Phylogeny, karyotype evolution and taxonomy of Crocus series Verni (Iridaceae)

Abstract

The taxonomically complicated Crocus series Verni is characterized by high intra-and interspecific variability of karyotypes (2n = 8-23). With the aim to get more insights into complex karyotype evolution and to clarify the taxonomy of this group, we combined morphological (twelve characters), molecular (chloroplast DNA: trnL-trnF, ndhF; nuclear DNA: ITS, pCOSAt103) and karyological analyses. Samples of different populations of C. etruscus, C. ilvensis, C. kosaninii, C. tommasinianus, C. vernus sensu lato and C. longiflorus (series Longiflori) were analyzed. Quantitative karyotype parameters were calculated for all taxa involved based on the available literature. For the taxon traditionally known as C. vernus, the analyses suggest that it should be split in five species: C. heuffelianus, C. neapolitanus, C. neglectus sp. nov., C. siculus and C. vernus. The comparison of genome total haploid lengths suggests that in the evolution of the group polyploidization only played a role within the C. vernus species complex, where we also detected two hybridization events. In all other taxa, chromosome evolution is probably characterized by chromosome fusions and fissions, sometimes affecting the entire haploid chromosome set. Comparative cytogenetics of the group indicates that series Verni is subject to a peculiar type of unequal change in chromosome size, i.e., that not both chromosome arms gain or lose equally in DNA content. As a taxonomic consequence of our study, series Verni is newly circumscribed, now including the autumn-flowering C. longiflorus and excluding C. baytopiorum.

Phylogeny, geographic distribution, and new taxonomic circumscription of the Crocus reticulatus species group (Iridaceae)

“…The genus Crocus L. consists currently of about 160 recognized species (Mathew, 1982;Petersen et al, 2008;Kerndorff and Pasche, 2011;Kerndorff et al, 2011Kerndorff et al, , 2013Peruzzi and Carta, 2011;Ranđelović et al, 2012;Harpke et al, 2014) occurring from western Europe and northwestern Africa to western China, with the center of species diversity on the Balkan Peninsula and in Turkey. Many crocuses are known as popular ornamentals, and saffron, the dried styles of C. sativus L., is one of the world's most expensive spices.…”

A proposal for a multivariate quantitative approach to infer karyological relationships among taxa

“…For Cyananthus Wallich ex Bentham, 1836 (Campanulaceae) and for Crocus Linnaeus, 1753 ser. Verni Mathew, 1982 (Iridaceae), the data were derived by the recent papers by Chen et al (2014) and Harpke et al (2014), respectively. Most of these papers report also information on the phylogenetic relationships among groups (for Cyananthus available in Zhou et al 2013), as inferred from molecular systematic studies.…”

Notulae to the Italian native vascular flora: 3

“…The occurrence of this species in Emilia-Romagna is a matter of debate since a long time. Currently considered as a narrow endemic to Toscana (Carta et al 2010, Harpke et al 2015, Peruzzi et al 2017, it was indeed doubtfully reported for Emilia-Romagna by Mathew (1982: "possibly also near Parma"), recorded by Alessandrini (1983), Alessandrini & Bonafede (1996), Alessandrini & Branchetti (1997), and Mazzoni et al (2001) for several localities. Later, it was excluded from the regional flora by Carta et al (2010) According to Bartolucci et al (2016b), this species was so far only historically recorded from Umbria.…”