Subgeneric delimitation of the plant genus Phyllanthus (Phyllanthaceae)

Over two centuries of taxonomic studies on the species rich genus Phyllanthus have culminated in a broadand complicated classification with many subgenera and (sub)sections. Past taxonomic work has only focused on local revisions, mostly because of the size of the genus. In this study we aim to summarize most of the taxonomic work in a list containing the infrageneric delimitations of Phyllanthus. This work will serve as a reference, placing most currently recognized species in subgenera and if possible, in sections for further study. Here we recognize 880 species of Phyllanthus, classified in 18 subgenera, 70 sections and 14 subsections. A few taxonomic changes are necessary to reconcile published phylogenetic data with the current classification. Subsections Callidisci and Odontadenii are raised to sectional rank, while section Eleutherogynium and section Physoglochidion are reduced to subsections and P. oxycarpus is transferred to the genus Glochidion. A provisional key for the subgeneric classification of Phyllanthus is provided.Naturali

Molecular phylogenetics of Phyllanthus sensu lato (Phyllanthaceae): Towards coherent monophyletic taxa

The genus Phyllanthus is paraphyletic as currently circumscribed, with the genera Breynia, Glochidion and Synostemon nested within it. A phylogeny based on nuclear (ITS, PHYC) and chloroplast (matK, accD-psaI, trnS-trnG) markers is presented, including 18/18 subgenera and 53/70 sections. Differences in habit, branching type, floral and fruit characters are discussed, and we find indications for shifts in pollination and dispersal strategies possibly underlying the convergent evolution of these characters in multiple clades. Several taxonomic issues were found in the subgeneric classification of Phyllanthus that will require new transfers and rank changes. Phyllanthus subg. Anesonemoides, subg. Conami, subg. Emblica, subg. Gomphidium, subg. Kirganelia and subg. Phyllanthus are polyphyletic, and several sections appear to be paraphyletic (e.g., P. sect. Anisonema, sect. Emblicastrum, sect. Pseudoactephila, sect. Swartziani, and sect. Xylophylla); P. subg. Phyllanthodendron is furthermore paraphyletic with the genus Glochidion nested within. To create a classification of tribe Phyllantheae that comprises exclusively monophyletic taxa, it is necessary to treat several clades at the same taxonomic rank as the genera Breynia, Glochidion and Synostemon. Since combining all genera would lead to one giant heterogeneous genus that is difficult to define, we recommend dividing Phyllanthus into several monophyletic genera, which have previously been recognized and often possess diagnostic (combinations of) morphological characters. This new classification is forthcoming.Plant sciencesNaturali

A revised phylogenetic classification of tribe Phyllantheae (Phyllanthaceae)

The majority of tribe Phyllantheae (Phyllanthaceae) is currently placed in the paraphyletic genus Phyllanthus and discussions have persisted on how to resolve this issue. Here, we split Phyllanthus into ten monophyletic genera, which are all reinstatements of former genera, but with changes made to the circumscription and constituent species of each group. The genera Breynia, Glochidion and Synostemon were recently found to be nested within Phyllanthus and discussions ensued whether or not to subsume everything into Phyllanthus s.l. Instead of combining all these genera, we here implement the solution of splitting Phyllanthus into strictly monophyletic genera to ensure that the classification is consistent with the latest phylogenetic results. The new classification is based on a phylogenetic framework combined with differences in habit, branching type, floral, fruit and pollen morphology. With this new division of the genus Phyllanthus, tribe Phyllantheae will consist of the following 18 genera: Breynia, Cathetus, Cicca, Dendrophyllanthus, Emblica, Flueggea, Glochidion, Heterosavia, Kirganelia, Lingelsheimia, Lysiandra, Margaritaria, Moeroris, Nellica, Nymphanthus, Phyllanthus, Plagiocladus and Synostemon. As a result of the reinstated genera, five new names for illegitimate combinations or previous overlooked nomenclatural anomalies and 645 new combinations are proposed. Several keys are provided to distinguish the reinstated genera. Full species lists are given for the reinstated genera treated here except for Breynia, Synostemon and Glochidion.Plant sciencesNaturali

