist and volcanic rocks. Th e mountain is orogenically interesting, with the quite active north Anatolian fault found along the southern slopes of Ilgaz Mountain (Kuter 2008). One of the more important reasons for protecting the Ilgaz Mountain is the richness and endemism of its fl ora. Approximately 100 endemic plants occur within the boundaries of the National Park and the type localities of 19 endemic taxa are found on Ilgaz Mountain. Delphinium ilgazense   (Davis 1965-1985, Davis et al. 1988, Duman 2000, Duran et al. 2008. Seseli gummiferum subsp. ilgazense is closely related to two other subspecies found in Turkey. S. gummiferum subsp. gummiferum is distributed in Crimea, Central Anatolia (Shishkin 1950, Ball 1968, Duman 2000. Th e new subspecies diff ers from S. gummiferum subsp. gummiferum, based on its glabrous fruits (not with indument), fewer central umbels, with 13 to 21 rays (not 25 to 30), fewer lateral umbels, with seven to 13 rays (not 15 to 20), as well as the bracteoles 15 to 20 (not 11 to 16) (Hedge andLamond 1972, Duman 2000).
Seseli gummiferum subsp. ilgazense also diff ers from S. gummiferum subsp. crithmifolium (DC.) P.H.Davis, which is distributed in west and east Crete, Folegandros, Sikinos, Amargos, Karpathos, Saria and neigbouring islands in Aegean Sea. Th e new taxon is not so broadly distributed, endemic and found only in northern Anatolia (Ilgaz Mountain). Seseli gummiferum subsp. crithmifolium principally diff ers from subsp. ilgazense by its puberulent fruits, the central umbels with 20-45 rays, and the oblong leaf segments (6-) 10-30 × 2-5 mm (Ball 1968, Hedge andLamond 1972).  (1672), Plantarum umbelliferarum, fruit morphology and anatomy have been regarded as essential to the taxonomy of Apiaceae (Drude 1898, Constance 1971, Spalik et al. 2001. Details of the fruits have been traditionally viewed as rich sources of taxonomic characters, exhibiting some, but not excessive variation in features such as fruit shape, the degree and direction of mericarp compression, modifi cations of the pericarp ribs (e.g. wings or spines), and the shape of mericarp commissural faces. Th us, most traditional classifi cations of Apiaceae have relied almost exclusively on fruit characters (Plunkett andDownie 1999, Pimenov et al. 2004). Seseli gummiferum subsp. ilgazense has some distinctive characteristics in terms of carpological features. Mericarps of Seseli gummiferum subsp. ilgazense have fi ve large vascular bundles situated beneath the each rib. Large vittae present in mesocarp layer adjacent to the endocarp. Th ere are also two large vittae in the commissure. Diff ering from Seseli gummiferum subsp. gummiferum, the new subspecies does not have short secretory ducts around vascular bundles. In addition, the vittae around the endocarp are always large and elliptical. Th e endosperm is round shaped. Commissure width is approximately equal to mericarp width.

Key to closely related
Diagnostic characters of Seseli gummiferum subsp. ilgazense with the three related taxa are provided in Table 1.
Five Seseli taxa and Pimpinella were evaluated in the phylogenetic analysis. PCR amplifi cation with ITS 4/ITS 5 primers generated bands ranging from 595 to 665 bp. Alignment of the ITS sequences was done using Bioedit. Neighbour-Joining (NJ) tree were constructed using Seaview programme ( Figure 6). According to NJ analyses, the taxa of Pimpinella placed in fi rst clade. Th is species was used as outgroup. Th e second clade includes Seseli libanotis, which is found in Section Libanotis. Seseli libanotis is separated from S. gummiferum and S. petraeum by having highly wide leaf segment. Th e second clade incudes Seseli petraeum, S. corymbosum, S. gummiferum in sect. Seseli. Seseli petraeum is close to Seseli gummiferum. It mainly diff ers from S. gummiferum because it has free bracteol from base and main umbel shorter than lateral umbels. Seseli corymbosum (Boiss. & Heldr.) P.H.Davis which only occurs in South Anatolia, is readily distinguished from S. gummiferum, by its solitary stem branching above, bracts either lacking or one below the central umbel, more numerous bracteoles, 19 to 23, larger central umbels with 30 to 70 rays and the lateral umbels with 13 to 47 rays, and fi nally by the pubescent petals and fruits (Hedge and Lamond 1972). Although Seseli gummiferum subsp. ilgazense is closely related to S. gummiferum subsp. gummiferum, this taxa is treated as diff erent subspecies.