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•Zanthoxylum taxa with simple perianths derived from species with sepals and petals.•The monotypic Toddalia is nested within Zanthoxylum.•The genus is inferred to have originated in ...Eurasia in the Paleocene or Eocene.•Zanthoxylum likely crossed both the North Atlantic and the Bering Land Bridges.•Hawaiian taxa might be older than the islands and may be the result of hybridization.
Zanthoxylum L. (prickly ash) is the only genus in the Citrus L. family (Rutaceae) with a pantropical distribution. We present the first detailed phylogenetic and biogeographic study of the genus and its close relatives in the proto-Rutaceae group. Our phylogenetic analyses based on two plastid and two nuclear markers show that the genus Toddalia Juss. is nested within Zanthoxylum, that earlier generic and intrageneric classifications need revision, and that the homochlamydeous flowers of the temperate species of Zanthoxylum are the result of a reduction from heterochlamydeous flowers. The biogeographic analyses reveal a Eurasian origin of Zanthoxylum in the Paleocene or Eocene with successive intercontinental or long-range migrations. Zanthoxylum likely crossed the North Atlantic Land Bridges to colonize the Americas in the Eocene, and migrated back to the Old World probably via the Bering Land Bridge in the Oligocene or Miocene. Zanthoxylum also colonized several Pacific Islands and the Hawaiian clade shows phylogenetic incongruence between the plastid and nuclear datasets, suggesting hybridization. The Hawaiian species are one of the rare examples of endemic Hawaiian lineages that are older than the current main islands.
The Rutaceae are the largest family in number of species in the order Sapindales, with 162 genera and ca. 2085 species, mainly in (sub)tropical regions. The family is well distributed in the ...Americas, with 51 genera and 412–415 species, most of them in the tropical America, with 48 genera (46 endemic to this region), and 350–400 species. Forty-nine genera are restricted to America, only
Thamnosma
(also present in African) and (sub)tropical worldwide
Zanthoxylum
also occurring in other continents. Growing knowledge about the group, especially along the last 25 years, has led to a great internal rearrangement in the family systematics, mainly due to phylogenetic studies based on molecular data. In addition, studies of group reviews, descriptions of new species, and anatomical, cytogenetic, phytochemical, biogeographic and other studies have greatly expanded the knowledge about the evolution of the group. The present work provides a comprehensive overview of these studies in the Rutaceae, with an emphasis on taxa that occur in the American continent, notably in the Neotropical Region, and indicates groups that still need more in-depth studies, specially in a systematic point of view.
Changes in leaf anatomy and ultrastructure are associated with physiological performance in the context of plant adaptations to climate change. In this study, we investigated the isolated and ...combined effects of elevated atmospheric CO2 concentration (CO2) up to 600 μmol mol-1 (eC) and elevated temperature (eT) to 2°C more than the ambient canopy temperature on the ultrastructure, leaf anatomy, and physiology of Panicum maximum Jacq. grown under field conditions using combined free-air carbon dioxide enrichment (FACE) and temperature free-air controlled enhancement (T-FACE) systems. Plants grown under eC showed reduced stomatal density, stomatal index, stomatal conductance (gs), and leaf transpiration rate (E), increased soil-water content (SWC) conservation and adaxial epidermis thickness were also observed. The net photosynthesis rate (A) and intrinsic water-use efficiency (iWUE) were enhanced by 25% and 71%, respectively, with a concomitant increase in the size of starch grains in bundle sheath cells. Under air warming, we observed an increase in the thickness of the adaxial cuticle and a decrease in the leaf thickness, size of vascular bundles and bulliform cells, and starch content. Under eCeT, air warming offset the eC effects on SWC and E, and no interactions between CO2 and temperature for leaf anatomy were observed. Elevated CO2 exerted more effects on external characteristics, such as the epidermis anatomy and leaf gas exchange, while air warming affected mainly the leaf structure. We conclude that differential anatomical and physiological adjustments contributed to the acclimation of P. maximum growing under elevated CO2 and air warming, improving the leaf biomass production under these conditions.
The Brazilian red propolis (BRP) constitutes an important commercial asset for northeast Brazilian beekeepers. The role of
(L.) Taub. (Fabaceae) as the main botanical source of this propolis has been ...previously confirmed. However, in addition to isoflavonoids and other phenolics, which are present in the resin of
, samples of BRP are reported to contain substantial amounts of polyprenylated benzophenones, whose botanical source was unknown. Therefore, field surveys, phytochemical and chromatographic analyses were undertaken to confirm the botanical sources of the red propolis produced in apiaries located in Canavieiras, Bahia, Brazil. The results confirmed
as the botanical source of liquiritigenin (
), isoliquiritigenin (
), formononetin (
), vestitol (
), neovestitol (
), medicarpin (
), and 7-
-neovestitol (
), while
L.f. (Clusiaceae) is herein reported for the first time as the botanical source of polyprenylated benzophenones, mainly guttiferone E (
) and oblongifolin B (
), as well as the triterpenoids
-amyrin (
) and glutinol (
). The chemotaxonomic and economic significance of the occurrence of polyprenylated benzophenones in red propolis is discussed.
