Mobilisation de sources du XIXe siècle dans les études contemporaines de systématique des plantes cultivées

National audienc

Reconstructing pedigrees using probabilistic analysis of ISSR amplification

Data obtained from ISSR amplification may readily be extracted but only allows us to know, for each gene, if a specific allele is present or not. From this partial information we provide a probabilistic method to reconstruct the pedigree corresponding to some families of diploid cultivars. This method consists in determining for each individual what is the most likely couple of parent pair amongst all older individuals, according to some probability measure. The construction of this measure bears on the fact that the probability to observe the specific alleles in the child, given the status of the parents does not depend on the generation and is the same for each gene. This assumption is then justified from a convergence result of gene frequencies which is proved here. Our reconstruction method is applied to a family of 85 living accessions representing the common broom {\it Cytisus scoparius}.Comment: 5 figure

Floral morphology to discriminate taxa between and within Cytisus sect. Alburnoides, sect. Spartopsis and sect. Verzinum (Genisteae, Fabaceae)

Delimitation of sections is controversial within the genus Cytisus L. (Fabaceae, Genisteae). A morphological study has been conducted on 19 taxa from sections Alburnoides, Spartopsis and Verzinum to clarify their discrimination. Thirty-five quantitative and qualitative characters were recorded on a maximum of 15 dry or living flowers per taxon. Three multiple correspondence factor analyses (MCFA) were performed on a matrix based on 22 of the 35 recorded morphological characters to (1) compare the variability within and between individuals and (2) distinguish groups among the studied taxa. MCFA showed that both flowers sampled from the same plant or different individuals could represent the morphological variability of a taxon. MCFA also clustered the 19 taxa into three groups corresponding to sections Alburnoides, Spartopsis and Verzinum as defined by Cristofolini and Troia (Taxon 44:733–746, 2006). However, floral morphology has not been sufficient to discriminate taxa within sections. A key of the three studied sections based on floral characters is given

Names, collections, and molecular data of cultivated plant taxonomy

Like taxonomy of wild taxa, taxonomy of cultivated plants deals at least with three kinds of information: names, collections and molecules. However, in the case of cultivated plants, some complications occur, such as lost names of cultivated plants which have been missed from indexing by large databases. Herbaria with large sets of old cultivated material are excessively rare and a good number of cultivars has been lost due to lack of cultivation. In contrast, it is easier to establish living collections of and get molecular data from cultivated plants than wild taxa. Unraveling the history of plant selection using molecular tools is complicated as most cultivated groups are subject to artificial hybridization. Using samples from various woody angiosperm genera, we will consider some of these points to highlight specificities of the taxonomy of cultivated plant, including sparse source of information and reticulated history

Consanguinité panmictique et consanguinité systématique (Coefficients de wright et de malécot)

International audienc

Typification of names in genus Hieracium based on original herbarium material of Alexis Jordan and Alexandre Boreau

181 names of Hieracium species going back to original herbarium material of Alexis Jordan or Alexandre Boreau are lectotypified, 27 are neotypified. The study is based on herbarium specimens of the Université Catholique de Lyon (LY) and Ville d’Angers (ANG), Martrin-Donos’s herbarium at the Institut Botanique de Montpellier (MPUTarn) and Arvet-Touvet’s herbarium at the Musée d’Histoire Naturelle de Grenoble (GRM-AT). The type specimens are illustrated by photographs of the entire herbarium sheets with some detail views of flower heads and leaves. Usual nomenclatural synonyms are given for each taxon