Table 1.
Origin of studied species and populations.
Vouchers are deposited in the following herbaria. BCN: Centre de Documentació de Biodiversitat Vegetal, Universitat de Barcelona. BC: Institut Botànic de Barcelona. BEOU: University of Belgrade. SY: Sonja Siljak-Yakovlev (personal collection), Orsay.
Table 2.
DNA content and GC percentage of Reichardia species from different populations.
Table 3.
Distribution of DAPI bands after FISH experiment.
Fig 1.
Metaphase chromosome plates and interphase nuclei of Reichardia species after double target FISH with 5S (red signals) and 35S (green signals) rDNA loci, CMA (yellow signals) and DAPI staining (blue): R. dichotoma showing 5S and 35S colocalised loci at both sites of intercalary secondary constriction (arrows and arrowheads) and four terminal 35S signals (A); R. macrophylla with 4 terminal 35S signals and two intercalary and two terminal 5S signals (B); R. tingitana showing four colocalised 5S and 35S signals (C), numerous CMA+ bands in metaphase chromosomes and interphase nucleus (D), nucleus after FISH with four 35S/5S spots (E); R. gaditana with four terminal 35S (two being very intense) and two intercalary 5S signals (F); R. picroides showing two terminal sat 35S on long chromosome arms and two intercalary 5S signals on short arms (G), DAPI+ centromeric bands and DAPI negative satellites (arrows) in the same metaphase plate as FISH, better visible on black and white photograph (G’) and CMA+ satellites (arrows) corresponding to 35S and intercalary bands (arrowheads) that corresponds to 5S signals (H). Scale bar 10 μm. Idiograms of R. dichotoma (A’), R. macrophylla (B’), R. tingitana (C’), R. gaditana (F’), R. picroides (G”) showing distribution of CMA+ (yellow) and DAPI+ (blue) bands, 35S (green) and 5S (red) rDNA signals.
Table 4.
Number and distribution of CMA+ bands in diploid chromosome set.
Table 5.
Number and position of 35S and 5S rDNA loci.
Fig 2.
Hypothetical schema of overarching karyotype evolution in the genus Reichardia involving heterochromatin, rDNA and genome size changes during descending dysploidy.
Table 6.
Comparison among data concerning genome size, total length of diploid chromosome set, pollen grain dimensions and Giemsa C-bands.
Table 7.
Phylogenetic generalised least squares (PGLS) regression statistics between somatic chromosome number (2n) and other cytogenetic and pollen traits.
Fig 3.
Majority-rule consensus phylogeny of post-burn trees of Reichardia obtained through Bayesian analysis of the ITS dataset, plotted on geographic map and showing reconstruction of ancestral genome size and chromosome number.
Posterior probabilities are indicated on branches. Values in boxes represent the ancestral genome sizes and their corresponding variances. Dots on the map depict the origin of the sequenced samples. Data on the presence of Reichardia species across Mediterranean countries were retrieved from Euro+Med [7] for R. gaditana, from Blamey and Grey-Wilson [4] for R. intermedia and for R. macrophylla and R. albanica from Conti et al. [1].
Fig 4.
Karyological, cytogenetic and pollen traits plotted on the Reichardia phylogeny.
Posterior probabilities are indicated on branches.
Fig 5.
Hypothetical schema of the implication of heterochromatin in chromosomal restructuring during reduction of the basic chromosome number and decrease of DNA content.