1126 Chem. Biodiversity 2016, 13, 1126 – 1139 FULL PAPER Chemical Polymorphism of Origanum compactum Grown in All Natural Habitats in Morocco by Kaoutar Aboukhalid*a)b), Abdeslam Lamirib), Monika Agacka-Mołdochc), Teresa Doroszewskac), Ahmed Douaikd), Mohamed Bakhaa)e), Joseph Casanovaf), Felix Tomif), Nathalie Machong), and Chaouki Al Faiza) a) Institut National de la Recherche Agronomique, UR Plantes Aromatiques et Medicinales, INRA, CRRA-Rabat, PB 6570, 10101 Rabat, Morocco (phone: +212661265485, e-mail: [email protected]) b) Laboratoire de Chimie Appliquee et Environnement, Faculte des Sciences et Techniques, Universite Hassan I, BP 577, 26000 Settat, Morocco c) Institute of Soil Science and Plant Cultivation, State Research Institute, ul. Czartoryskich 8, PL-24-100 Puławy d) Institut national de la Recherche Agronomique, UR Environnement et Conservation des Ressources Naturelles, INRA, CRRA-Rabat, PB 6570, 10101 Rabat, Morocco e) Laboratoire de Biologie et Sante, Faculte des sciences, Universite Abdelmalek Essaadi,^ BP 2121, 93002 Tetouan, Morocco f) UMR 6134 SPE, Equipe Chimie et Biomasse, Universite de Corse-CNRS, Route des Sanguinaires, FR-20000 Ajaccio g) UMR 7204 CESCO, Departement d’Ecologie et gestion de la Biodiversite, Museum National d’Histoire Naturelle, 55 rue Buffon, FR-75005 Paris Origanum compactum L. (Lamiaceae) is one of the most important medicinal species in term of ethnobotany in Morocco. It is considered as a very threatened species as it is heavily exploited. Its domestication remains the most efficient way to safeguard it for future generations. For this purpose, wide evaluation of the existing variability in all over the Moroccan territory is required. The essential oils of 527 individual plants belonging to 88 populations collected from the whole distribution area of the species in Morocco were analyzed by GC/MS. The dominant constituents were carvacrol (0 – 96.3%), thymol (0 – 80.7%), p-cymene (0.2 – 58.6%), c-terpinene (0 – 35.2%), carvacryl methyl ether (0 – 36.2%), and a-terpineol (0 – 25.8%). While in the Middle Atlas region and the Central Morocco mainly carvacrol type samples were found, much higher chemotypic diversity was encountered within samples from the north part of Morocco (occidental and central Rif regions). The high chemical polymorphism of plants offers a wide range for selection of valuable chemotypes, as a part of breeding and domestication programs of this threatened species. Keywords: Origanum compactum, Essential oils, Chemical variability, Morocco. endemic to Morocco and southern Spain [2]. O. com- Introduction pactum BENTH. is the most widespread species in Mor- The genus Origanum is a taxonomically complex group occo, extending from the Middle Atlas region delimited of aromatic plants that are used all over the world for by Beni mellal, Azrou, Khenifra, and Oulmes up to the their aromatic and medicinal properties and as a culinary occidental and central Rif region, including the provinces herb [1]. According to Ietswaart’s classification [2], the of Tangier-Tetouan, Chefchaouen, Taounate, and Ouaz- genus Origanum has been divided into 38 species, 6 sub- zane [4][5]. O. compactum BENTH., known locally as species, and 17 hybrids, arranged in three groups ‘Zaatar’,^ constitutes one of the most appreciated aromatic and 10 sections. The genus Origanum has a local