Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Plant Divers ; 46(1): 144-148, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38343589

RESUMEN

•The first reported mitochondrial genome (Cinnamomum chekiangense) of the Lauraceae family.•The mitogenome of C. chekiangense retains almost all of the ancestral protein-coding genes and has the highest RNA editing number in angiosperms.•Both of the plastid and mitochondrial phylogenetic trees support the magnoliids as a sister group of monocots and eudicots.

2.
BMC Plant Biol ; 23(1): 155, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36945024

RESUMEN

BACKGROUND: Understanding the relationship between human evolution and environmental changes is the key to lifting the veil on human origin. The hypothesis that environmental changes triggered the divergence of humans from apes (ca. 9.3-6.5 million years ago, Ma) has been poorly tested because of limited continuous environmental data from fossil localities. Lufengpithecus (12.5-6.0 Ma) found on the southeastern margin of the Tibetan Plateau (SEMTP) across the ape-human split provides a good chance for testing this hypothesis. RESULTS: Here, we reconstructed the habitats of L. keiyuanensis (12.5-11.6 Ma) with comprehensive vegetation, climate, and potential food web data by palaeobotanical evidence, together with other multidisciplinary data and partly tested the environment-driven hypothesis by revealing the living conditions of Lufengpithecus. CONCLUSION: A detailed comparison of hominoids on different continents reveals their behaviour and fate divergence across the ape-human split against the background of global climate change, i.e., the stable living conditions of SEMTP not only provided a so-called 'refuge' for arboreal Lufengpithecus but also acted as a 'double-edged sword', preventing their further evolution while vegetation shifts in East Africa probably stimulated the emergence of human bipedalism, and the intense climatic changes in Europe possibly prevented those hominoids from surviving that time interval. Our findings provide interesting insight into the environmental impacts on the behavioural evolution of hominoids.


Asunto(s)
Hominidae , Condiciones Sociales , Animales , Humanos , Filogenia , Asia Oriental , Fósiles , Evolución Biológica
3.
Ecol Evol ; 12(10): e9378, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36203627

RESUMEN

Taxonomy of Cinnamomum Schaeff. of Lauraceae remains problematic because recent phylogenetic studies have suggested that this genus is not monophyletic. In this study, we assembled three sequence matrices including plastomes (datamatrix I), nrITS sequences alone (datamatrix II), and nrITS plus plastid psbA-trnH sequences (datamatrix III) of the Cinnamomum-Ocotea complex of Lauraceae and conducted a new phylogenetic study with thusfar the most extensive species sampling of the Cinnamomum-Ocotea group. We determined that the Old World Cinnamomum is diphyletic: sect. Camphora Meisn. is sister to Sassafras J.Presl and sect. Cinnamomum is sister to the African Kuloa Trofimov & Rohwer. A recent study indicated that characters of leaf micromorphological anatomy can define the two clades: one possessing reticulate periclinal and the other having non-reticulate periclinal walls. As result, we divided the genus Cinnamomum of Lauraceae into two genera, i.e., Cinnamomum and Camphora Fabr. The generic name Cinnamomum is retained for those species mainly having reticulate periclinal epidermal cell walls, inconspicuous non-perulate terminal buds and usually tripliveined leaves; the oldest generic name, Camphora, is applied to the second group which contains those species mainly possessing non-reticulate periclinal epidermal cell walls, prominent perulate terminal buds and pinnately-veined leaves. A census of the species and their type specimens listed under Cinnamomum in Asia resulted in the transfer of 18 species to Camphora, including 15 new combinations.

