Chromosome numbers for the Italian flora : 2

In this contribution new chromosome numbers for Italian endemic taxa are presented. It includes 13 chromosome counts for Ornithogalum (Asparagaceae), Anthemis, Carduus, Centaurea, Cirsium, Hieracium, Taraxacum (Asteraceae), Asyneuma (Campanulaceae), Knautia (Caprifoliaceae), Gypsophila (Caryophyllaceae), Linum (Linaceae), Helleborus (Ranunculaceae).

Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Observations.Linum katiae occurs only in Calabria, restricted to a single population on the Pollino Massif (Manfriana mountain) (Peruzzi 2011).The chromosome number found is consistent with all the other existing counts reported for the Italian populations belonging to species in the Linum perenne group (Bedini et al. 2010 onwards).This species also exhibits a certain morphological affinity with L. narbonense L., in having relatively elongated styles and sepals ciliolate at the margins (Peruzzi 2011).However, the latter species shows a completely different chromosome complement, i.e., 2n = 28 (Ray 1944, Bari and Godward 1970, Löve and Kjellqvist 1974, Rogers 1980, González Zapatero et al. 1989, Yurkevich et al. 2009, Muravenko et al. 2010), so that any close relationship between L. katiae and L. narbonense can be excluded, according to our results.
Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Observations.This species is endemic to Basilicata and Calabria (Peruzzi et al. 2014), and it is typical of calcareous cliffs on the Pollino Massif.According to our results, H. portanum is tetraploid with 2n = 4x = 36, since the base chromosome number of this genus is x = 9 (Ilnicki and Szeląg 2011).Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.

L. Peruzzi
Observations.This species is restricted to southern Italy, where it occurs in Campania, Basilicata, and Calabria, whereas its presence is not confirmed in Abruzzo and Sicily (Peruzzi et al. 2014).In the past, at least three chromosome counts were attributed to A. trichocalycinum (Contandriopoulos 1966, Tzanoudakis and Kypriotakis 1987, Anchev 1993), but according to their geographical provenance they should all be referred to A. pichleri (Vis.)D.Lakušić & F.Conti (Lakušić and Conti 2004).
Therefore, chromosome number also distinguishes these two species, since Asyneuma trichocalycinum is possibly tetraploid with 2n = 4x = 64 chromosomes, while the closely related A. pichleri from the Balkans is diploid with 2n = 2x = 32.
Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Observations.This taxon is distributed in central-southern Italy, from Emilia-Romagna to Calabria (Peruzzi et al. 2014).Like the autonymic subspecies, it has 2n = 2x = 16 chromosomes, the only chromosome number found until now within this species (Bedini et al. 2010 onwards).Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.

Gypsophila arrostii
Observations.This subspecies is endemic to southern Italy (Apulia, Basilicata, Calabria, and Sicily; Peruzzi et al. 2014)   Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Observations.This taxon is restricted to Italy, where it occurs on the mountains of the Majella (Abruzzo), Pollino Massif (Basilicata) and Sila (Calabria) (Peruzzi et al. 2013).Two other counts are known for this taxon, one for Abruzzo (2n = 20; see Peruzzi et al. 2013) and one for Calabria (2n = 40; see Ehrendorfer 1975), the latter corresponding to the same chromosome number found by us and showing a tetraploid asset.Our finding further supports the conclusions by Peruzzi et al. (2013), who consider diploids and tetraploids as belonging to the same taxon.Indeed, the studied tetraploid plants are morphologically more similar to the diploids growing in Abruzzo than to tetraploids in the Sila (Calabria).Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.

Ornithogalum etruscum
Observations.Ornithogalum etruscum is distributed in northern and central Italy, with two subspecies: O. etruscum subsp.etruscum (in Liguria, Tuscany, Marche Um-  (Peruzzi et al. 2014).A careful biosystematic revision of these two taxa, involving several accessions all across their ranges, would be desirable.In addition, both names still lack typification (Peruzzi et al. 2015).
Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Observations.This species occurs only in Tuscany on the Appennino Lucchese (Arrigoni 2006).According to Kirschner et al. (2007 onwards), this taxon is included within T. sect.Taraxacum, which mostly includes diploid and triploid taxa (Richards 1969, Mogie andRichards 1983).Based on our results, T. gianninii is triploid, i.e., 2n = 3x = 24.Method.Squash preparations were made on root tips obtained from germinating seeds.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Observations.Similar to Taraxacum gianninii, T. lucense is distributed on the Appennino Lucchese, and sometimes these two species share the same sites (Arrigoni 2006).According to our count, T. lucense is also triploid with 2n = 3x = 24, the most common chromosome number found in T. sect.Erythrosperma (Richards 1969) to which T. lucense belongs.
G. Astuti, F. Roma-Marzio & L. Peruzzi Method.Squash preparations were made on root tips obtained from potted plants, originally growing in nature, cultivated at the botanical garden of Centro Ricerche Floristiche dell'Appennino.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Observations.This taxon occurs exclusively in the Abruzzo administrative region (Peruzzi et al. 2014), where it is distributed on the Majella and Morrone mountains as well as on Pizzo Intermesoli and Corno Piccolo (Gran Sasso) (Conti 1998, Conti andBartolucci 2016).This is the first chromosome count ever for this taxon, which differs from the nominal subspecies by having 2n = 36 instead of 2n = 18 chromosomes (Brullo and Pavone 1978).Hence, similar to five other subspecies of A. cretica occurring in Italy, A. cretica subsp.calabrica (Arcang.)R.Fern., A. cretica subsp.carpatica (Willd.)Grierson, A. cretica subsp.columnae (Ten.)Franzén, A. cretica subsp.messanensis (Brullo) Giardina & Raimondo, and A. cretica subsp.saxatilis (DC.)R.Fern.(Capineri 1968, Brullo et al. 1988;Selvi 2009), this taxon is probably tetraploid.This probably could be the reason for its larger size as compared to A. cretica subsp.cretica (Pignatti 1982).Method.Squash preparations were made on root tips obtained from potted plants, originally growing in nature, cultivated at the botanical garden of Centro Ricerche Floristiche dell'Appennino.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.

Centaurea ambigua
Observations.Centaurea ambigua is endemic to Italy, distributed in central-southern zones, from Emilia-Romagna to Calabria, but doubtfully occurring in Campania.The autonymic subspecies occurs in these same regions, except Tuscany (Peruzzi et al 2014).The only other existing chromosome count for C. ambigua pertains to C. ambigua subsp.nigra (Fiori) Pignatti, which shows 2n = 2x = 18 chromosomes (Baltisberger 1991), different from C. ambigua subsp.ambigua.Hence, C. ambigua subsp.ambigua probably represents a tetraploid unit.Method.Squash preparations were made on root tips obtained from potted plants, originally growing in nature, cultivated at the botanical garden of Centro Ricerche Floristiche dell'Appennino.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Method.Squash preparations were made on root tips obtained from potted plants, originally growing in nature, cultivated at the botanical garden of Centro Ricerche Floristiche dell'Appennino.Root tips were pre-treated with 0.4% colchicine for 3 h and then fixed in Carnoy fixative solution for 1 h.After hydrolysis in 1N HCl at 60 °C, the tips were stained in leuco-basic fuchsin.
Observations.This subspecies is endemic to central (Umbria, Latium, and Abruzzo, doubtful in Marche) and southern Italy (Peruzzi et al. 2014).The chromosome number shown is the same found in H. viridis L. subsp.viridis, as well as in most other Helleborus species (Rice et al. 2014).