distri- herbs, widely used in Moroccan folk medicine in the form bution mostly around the Mediterranean basin, and it is of infusions and decoctions to threat broncopulmonary, characterized by a large morphological and chemical gastric acidity, gastrointestinal diseases, and numerous diversity [3]. infections [6]. Due to its pleasant flavor and spicy fra- In Morocco, the genus Origanum is represented by grance, O. compactum is the aromatic ingredient of five taxa, three of which, O. elongatum (BONNET)EMB & choice for flavoring some traditional dishes (barley soup, MAIRE, O. grosii PAU &FONT QUER, and O. frontqueri couscous, etc.). PAU are endemic to the central Rif region. O. vulgare Steam distillation of aerial parts of O. compactum subsp. virens (HOFFM.etLINK)IETSWAART is also common BENTH. produces an essential oil (EO), which is appre- to the Iberian Peninsula, while O. compactum BENTH.is ciated for its aromatic and medicinal properties: © 2016 Wiley-VHCA AG, Zurich€ DOI: 10.1002/cbdv.201500511 Chem. Biodiversity 2016, 13, 1126 – 1139 1127 antifungal [7 – 9], antibacterial [10][11], and antioxidant plant. Nevertheless, the domestication of wild medicinal effects [12]. Previous studies on Moroccan O. com- species requires a good understanding of the chemical pactum BENTH. EOs revealed a wide chemical diversity. and genetic diversity within the species. Although vari- Compositions were dominated either by carvacrol or by ous studies have been carried out in order to charac- thymol. Mixed types, combining both thymol and terize Moroccan O. compactum BENTH. EOs, these carvacrol, and types containing a high level of precur- studies were restricted to a limited number of samples. sors, c-terpinene and p-cymene, have also been re- Moreover, these studies did not cover the entire area ported [13 – 15]. The various compositions have about wild-growing O. compactum BENTH. where this been summarized in a previous paper that described plant still subsists, and only few studies specified the also the chemical variability observed on 36 oil samples geographical origin of samples. Furthermore, only the isolated from plants harvested in three Moroccan EO composition of mixed plant samples was reported provinces: Chefchaouen, Larache, and Tetouan [4]. and no study to date has been undertaken at intrapop- Two-thirds of the samples exhibited carvacrol as major ulation level. For instance, most Origanum species have component. cross-pollinated reproductive system [15], which can Nowadays, O. compactum BENTH. is considered as a lead to a high level of genetic polymorphism within threatened species due to a dramatic population decline populations. This variation may eventually influence the caused by various factors: overexploitation, drought, genetic control of accumulation of specific compounds overgrazing, combined with unsustainable and destruc- among the secondary metabolites [16]. In this paper, tive methods of harvesting, through up-rooting in the we report an analysis of the EO composition of wild, and collecting essentially during the flowering per- O. compactum BENTH. individual plants distributed all iod, before seed set. Since the decline of natural popu- over the Moroccan territory. This is the first report of lations, an urgent attempt to set up a domestication a deep study on native populations of O. compactum program should be