Phylogeny of Apiaceae subtribe Daucinae and the taxonomic delineation of its genera

Abstract

Scandiceae subtribe Daucinae encompasses umbellifers that have fruits with prominent secondary ridges projecting into wings (former tribe Laserpitieae) or spines (former tribe Caucalideae pro parte). It comprises several economically or medicinally important genera including Cuminum, Daucus, Laser, Laserpitium and Thapsia among others. Recent molecular studies, based mostly on nrDNA ITS sequences, revealed that neither Daucus nor Laserpitium are monophyletic. To address issues of relationships and apply respective nomenclatural changes, we obtained additional ITS sequences as well as independent data from three plastid markers—rps16 intron, rpoC1 intron and rpoB‐trnC intergenic spacer—for a comprehensive sample of the subtribe. We examined data for 260 accessions representing all genera of Daucinae and 81 of its ca. 93 species. Phylogenetic trees were estimated using maximum likelihood and Bayesian inference methods. The results indicate that former Laserpitieae constitute a paraphyletic grade at the base of the spiny‐fruited members of Daucinae while traditionally delimited Daucus and Laserpitium are polyphyletic. To maintain a monophyletic Daucus, we suggest including the following genera and species into its synonymy: Agrocharis, Melanoselinum, Monizia, Pachyctenium, Pseudorlaya, Rouya, Tornabenea, Athamanta dellacellae and Cryptotaenia elegans. The species of Laserpitium occur in seven clades and only six species of the Laserpitium s.str. clade retain the generic name. Several species are transferred to Ekimia, Laser and Thapsia; additionally, a monospecific genus Siler is restored and a new genus, Silphiodaucus, is established. The inclusion of Ammodaucus into Thapsia suggested in an earlier study is not supported. The position of Laserpitium pseudomeum requires further study.

Genotyping-by-sequencing provides the discriminating power to investigate the subspecies of Daucus carota (Apiaceae)

“…The phylogenetic relationships of Daucus were previously reported by Spalik and Downie [88], Spalik et al [89], Spooner et al [35], Arbizu et al [36, 90], Lee and Park [27], and Banasiak et al [37]; all findings supported two main clades. Our two data sets with 10 or 30% missing imputed genotypes also reconstructed the two main clades of Daucus , A and B (Additional file 3: Figure S1 and Additional file 4: Figure S2).…”

“…However, based on our ML results and morphological analysis of members of the D. guttatus complex [90, 111], these three accessions were re-identified as D. guttatus . The paraphyly of the genus Daucus (circumscribed containing Rouya polygama ) was extensively documented using plastid or ribosomal DNA characters [35, 37]. Recent studies [37, 112], using nrDNA ITS sequences and plastid sequences also showed that Rouya polygama groups within the Daucus clade.…”

“…The paraphyly of the genus Daucus (circumscribed containing Rouya polygama ) was extensively documented using plastid or ribosomal DNA characters [35, 37]. Recent studies [37, 112], using nrDNA ITS sequences and plastid sequences also showed that Rouya polygama groups within the Daucus clade.…”

“…Arbizu et al [36] used 94 nuclear orthologs obtained by next-generation sequencing technology to examine multiple accessions per species of Daucus , and could distinguish the species well, including the 2n = 18 species D. syrticus , but not the subspecies of D. carota . Similarly, a recent investigation [37] used ITS sequences and three plastid DNA sequences to study the phylogeny of subtribe Daucinae and showed accessions of the D. carota complex did not group the subspecies together.…”

Tracing insular woodiness in giant Daucus (s.l.) fruit fossils from the Early Pleistocene of Madeira Island (Portugal)

“…Recent phylogenetic studies of the Madeiran endemic genera Monizia Lowe and Melanoselinum Hoffm. proposed inclusion within the genus Daucus L. (Banasiak & al., ). Moreover, a calibrated molecular phylogenetic study that included the Madeiran neoendemic Apiaceae (Spalik & al., ) proposed a Gelasian origin of Daucus (∼2.5 Ma).…”