Premise Lantana and Lippia (Verbenaceae) are two large Linnean genera whose classification has been based on associated fruit traits: fleshy vs. dry fruits and one vs. two seed‐bearing units. We reconstruct evolutionary relationships and the evolution of the two fruit traits to test the validity of these traits for classification. Methods Previous studies of plastid DNA sequences provided limited resolution for this group. Consequently, seven nuclear loci, including ITS, ETS, and five PPR loci, were sequenced for 88 accessions of the Lantana/Lippia clade and three outgroups. Results Neither Lantana nor Lippia is monophyletic. Burroughsia, Nashia, Phyla, and several Aloysia species are included within the clade comprising Lantana and Lippia. We provide a hypothesis for fruit evolution and biogeographic history in the group and their relevance for classification. Conclusions Fleshy fruits evolved multiple times in the Lantana/Lippia clade and thus are not suitable taxonomic characters. Several sections of Lantana and Lippia and the small genera are monophyletic, but Lippia section Zappania is broadly paraphyletic, making circumscription of genera difficult. Lippia sect. Rhodolippia is a polyphyletic group characterized by convergence in showy bracts. Species of Lantana sect. Sarcolippia, previously transferred to Lippia, are not monophyletic. The clade originated and diversified in South America, with at least four expansions into both Central America and the Caribbean and two to Africa. The types species of Lantana and Lippia occur in small sister clades, rendering any taxonomy that retains either genus similar to its current circumscription impossible.
We describe the chromosome numbers and genome sizes of species of the cryptanthoid complex of Bromeliaceae in a phylogenetic framework and their relationship with habitat preferences. The 2C DNA contents varied 2.13-fold among species, ranging from 0.76 to 1.66 pg. A significant difference in DNA content was found among Cryptanthus, Hoplocryptanthus and Rokautskyia. Moreover, species from campos rupestres and the Atlantic Forest had lower and higher genome size values, respectively. The smaller genome sizes of Hoplocryptanthus spp. from campos rupestres may be related with the large genome constraint. The species show a highly conserved ploidy (with 2n = 32 and 34), although the genome sizes varied considerably. The observed variation in chromosome numbers seems to be influenced by dysploidy, but additional investigations are needed. Our study demonstrates that the genome size variation in the cryptanthoid complex species is not strictly related to the phylogenetic relationships and has probably been influenced by different evolutionary processes.
Lippia lacunosa is a Brazilian savanna plant that belongs to the Verbenaceae family. It has been used in folk medicine as a treatment for different diseases. This species represents an endangered Brazilian medicinal plant, and this is the first report documenting a reliable protocol for the in vitro propagation and regeneration of L. lacunosa. Axenic explants were cultivated in MS medium containing different concentrations of naphthalene acetic acid (NAA) to induce root growth. The mean shoot length and the number of roots were highest with 0.06 mg·L-1 NAA. The highest number of buds in shoot regeneration was induced with 2 mg·L-1 6-benzylaminopurine (BA). To obtain a long-term culture, the dwarf shoots were elongated on MS media containing 0.5 mg·L-1 BA alternated with MS containing 2 mg·L-1 BA every 40 days. In the present protocol, the long-term shoots retained the ability to root even after long periods of BA treatment. In addition, we evaluated the nuclear DNA content and ploidy levels, including the occurrence of endopolyploidy, in long-term micropropagated plant leaves using flow cytometry analysis. The plants propagated in vitro over several years possessed nuclear DNA contents ranging from 2.940 to 3.095 pg, and no differences in DNA content were found among in vitro plants or between these plants and the control (L. lacunosa from a greenhouse with a DNA content of 3.08 pg). The flow cytometry analysis also demonstrated that there was no polyploidization. The present study will be useful for biotechnological approaches and provides the first estimate of the nuclear DNA content of this species using flow cytometry.
The genus Agapanthus L'Héritier (Agapanthaceae) is a monocotyledonous, herbaceus and perennial plant group endemic to southern Africa. Ten species have been described for this group, in which three are considered evergreen and seven deciduous plants. Nevertheless, Agapanthus L'Héritier taxonomy is considered very difficult once there are few unique characters and a high plasticity depending on circumstances of growing. This feature takes some authors to believe in the existence of only one species with innumerous varieties.The cytogenetic has been an important tool to aid the plant taxon identification, and to date, all taxa of Agapanthus L'Héritier studied cytologically presented 2n = 30. Although the species possess large chromosomes, few karyological studies has been explored. This work aimed to increase the cytogenetic knowledge of Agapanthus africanus (L.) Hoffmanns by chromosome banding techniques with DAPI / CMA3 and Fluorescent in situ Hybridization (FISH). In addition, flow cytometry was used to determinate DNA content and the percentage of AT / GC nitrogenous bases. Plants studied showed 2n = 30 chromosomes, ranging from 4.34 - 8.55 µm, with karyotype formulae (KF) = 10m + 5sm. The FISH technique revealed one 45S rDNA signal observed proximally to centromere of the chromosome 7, and one 5S rDNA signal observed proximally to centromere of chromosome 9. The 2C DNA content estimated for the species was 2C = 24.4pg, with 59% of AT and 41% of GC. Our data allowed important upgrade for biology and cytotaxonomy of Agapanthus africanus (L.) Hoffmanns, and will be used to future taxonomic and phylogenetics studies, as well as for the chromosome evolution of the genus. APOIO FINANCEIRO: Fapemig, Capes, CNPq
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