Chemical and genetic diversity of two Mediterranean subspecies of Teucrium polium L

• Published in: Phytochemistry (Oxford) Vol. 83; no. 83; pp. 51 - 62
• Main Authors: Djabou, Nassim, Muselli, Alain, Allali, Hocine, Dib, Mohammed El Amine, Tabti, Boufeldja, Varesi, Laurent, Costa, Jean
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2012; Elsevier
• Subjects: chemical analysis; Chemical and genetic diversity; chemical composition; Chemical Sciences; Chloroplast and ribosomal nuclear markers; chloroplasts; color; DNA, Chloroplast - genetics; DNA, Ribosomal - genetics; Environmental parameters; Essential oil; essential oils; flowers; fractionation; France; gas chromatography; genetic background; genetic markers; Genetic Markers - genetics; genetic variation; Genetic Variation - genetics; internal transcribed spacers; mass spectrometry; monoterpenoids; oils; Oils, Volatile - chemistry; Organic chemistry; phylogeny; Polymorphism, Genetic - genetics; sesquiterpenoids; soil pH; Species Specificity; statistical analysis; Teucrium; Teucrium - chemistry; Teucrium - genetics; Teucrium polium; Teucrium polium L. subsp. capitatum; Teucrium polium L. subsp. polium; Corsica; Algeria; France; Chemical and genetic diversity; Essential oil; Teucrium polium L. subsp. polium; Chloroplast and ribosomal nuclear markers; Teucrium polium L. subsp. capitatum; Environmental parameters; Teucrium polium L. subsp. Polium; Teucrium polium L. subsp. Capitatum
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2012.05.019

Owing to the morphological variations of Teucrium polium, the chemical and genetic diversity of two Mediterranean subspecies T. polium subsp. polium from Algeria and T. polium subsp. capitatum from Corsica were investigated. [Display omitted] ► Investigation of chemical and genetic diversity of Corsican T. polium ssp. capitatum. ► Investigation of chemical and genetic diversity of Algerian T. polium ssp. polium. ► Study of chemical composition of essential oils using GC and GC/MS after column chromatography. ► Study of plant genetic structure using two chlororoplast markers and ribosomal nuclear markers. ► Chemical and genetic correlation. Chemical and genetic diversity of Teucrium polium L. subsp. polium from western Algeria and T. polium L. subsp. capitatum from Corsica were investigated. Diversity within and among the two populations of subspecies was assessed according to the chemical composition of their essential oils and the genetic diversity. Chemical analysis was performed using a combination of capillary GC-RI and GC/MS after fractionation using column chromatography. Genetic structures were mapped using three polymorphic genetic markers: two chloroplast markers (RPL32-TRNL and TRNL-F) and ribosomal nuclear markers (ITS region). The statistical analysis showed that both subspecies were clearly distinguished by these chemical and genetic markers. The oil chemical compositions differed qualitatively and quantitatively between the subspecies. Both collective oils were dominated by hydrocarbon compounds however the Algerian sample oils exhibited higher amounts of hydrocarbon sesquiterpenes than those of Corsica (31.2g/100g vs. 4.4g/100g) while the latter displayed higher amounts of hydrocarbon monoterpenes than the first (59.3g/100g vs. 34.3g/100g). Neighbor-joining, Maximum likelihood and Bayesian trees constructed from chloroplast markers and nuclear ITS region sequences showed the existence of two groups associated with taxonomic and chemical characteristics. The study indicated that variation in the essential oil composition within subspecies depends on genetic background. The samples of subsp. capitatum from Corsica are a homogeneous group, in contrast to samples of subsp. polium from Algeria which were clustered in two groups. Chemical and genetic diversity of Algerian populations could be explained by geographical isolation of the populations. In addition, the morphological polymorphism observed throughout the colour of flowers could be explained by environmental parameters as well as the soil pH.