Several Rutaceae species have petioles with a swollen apical and/or a basal region and a thinner middle portion. These swollen petiolar regions are morphologically similar to pulvini but are ...recognized by an array of other nomenclatures. We hypothesized that the swollen regions in Rutaceae petioles present anatomical features in keeping with pulvini. We accessed the anatomical features of the petioles in 11 species of Rutaceae belonging to four subfamilies, comparing the swollen and middle petiolar regions. Samples were cross-sectioned using razor blade and stained with Astra Blue and Safranin. Other samples were embedded in methacrylate resin; cross and longitudinal sections were obtained using a rotating microtome and stained with toluidine Blue. Semi-permanent and permanent slides were analyzed using a light microscope. Cortex is significantly wider than in the middle petiolar portion in the swollen petiolar regions. Collenchyma and parenchyma are present in the cortex in all the petiolar regions; sclerenchyma cells are more commonly observed in the middle petiolar region. Secondary growth occurs in all the petiolar regions, but it is more well established in the middle portion of petioles. Septate fibers with non-lignified walls and gelatinous fibers occur externally to the phloem in the swollen, but not in the middle petiolar regions—such petiolar region exhibits only perivascular fibers with completely lignified walls. Articulations were observed only in
Citrus
×
limonia
. Several anatomical features observed in the swollen petiolar regions in Rutaceae are similar to those described to pulvini in other Angiosperms and can be associated with lower rigidity of this region. However, considering the lack of records on the occurrence of leaf movement in this family so far, we suggest the use of “pulvinus-like thickenings” in Rutaceae petioles, and the terms “distal pulvinus-like thickening” and “proximal pulvinus-like thickenings” for the thickened regions near the apex and base of the leaf, respectively. Ultrastructural and leaf movement studies in Rutaceae are needed to clarify the nature and of the thickened petiole regions in the family.
Subtribe Galipeinae (tribe Galipeeae, subfamily Rutoideae) is the most diverse group of Neotropical Rutaceae, with 28 genera and approximately 130 species. One of its genera is Almeidea, whose ...species are morphologically similar to those of the genus Conchocarpus. Species of Almeidea occur in the Atlantic Rain Forest of Eastern Brazil, with one species (Almeidea rubra) also present in Bolivia. The objective of this study was to perform a phylogenetic analysis of Almeidea, using a broader sampling of Galipeinae and other Neotropical Rutaceae, the first such study focused on this subtribe. To achieve this objective, morphological data and molecular data from the nuclear markers ITS-1 and ITS-2 and the plastid markers trnL-trnF and rps16 were obtained. Representatives of eight genera of Galipeinae and three genera of Pilocarpinae (included also in Galipeeae) and Hortia (closely related to Galipeeae) were used. Five species of Almeidea and seven of Conchocarpus were included, given the morphological proximity between these two genera. Individual (for each molecular marker) and combined phylogenetic analyses were made, using parsimony and Bayesian inference as optimization criteria. Results showed Galipeinae as monophyletic, with the species of Almeidea also monophyletic (supported by the presence of pantocolporate pollen) and nested in a clade with a group of species of Conchocarpus, a non-monophyletic group. Additionally, C. concinnus appeared in a group with Andreadoxa, Erythrochiton, and Neoraputia, other members of Galipeinae. As a result, Conchocarpus would be monophyletic only with the exclusion of a group of species related to C. concinnus and with the inclusion of all species of Almeidea with the group of species of Conchocarpus that includes its type species, C. macrophyllus. Thus, species of Almeidea are transferred to Conchocarpus, and the new combinations are made here.
Kunth is the most diverse genus of the South American subfamily Barnadesioideae (Asteraceae), comprising 33 species that occur in tropical Andes, Atlantic Forest, Caatinga, Cerrado, and Chaco. Based ...on distribution, variation in anther apical appendages, and leaf venation pattern, it has traditionally been divided into two subgenera, namely,
and
. Further, based on involucre size and capitula arrangement, two sections have been recognized within subgenus
:
and
(=
). Here, we report a phylogenetic analysis performed to test the monophyly of
and its infrageneric classification based on molecular data from three non-coding regions (
L-
F,
A-
H, and ITS), using a broad taxonomic sampling of
and representatives of all nine genera of Barnadesioideae. Moreover, we used a phylogenetic framework to investigate the evolution of the morphological characters traditionally used to recognize its infrageneric groups. Our results show that neither
nor its infrageneric classification are currently monophyletic. Based on phylogenetic, morphological, and biogeographical evidence, we propose a new circumscription for
, elevating subgenus
to generic rank and doing away with the infrageneric classification. Ancestral states reconstruction shows that the ancestor of
probably had acrodromous leaf venation, bifid anther apical appendages, involucres up to 18 mm in length, and capitula arranged in synflorescence.