RESUMO
The Irano-Turanian region is one of the world's richest floristic regions and the centre of diversity for numerous xerophytic plant lineages. However, we still have limited knowledge on the timing of evolution and biogeographic history of its flora, and potential drivers of diversification remain underexplored. To fill this knowledge gap, we focus on the Eurasian genus Jurinea (ca. 200 species), one of the largest plant radiations that diversified in the region. We applied a macroevolutionary integrative approach to explicitly test diversification hypotheses and investigate the relative roles of geography vs. ecology and niche conservatism vs. niche lability in speciation processes. To do so, we gathered a sample comprising 77% of total genus richness and obtained data about (1) its phylogenetic history, recovering 502 nuclear loci sequences; (2) growth forms; (3) ecological niche, compiling data of 21 variables for more than 2500 occurrences; and (4) paleoclimatic conditions, to estimate climatic stability. Our results revealed that climate was a key factor in the evolutionary dynamics of Jurinea. The main diversification and biogeographic events that occurred during past climate changes, which led to colder and drier conditions, are the following: (1) the origin of the genus (10.7 Ma); (2) long-distance dispersals from the Iranian Plateau to adjacent regions (â¼7-4 Ma); and (3) the diversification shift during Pliocene-Pleistocene Transition (ca. 3 Ma), when net diversification rate almost doubled. Our results supported the pre-adaptation hypothesis, i.e., the evolutionary success of Jurinea was linked to the retention of the ancestral niche adapted to aridity. Interestingly, the paleoclimatic analyses revealed that in the Iranian Plateau long-term climatic stability favoured old-lineage persistence, resulting in current high species richness of semi-arid and cold adapted clades; whereas moderate climate oscillations stimulated allopatric diversification in the lineages distributed in the Circumboreal region. In contrast, growth form lability and high niche disparity among closely related species in the Central Asian clade suggest adaptive radiation to mountain habitats. In sum, the radiation of Jurinea is the result of both adaptive and non-adaptive processes influenced by climatic, orogenic and ecological factors.
Assuntos
Asteraceae , Evolução Biológica , Filogenia , Irã (Geográfico) , FilogeografiaRESUMO
Twenty-two flavonoids were isolated from the leaves and stems of Sedum japonicum subsp. oryzifolium (Crassulaceae). Of these compounds, five flavonoids were reported in nature for the first time, and identified as herbacetin 3-O-xyloside-8-O-glucoside, herbacetin 3-O-glucoside-8-O-(2'''-acetylxyloside), gossypetin 3-O-glucoside-8-O-arabinoside, gossypetin 3-O-glucoside-8-O-(2'''-acetylxyloside) and hibiscetin 3-O-glucoside-8-O-arabinoside via UV, HR-MS, LC-MS, acid hydrolysis and NMR. Other seventeen known flavonoids were identified as herbacetin 3-O-glucoside-8-O-arabinoside, herbacetin 3-O-glucoside-8-O-xyloside, gossypetin 3-O-glucoside-8-O-xyloside, quercetin, quercetin 3-O-glucoside, quercetin 3-O-xylosyl-(1â2)-rhamnoside-7-O-rhamnoside, quercetin 3-O-rhamnoside-7-O-glucoside, kaempferol, kaempferol 3-O-glucoside, kaempferol 7-O-rhamnoside, kaempferol 3,7-di-O-rhamnoside, kaempferol 3-O-glucoside-7-O-rhamnoside, kaempferol 3-O-glucosyl-(1â2)-rhamnoside-7-O-rhamnoside, kaempferol 3-O-xylosyl-(1â2)-rhamnoside, kaempferol 3-O-xylosyl-(1â2)-rhamnoside-7-O-rhamnoside, myricetin 3-O-glucoside and cyanidin 3-O-glucoside. Some flavonol 3,8-di-O-glycosides were found in Sedum japonicum subsp. oryzifolium as major flavonoids in this survey. They were presumed to be the diagnostic flavonoids in the species. Flavonoids were reported from S. japonicum for the first time.
