Utility of rDNA ITS sequences in the systematics ofTeucrium sectionPolium (Lamiaceae)

“…and is the largest and most morphologically diverse section of the genus. 1,2 Teucrium capitatum, family Lamiaceae, is a Mediterranean dwarf shrub up to 45 cm tall, that grows wild in central and south-east Portugal. As in other Lamiaceae described in the literature, the aerial organs of Teucrium spp.…”

Section: Introductionmentioning

confidence: 99%

Micromorphology of trichomes and composition of essential oil of Teucrium capitatum

Antunes

Sevinate-Pinto

Barroso

et al. 2004

Flavour & Fragrance J

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The morphology and distribution of the glandular trichomes of Teucrium capitatum L., as well as the chemical composition of the essential oils, were studied. Important differences were found with regard to the major constituents of the essential oils of five populations of T. capitatum grown in Portugal. The oil isolated from one population was characterized by a high content of oxygenated monoterpenes (33.0%), isomenthone (7.7%) being the major constituent. Another oil from a population collected from the same region was dominated by monoterpene and sesquiterpene hydrocarbons (43.9% and 23.2%, respectively), α α α α α-pinene (7.7%), sabinene (11.2%) and β β β β β-pinene (10.3%) being the main compounds. The oils from the other three populations were characterized by a high content of both sesquiterpene hydrocarbons (23.0%, 32.2% and 33.2%) and oxygenated sesquiterpenes (39.7%, 23.4% and 20.4%). T-cadinol (24.1%) and α α α α α-cadinol (9.8%) were the major compounds in the oil from one population, whereas δ δ δ δ δ-cadinene (7.5% and 9.8%) and E-caryophyllene (5.4%) or α α α α α-muurolol (6.0%) were the major constituents in the other samples. The indumentum of the vegetative and reproductive ograns from the five populations of T. capitatum, observed under scanning electron microscopy, showed the same type and distribution of glandular and non-glandular trichomes. Since the ecological and edaphic features of the collecting sites were quite similar, the chemical polymorphism observed seems to be due to genetic factors.

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“…Saxifraga (0-9.4%, Vargas & al., 1999), in Teucrium sect. Polium (1-12.5%, Oualidi & al., 1999), in Antirrhinum (0-4.37%, . Interestingly, another Alsinoideae genus in the Caryophyllaceae with a EuroAustralasian disjunct distribution (Scleranthus) displays somewhat higher divergence (0-7.7%, Smissen & al., 2003).…”

Section: Discussionmentioning

confidence: 99%

Phylogenetic and phylogeographic analysis of the western Mediterranean Arenaria section Plinthine (Caryophyllaceae) based on nuclear, plastid, and morphological markers

Valcárcel

Vargas

Feliner

2006

TAXON

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Arenaria sect. Plinthine is an easily distinguishable morphologically cohesive group encompassing 14 species and five additional subspecies. To explore phylogenetic relationships and search for phylogeographic patterns in a group that is restricted to the western Mediterranean, independent and combined analyses of four datasets (morphological characters and sequences from nuclear and plastid DNA: nrITS, trnT–trnL, trnL–trnF) were conducted using Maximum Parsimony, Neighbour–Joining, Maximum Likelihood and Bayesian Inference. Monophyly of the section is supported by the data, the ITS sequences show full agreement with taxonomy for one third of the taxa, and the high number of trnL–F haplotypes found in SE Spain (7 of 11) is consistent with the fact that this region is one of the hotspots of biodiversity in the Mediterranean. However, a number of less easily interpretable results have been obtained, despite considerable ITS variation (43 parsimony informative characters within the ingroup) and a reasonable intraspecific sampling for this marker. These results are: low resolution at deep nodes of the ingroup, partial discordance between taxonomy and ITS sequences particularly for widespread taxa, and lack of congruence not only between the topologies of the plastid and nuclear trees but also between the two plastid trees. It is proposed that a combination of factors (rampant aneuploidy, polyploidy, hybridization, lineage sorting, and concerted evolution of ITS sequences) are responsible for the incongruent but not totally unexpected results.

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Utility of rDNA ITS sequences in the systematics ofTeucrium sectionPolium (Lamiaceae)

Cited by 31 publications

References 34 publications

Chemical and genetic differentiation of Corsican subspecies of Teucrium flavum L.

Chemical and genetic differentiation of Corsican subspecies of Teucrium flavum L.

Micromorphology of trichomes and composition of essential oil of Teucrium capitatum

Phylogenetic and phylogeographic analysis of the western Mediterranean Arenaria section Plinthine (Caryophyllaceae) based on nuclear, plastid, and morphological markers

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