Subgeneric delimitation of the plant genus Phyllanthus (Phyllanthaceae)

Over two centuries of taxonomic studies on the species rich genus Phyllanthus have culminated in a broad and complicated classification with many subgenera and (sub)sections. Past taxonomic work has only focused on local revisions, mostly because of the size of the genus. In this study we aim to summarize most of the taxonomic work in a list containing the infrageneric delimitations of Phyllanthus. This work will serve as a reference, placing most currently recognized species in subgenera and if possible, in sections for further study. Here we recognize 880 species of Phyllanthus, classified in 18 subgenera, 70 sections and 14 subsections. A few taxonomic changes are necessary to reconcile published phylogenetic data with the current classification. Subsections Callidisci and Odontadenii are raised to sectional rank, while section Eleutherogynium and section Physoglochidion are reduced to subsections and P. oxycarpus is transferred to the genus Glochidion. A provisional key for the subgeneric classification of Phyllanthus is provided

Phylogenetic reconstruction prompts taxonomic changes in Sauropus, Synostemon and Breynia (Phyllanthaceae tribe Phyllantheae)

Previous molecular phylogenetic studies indicated expansion of Breynia with inclusion of Sauropus s.str. (excluding Synostemon). The present study adds qualitative and quantitative morphological characters to molecular data to find more resolution and/or higher support for the subgroups within Breynia s.lat. However, the results show that combined molecular and morphological characters provide limited synergy. Morphology confirms and makes the infrageneric groups recognisable within Breynia s.lat. The status of the Sauropus androgynus complex is discussed. Nomenclatural changes of Sauropus species to Breynia are formalised. The genus Synostemon is reinstated

Genetic diversity of the greater yam (Dioscorea alata L.) and relatedness to D. nummularia Lam. and D. transversa Br. as revealed with AFLP markers

UMR DAPInternational audienceAmplified fragment length polymorphism markers were used to assess the genetic relatedness between Dioscorea alata and nine other edible Dioscorea. These species include D. abyssinica Hoch., D. bulbifera L., D. cayenensis-rotundata Lamk. et Poir., D. esculenta Burk., D. nummularia Lam., D. pentaphylla L., D. persimilis Prain. et Burk., D. transversa Br. and D. trifida L. Four successive studies were conducted with emphasis on the genetic relationship within D. alata and among species of the Enantiophyllum section from Vanuatu. Study 1 was carried out to select a set of polymorphic primer pairs using 11 combinations and eight species belonging to five distinct sections. The four most polymorphic primer pairs were used in study 2 among six species of the Enantiophyllum section. Study 3 focussed mainly on the genetic relationship among 83 accessions of D. alata, mostly from Vanuatu (78 acc.) but also from Benin, Guadeloupe, New Caledonia and Vietnam. The ploidy level of 53 accessions was determined and results indicated the presence of tetraploid, hexaploid and octoploid cultivars. Study 4, included 35 accessions of D. alata, D. nummularia and D. transversa and was conducted using two primer pairs to verify the taxonomical identity of thecultivars ‘langlang’, ‘maro’ and ‘netsar’ from Vanuatu. The overall results indicated that each accession can be fingerprinted uniquely with AFLP. D. alata is an heterogeneous species which shares a common genetic background with D. nummularia and ‘langlang’, ‘maro’ and ‘netsar’. UPGMA cluster analysis revealed the existence of three major groups of genotypes within D. alata, each assembling accessions from distant geographical origins and different ploidy levels. The analysis also revealed that ‘langlang’, ‘maro’ and ‘netsar’ clustered together with the cultivar ‘wael’ (D. transversa) from New Caledonia. Results are discussed in the pape