Assuntos
Crassulaceae , Sedum , Quempferóis , Quercetina/química , Flavonoides/química , Glucosídeos/química , Glicosídeos/químicaRESUMO
The floras on the highest mountains in tropical eastern Africa are among the most unique floras in the world. Despite the exceptionally high concentration of endemic species, these floras remain understudied from an evolutionary point of view. In this study, we focus on the Carduus-Cirsium group (subtribe Carduinae) to unravel the evolutionary relationships of the species endemic to the tropical Afromontane and Afroalpine floras, aiming to improve the systematics of the group. We applied the Hyb-Seq approach using the Compositae1061 probe set on 190 samples (159 species), encompassing representatives of all genera of Carduinae. We used two recently developed pipelines that enabled the processing of raw sequence reads, identification of paralogous sequences and segregation into orthologous alignments. After the implementation of a missing data filter, we retained sequences from 986 nuclear loci and 177 plastid regions. Phylogenomic analyses were conducted using both concatenated and summary-coalescence methods. The resulting phylogenies were highly resolved and revealed three distinct evolutionary lineages consisting of the African species traditionally referred to as Carduus and Cirsium. Consequently, we propose the three new genera Afrocarduus, Afrocirsium and Nuriaea; the latter did notably not belong to the Carduus-Cirsium group. We detected some incongruences between the phylogenies based on concatenation vs. coalescence and on nuclear vs. plastid datasets, likely attributable to incomplete lineage sorting and/or hybridization.
RESUMO
A new species Saussurea talungensis S.K.Ghimire & H.K.Rana, sp. nov. (sect. Strictae), from Talung valley of Humla district, Nepal, is described and illustrated. Morphologically, this species resembles Saussurea roylei and Saussurea lanata in habit, though it can be distinguished in having longer leaf petioles, purplish leaf margin, 1 or 3 capitula, shorter phyllaries, shorter receptacle bristles and the same anthers, comparatively shorter corolla with shorter lobes. Phylogenomic analysis also supports S. talungensis as a distinct species of Saussurea. Here, we provide taxonomic note, distribution map and phylogenomic inference to distinguish the new species and its allied members.
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BACKGROUND: Myanmar is one of the hotspots of biodiversity and is a rapidly developing country. Performing floristic research in Myanmar is an urgent issue, and ethnobotanical studies of wild edible plants (WEPs) will provide new information on natural plant resources. METHOD: Ethnobotanical data were collected in three villages with different historical backgrounds in Southern Shan State, Myanmar. A total of 19 key informants were interviewed, and specimens were collected in the fields with the participation of key informants in June-July 2015. Group discussions were organized during 2016 and 2017 to reinforce the information on use of WEPs. DNA barcoding was used to facilitate species identification. RESULTS: A total of 83 species from 44 families of angiosperms were recorded as WEPs. Most of the species were used as wild vegetables (47 species), followed by fruits and nuts (31 species). Eighteen WEPs were consumed as medicinal foods. Differences in use of WEPs between the communities of the villages were observed. The age class of 30-39 years was more familiar with the environments where they could collect WEPs and had more knowledge of WEPs than did the older groups. The use of Elaeocarpus floribundus as an edible oil is a very interesting tradition. CONCLUSION: WEPs play an important role in the livelihood of local communities. The indigenous society has maintained traditional knowledge of the WEPs. Historical background, land use system and surrounding vegetation could have effects on the variation in the traditional uses of WEPs. Increasing awareness of the importance of WEPs will encourage the conservation of traditional knowledge of indigenous populations.
Assuntos
Conhecimento , Fitoterapia , Plantas Comestíveis , Plantas Medicinais , Adulto , Biodiversidade , Conservação dos Recursos Naturais , Etnobotânica , Humanos , Pessoa de Meia-Idade , MianmarRESUMO
Himalayan snowball plants, which are considered to be an extreme form of downy plants, have very dense trichomes on well-developed bracts that surround the inflorescences. It has been postulated that the downy inflorescences of these plants might serve to keep the interior of inflorescences warmer than the outside and, thus, to protect reproductive cells from low temperatures in their Himalayan habitat. In the present study, we examined the downy inflorescences of Saussurea medusaMaxim. in native habitats in the high alpine zone of the Henduan Mountains in Yunnan, China, and we analyzed the temperature within inflorescences after absorbance of light energy. S. medusais pollinated by bumblebees and we found that its inflorescences accumulated heat not on the inside, but, rather, on the upper surfaces. The thick hollow stems and the overlapping bracts with obvious epinasty might serve not only to retain heat, but also as an insulator to protect the inside against overheating, with apparent local warming of flowers that are located at the tops of plants, which are cone-shaped. We made a model that mimicked the warming of inflorescences, providing support for the hypothesis that the downy bracts of S. medusahave two functions: thermal insulation to protect the inside of flowers and the accumulation of heat on the upper surfaces of the inflorescence. Such a system might be effective in attracting pollinators and also in protecting tissues from extreme variations in temperature.