Intra- and interspecific chromosome polymorphisms in cultivated Cichorium L. species (Asteraceae)

Abstract

Endive (Cichorium endivia L.) and chicory (C. intybus L.) both have 2n = 18, but until now, there has been no detailed karyomorphological characterization. The present work evaluated five accessions of each species using FISH with rDNA probes and fluorochrome staining with CMA and DAPI. Both species presented distinct banding patterns after fluorochrome staining: while endive had proximal CMA++/DAPI− bands in the short arms of pairs 1, 2 and 3, chicory had proximal CMA-positive bands in chromosomes 1 and 3 and interstitial in the short arm of chromosome 8. Among endive accessions, FISH procedures revealed conserved position and number of 5S and 45S rDNA sites (two and three pairs, respectively), associated with the CMA-positive bands. Notwithstanding, polymorphisms were detected within chicory accessions regarding the number and the distribution of rDNA sites in relation to the most frequent karyotype (two pairs with 45S and one with 5S rDNA). The karyological markers developed allowed karyotypic differentiation between both species, uncovering peculiarities in the number and position of rDNA sites, which suggest chromosome rearrangements, such as translocations in chicory cultivars. The interspecific and intraspecific polymorphisms observed emphasize the potential of karyomorphological evaluations, helping our understanding of the relationships and evolution of the group.

Unraveling the karyotype structure of the spurges Euphorbia hirta Linnaeus, 1753 and E. hyssopifolia Linnaeus, 1753 (Euphorbiaceae) using genome size estimation and heterochromatin differentiation

“…In addition, both species presented 5S rDNA sites associated with CMA + bands (Figure 3), as described for castor, in which there was also a chromosome pair bearing both 5S rDNA and 45S rDNA (Vasconcelos et al 2010), and other few angiosperms (e.g. Cabral et al 2006, Bernardes et al 2013). As discussed by Roa and Guerra (2015), the occurrence of 5S and 45S rDNA sites in the same chromosome (as observed for Euphorbia hyssopifolia ) has been reported in several angiosperm species, possibly as a consequence of random transpositions of both sequences.…”

Nuclear genome size and cytotype analysis inAgave parvifloraTorr. subsp.flexifloraGentry (Asparagales, Asparagaceae)

“…Species with sexual reproduction, e.g. Cichorium intybus (Bernardes et al 2013) and Lysimachia mauritiana (Kono et al 2012), also showed intraspecific variation in their karyotypes. This variation can be attributed to the plasticity of each species to adapt to different environmental situations and to increase their fecundity during asexual reproduction (Marcucci and Tornadore 2002).…”

Insights into the Sesquiterpenoid Pathway by Metabolic Profiling and De novo Transcriptome Assembly of Stem-Chicory (Cichorium intybus Cultigroup “Catalogna”)

“…The C. intybus species has a large (2n = 2x = 18; size 1405 Mbp) and complex genome (De Simone et al, 1997; Berardes et al, 2013). Culti-groups are mostly allogamous due to different mechanisms of self-incompatibility (Eenink, 1981, 1982; Varotto et al, 1995) and natural hybrids widely occur (Kiaer et al, 2009; Bai et al, 2012).…”