initiated to ensure the conservation BENTH. Such information would be fundamental to pro- and a sustainable utilization of this valuable medicinal mote a domestication program of the species at Fig. 1. Geographical distribution of the 88 Origanum compactum accessions (noted A in Table 1) sampled from the 12 regions. The map was generated using ArcGIS Ver. 10.1. © 2016 Wiley-VHCA AG, Zurich€ www.cb.wiley.com 1128 Chem. Biodiversity 2016, 13, 1126 – 1139 Table 1. Origin, accession number, sampling locations, altitude, climate (the extraction of bioclimatic parameters was conducted using ArcGIS 10.1 software), and essential-oil yield of each Origanum compactum population studied Region Accession no. Collection site Samples No. Altitude [m] Climate EO Yield [%] Tangier-Tetouan A1 Ain Lahcen 1 – 5 200 Humid 0.82 A2 Khmiss Anjra 6 – 7 197 Humid 0.94 A3 Khmiss Anjra 8 – 15 224 Humid 1.10 A4 Melloussa 16 – 23 391 Humid 0.88 Sidi Kacem A5 Col Zeggota 24 – 29 560 Semiarid 2.67 A6 Tnine Srafeh 30 – 35 206 Semiarid 2.28 Benslimane A7 Bouznika toward Benslimane 36 208 Semiarid 2.12 A8 Krama forest 37 – 41 233 Semiarid 1.81 A9 Benslimane forest 42 – 44 224 Subhumid 2.34 A10 Oued Cherrat 45 – 47 252 Semiarid 1.54 A11 Ain dakhla 48 – 54 223 Subhumid 2.08 A12 Khatouat 55 248 Semiarid 2.61 A13 Benslimane toward Sidi Yahya Zaer 56 – 59 382 Semiarid 1.88 A14 Benslimane toward Rommani 60 – 65 223 Semiarid 2.16 A15 Benslimane toward Rommani 66 – 73 371 Semiarid 2.09 Taounate A16 Ouartzagh 74 – 75 303 Subhumid 2.22 A17 Oudka 76 – 80 1076 Humid 1.63 A18 Tabouda 81 – 88 438 Humid 1.42 A19 Kissane 89 – 95 605 Subhumid 1.92 A20 Sidi Mokhfi 96 – 106 432 Humid 1.61 A21 Zrizer 107 352 Humid 1.86 A22 Timezgana 108 – 112 297 Humid 1.94 A23 Galaz 113 – 116 369 Subhumid 1.79 A24 Ghafsai 117 – 119 397 Humid 1.43 A25 Beni zeroual 120 – 121 667 Subhumid 1.64 A26 Beni zeroual 122 – 125 220 Humid 1.89 A27 Bibane 126 – 130 524 Humid 1.58 A28 Tafrant 131 – 135 373 Subhumid 1.91 Chefchaouen A29 Talassemtane 136 – 142 881 Humid 0.89 A30 Akchour 143 – 150 307 Humid 0.95 A31 Talambote 151 – 153 399 Humid 1.34 A32 Akchour 154 – 160 957 Humid 1.23 A33 Jbel Meggou 161 – 165 845 Humid 0.84 A34 Jbel Tissouka 166 – 171 831 Perhumid 0.91 A35 Beni bouhlou 172 – 173 891 Humid 1.16 A36 Assifane 174 – 180 601 Humid 0.96 A37 Beni Ahmed 181 – 185 426 Humid 1.68 Ouazzane A38 Ain beida 186 – 190 344 Humid 2.12 A39 Brikcha 191 – 193 235 Subhumid 1.96 A40 Brikcha 194 – 197 307 Subhumid 1.42 A41 Oued loukouss 198 – 203 126 Humid 1.78 A42 Mokrisset 204 – 210 498 Subhumid 1.26 A43 Mokrisset 211 – 217 340 Humid 1.64 A44 Zoumi 218 – 223 244 Subhumid 0.93 A45 Zoumi 224 – 230 330 Subhumid 1.79 A46 Kalaat Bouqorra 231 – 234 150 Humid 2.43 A47 Souk el had 235 – 241 173 Humid 1.45 A48 Ouazzane 242 – 247 593 Humid 1.89 A49 Mokrisset 248 – 253 589 Humid 1.58 A50 Zoumi 254 – 258 256 Subhumid 1.99 A51 Jabriyine 259 – 262 252 Subhumid 1.22 A52 Brikcha 263 – 267 188 Subhumid 1.63 A53 Asjen 268 – 272 140 Subhumid 1.28 A54 Asjen 273 – 278 273 Subhumid 1.92 A55 Teroual 279 – 284 322 Subhumid 0.67 A56 Zghira 285 – 290 341 Subhumid 0.86 A57 Ain dorij 291 – 296 268 Subhumid 1.94 A58 Sidi Redouane 297 – 302 220 Subhumid 1.67 A59 Sidi Redouane 303 – 307 200 Subhumid 1.56 A60 Sidi Redouane 308 – 314 181 Subhumid 1.61 A61 Mzefroun 315 – 319 242 Subhumid 1.89 www.cb.wiley.com © 2016 Wiley-VHCA AG, Zurich€ Chem.