International audienceCytotaxonomic investigations of the autumnflowering squills, Prospero autumnale (L.) Speta : Scilla autumnalis L., Prospero obtusifolium (Poir.) Speta :Scilla obtusifolia Poir., Barnardia numidica (Poir.) Speta : Scilla numidica Poir., and Hyacinthoides lingulata (Poir.) Rothm. : Scilla lingulata Poir. were performed in 20 populations from northern Algeria located between Tipasa and La Vieille Calle. Various chromosome numbers were found, including a new cytotype, 2n = 8, for the flora of Algeria, concerning plants identified as Prospero obtusifolium (Poir.) Speta [including P. fallax (Steinh.) Speta = S. autumnalis L. ssp. fallax (Steinh.) Batt.]. The numbers 2n = 14, 28, and 42 correspond, respectively, to diploid, tetraploid, and hexaploid levels of P. autumnale s.l. [including P. pulchellum (Munby) Speta : Scilla pulchella Munby = S. autumnalis var. pulchella (Munby) Batt.], with x = 7. The cytotypes of Barnardia numidica (Poir.) Speta with 2n = 18 and Hyacinthoides lingulata (Poir.) Rothm. with 2n = 16 chromosomes were confirmed

International audienceIntercontinental introductions are widespread in the genus Spartina, with important ecological and evolutionary consequences. The native or introduced status of Spartina species is then critical with regard to biodiversity assessment, especially for vulnerable Mediterranean coastline ecosystems. Spartina versicolor was first recorded in southern France in 1849, then successively in various places on the European and North-African Mediterranean and Atlantic coasts. This species is considered to be either a European native or an invasive species introduced from North America which has a high morphological similarity to the Atlantic American species Spartina patens. We performed extensive sampling of S. versicolor in Europe and North Africa (from natural populations and herbarium collections) and compared these samples to other European and American Spartina species (including S. patens). Chromosome counts were reported for the first time and revealed that S. versicolor is tetraploid (2n = 4x = 40). Phylogenetic analyses based on chloroplast and nuclear ribosomal DNA sequences did not reveal any molecular variation within S. versicolor. In this species, a single haplotype, that is identical to one haplotype of S. patens, was found in the four chloroplast and the nuclear ribosomal ITS regions investigated. In addition, simple sequence repeat markers were used and revealed a low level of genetic diversity within S. versicolor, suggesting that the introduction of S. versicolor occurred from a narrow genetic pool of S. patens from North Ameri

Population diversity and evolutionary relationships in the Hordeum murinum L. polyploid complex were explored in contrasted bioclimatic conditions from Algeria. A multidisciplinary approach based on morphological, cytogenetic, and molecular data was conducted on a large population sampling. Distribution of diploids (subsp. glaucum) and tetraploids (subsp. leporinum) revealed a strong correlation with a North-South aridity gradient. Most cytotypes exhibit regular meiosis with variable irregularities in some tetraploid populations. Morphological analyses indicate no differentiation among taxa but high variability correlated with bioclimatic parameters. Two and three different nuclear sequences (gene coding for an unspliced genomic protein kinase domain) were isolated in tetraploid and hexaploid cytotypes, respectively, among which one was identical with that found in the diploid subsp. glaucum. The tetraploids (subsp. leporinum and subsp. murinum) do not exhibit additivity for 5S and 45S rDNA loci comparative with the number observed in the related diploid (subsp. glaucum). The subgenomes in the tetraploid taxa could not be differentiated using genomic in situ hybridization (GISH). Results support an allotetraploid origin for subsp. leporinum and subsp. murinum that derives from the diploid subsp. glaucum and another unidentified diploid parent. The hexaploid (subsp. leporinum) has an allohexaploid origin involving the two genomes present in the allotetraploids and another unidentified third diploid progenitor.

Forty wild populations belonging to five Asparagus species including the endemic A. altissimus were sampled in an eastwest bioclimatic gradient of North Algeria. More than 250 individuals were taxonomically examined and karyologically investigated. Meiotic behavior was analyzed for each species. New chromosome numbers were consistent with the base number x = 10 for the genus Asparagus, and two cytotypes, diploid and hexaploid, were observed. Four species were found to have 2n = 20 chromosomes, highlighting the prominence of diploidy in North Africa. One polyploid with 2n = 60 is reported here as the first karyological information on the endemic A. altissimus. Karyotype parameters were established and compared for diploid species. New data provided for A. acutifolius and A. albus indicate differences in the number of submetacentric chromosomes and genome size estimated by total chromosome length. A. acutifolius is distinguished by the largest genome, the smallest being that of A. horridus. The hexaploid cytotype consists of very small metacentric chromosomes. All diploid species displayed regular meiotic behavior with mostly bivalent pairing. Abnormalities, including univalents, multivalents, laggards, and bridges, were sometimes observed in A. horridus and A. officinalis. The new cytogenetic information provided in this study is discussed in the biogeographic context of the North African flora.

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