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Taxonomic treatment of the genus Adenocarpus (Leguminosae)

The variation in the genus Adenocarpus DC. (Leguminosae) was sampled as far as possible from its complete distribution range, the Mediterranean and tropical African regions. Characters for taxonomy were obtained from morphology and phytochemistry; a DNA analysis was also undertaken. A detailed study of morphological characters was undertaken and analyzed by one-way ANOVA, discriminant analysis and Cross Tabulation with Chi square. A flavonoid and isoflavonoid survey to provide new taxonomic characters was made using high performance liquid chromatography with diode array detection and atmospheric pressure chemical ionization-mass spectrometry. For ten of these variants, 2-8 samples were examined to investigate flavonoid variation. Nineteen flavonoids belonging to five classes (flavone C- and O-glycosides, flavonol glycosides, isoflavone glycosides and flavanones) were detected. The nuclear ITS and chloroplast trnL-trnF DNA were sequenced to provide the relationships among the variants of Adenocarpus. The phylogenies obtained from both individual and the combined analyses of the data sets were congruent. A good correlation was found in that each of the molecular clades could also be characterised by a combination of flavonoids. For example, the species in clade 4, which are distributed in South and South-East Europe and tropical Africa, are characterised by the presence of flavonol O-glycosides and 5-hydroxyisoflavone O-glycosides. In contrast, flavonol O-glycosides were absent from all but one species of the other three clades, which have a mainly North Africa distribution, and these species produce flavone mono- C-glycosides and/or flavone 7-0-glycosides instead. In addition flavone 41-O-glycosides were only found in species of clade 1 and flavanones were mainly restricted to clade 3. However, the results from the morphology, phytochemistry and phylogeny provided a framework that has been used as a basis for a new classification of the genus. Twenty- four species, including a new species from the Middle Atlas of Morocco, three subspecies and one variety of the genus Adenocarpus (Leguminosae) are recognized in a new systematic account.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:553138
Date January 2011
CreatorsShkwa Essokne, Rafaa A.
PublisherUniversity of Reading
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation

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