4.
Biology (Basel) ; 11(10)2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-36290345

RESUMEN

Both Trapa L. and the extinct Hemitrapa Miki are aquatic plants in the family Lythraceae, with abundant fossil records in Eurasia and North America in the Cenozoic. However, documented materials are mainly based on fruit and pollen grains without reliable leaf fossils. Here, we report fossil leaves, fruit, and roots of Trapa and fruit of Hemitrapa from the late Eocene of Weinan, the Weihe Basin of central China. The fossil leaves are identified as a new species, Trapa natanifolia Z. C. Han et H. Jia sp. nov., which represents the earliest known record of a Trapa leaf fossil. It is remarkably similar to extant species of Trapa, mostly due to the unique inflated petiole structures found in both of them. While displaying prominent intergeneric differences, the incomplete fossil fruits are assigned to Trapa sp. indet. and Hemitrapa sp. indet. The former is the earliest fossil fruit record of Trapa, and the latter represents the earliest fossil record of Hemitrapa found in Asia. These new fossil discoveries suggest that the divergence of Trapa and Hemitrapa occurred at least by the late Eocene. It is believed that modern Trapa most likely originated in China. Furthermore, this unexpected aquatic plant fossil assemblage indicates that central China was warm and humid, with freshwater ponds or lakes, in the late Eocene and not as arid as previously thought.

5.
Commun Biol ; 5(1): 966, 2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-36109665

RESUMEN

Tree lycopsids prospered in the Late Devonian and constituted a major part of the Late Paleozoic forest ecosystem that deeply impacted the Earth's climate. However, the fertile organs of these early tree lycopsids display low morphological disparity, which has hampered further knowledge about their ecological habit. Here, we report Omprelostrobus gigas gen. et sp. nov. from the Upper Devonian (Famennian) Wutong Formation at Changxing, Zhejiang, China. The collection includes aerial axes, strobili and associated roots. The strobili are the largest among coeval lycopsids to our knowledge, and are divided into proximal and distal portions by dimorphic sporophylls with differentiated laminae and probable strong photosynthetic capacity. The associated but not attached roots displaying multiple isotomous branches lack rootlets and typical rootlet scars. The varied strobili sizes of early tree lycopsids were relatively independent of their body plan, but the large strobili could suggest increased reproductive investment to overcome the disadvantages of the disturbed flooded habitat.


Asunto(s)
Fósiles , Árboles , Evolución Biológica , Ecosistema , Cono de Planta
6.
Biology (Basel) ; 11(9)2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-36138740

RESUMEN

The Neogene environment and paleovegetation of today's semi-arid and arid Central Asia remain elusive. Little is known about the effect of paleoclimatic change on the distribution and ecological response mechanisms of aquatic plants, especially on the Tibetan Plateau. Here, we report a new species of Nelumbo Adanson, including leaves, receptacles, and fruits, namely Nelumbo delinghaensis sp. nov., from the Upper Youshashan Formation of the upper Middle Miocene in the northern Qaidam Basin on the Tibetan Plateau. The new species comprises centrally peltate leaves with 12−15 actinodromous primary veins and a receptacle embedded with ca. 15−30 fruits, with an unlobed central disc. Megafossils of lotus from northwest China broaden the geographical and stratigraphic ranges of Nelumbo. Our findings suggest that a large freshwater lake body surrounded by temperate forests and grassland developed in the Qaidam Basin during the late Middle Miocene, in sharp contrast to the present desert vegetation. The climate used to be sufficiently warm and moist enough to support a forest-steppe ecosystem with abundant freshwater bodies.

7.
PhytoKeys ; 211: 75-80, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36760733

RESUMEN

The type of Cycasdebaoensis Y.C.Zhong & C.J.Chen (Y.C.Zhong 8762) consists of nine duplicates in PE. Our new investigation of the type collection suggests that the type includes at least two different gatherings which should be considered as syntypes. For nomenclatural purposes, we lectotypify the name Cycasdebaoensis with the herbarium sheet PE00047578 and consider other duplicates in PE and GXMI as isolectotypes. The seeds in the capsule (Y.C.Zhong s.n. collected in Oct 1998) are considered as a syntype.

8.
Innovation (Camb) ; 2(2): 100110, 2021 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-34557760

RESUMEN

The evolution of the Asian monsoon from the Late Oligocene to the Early Miocene is poorly understood. Here, we first reconstruct the precipitation data of central Tibet during 26-16 million years ago (Ma), applying the coexistence approach to sedimentary pollen data, and detect an intensified Asian monsoon with ∼1.35 Ma and ∼0.33 Ma cycles. Paleoclimate modeling is used to show the importance of paleogeographic location in the development of the paleomonsoon. In addition, the results of spectral analysis suggest that the fluctuations in the Asian monsoon during 26-16 Ma can be attributed to the long-period cyclicities in obliquity (∼1.2 Ma). These findings provide climate data that can be used to understand the Asian monsoon evolution during the Late Oligocene to Early Miocene and highlight the effects of paleogeographic patterns and long-period orbital forcings on the tectonic-scale evolution of the Asian monsoon.

9.
J Am Dent Assoc ; 152(8): 641-652, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34325780

RESUMEN

BACKGROUND: Opioid misuse is a widespread public health problem, and opioids are often prescribed in the dental environment. These recommendations provide alternatives to opioids to reduce or eliminate dental procedure-related acute pain. METHODS: A multidisciplinary working group developed these clinical recommendations to specifically address procedure-related acute pain. These recommendations, which are based on published peer-reviewed research and guidelines, include therapies used before, during, and after dental procedures. When evidence is not definitive, the best practices, which are based on experts' consensus, are included. The recommendations are not intended to be exhaustive. RESULTS: These recommendations are a summary of the evidence and best practices for opioid alternatives to treat acute pain related to dental procedures. CONCLUSIONS: Dental providers should prioritize opioid stewardship when managing procedure-related pain with strategies such as thorough preprocedure pain assessment, minimally invasive techniques, preemptive analgesia, intraprocedure pain management, and appropriately selected postprocedure pharmacologic therapy. PRACTICAL IMPLICATIONS: These recommendations are a concise resource for clinical providers. It is important to address patients' procedure-related pain, using nonopioids whenever possible. Alternatives are outlined, allowing providers to make informed decisions.


Asunto(s)
Trastornos Relacionados con Opioides , Veteranos , Analgésicos Opioides/efectos adversos , Consenso , Humanos , Trastornos Relacionados con Opioides/tratamiento farmacológico , Trastornos Relacionados con Opioides/prevención & control , Manejo del Dolor
10.
Ecol Evol ; 11(24): 17615-17624, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35003628

RESUMEN

Floral characters are important for the systematics of the Lauraceae. However, structure and development of the flowers remain poorly known in the family. In this study, we observed the variation and early development of flowers of Beilschmiedia appendiculata, which belongs to the Cryptocarya clade of the family. The results indicate that the shoot apical meristems (SAMs) of the floral buds are enlarged and become a platform for the programmed initiation of the floral organs; floral organs develop basically in an acropetal pattern; phyllotaxis is whorled, initiation of floral primordia within a whorl is asynchronous; floral merosity is extremely variable, for example, dimerous, trimerous, tetramerous, dimerous plus trimerous, and trimerous plus tetramerous. In addition, this species has lost the innermost staminal whorl and glands are not closely associated with stamens of the third staminal whorl, which is unusual in the family Lauraceae. Our new observations broaden our knowledge of the variation of floral structure in Beilschmiedia and pose a fundamental question regarding the ecology underlying the lability of floral organs in B. appendiculata.

12.
BMC Plant Biol ; 19(1): 402, 2019 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-31519148

RESUMEN

BACKGROUND: Around the Cretaceous-Paleogene (K-Pg) boundary, an obvious global cooling occurred, which resulted in dramatic changes in terrestrial ecosystems and the evolutionary trends of numerous organisms. However, how plant lineages responded to the cooling has remained unknown until now. Between ca. 70-60 Ma Mesocyparis McIver & Basinger (Cupressaceae), an extinct conifer genus, was distributed from eastern Asia to western North America and provides an excellent opportunity to solve this riddle. RESULTS: Here we report a new species, Mesocyparis sinica from the early Paleocene of Jiayin, Heilongjiang, northeastern China. By integrating lines of evidence from phylogeny and comparative morphology of Mesocyparis, we found that during ca.70-60 Ma, the size of seed cone of Mesocyparis more than doubled, probably driven by the cooling during the K-Pg transition, which might be an effective adaptation for seed dispersal by animals. More importantly, we discovered that the northern limit of this genus, as well as those of two other arboreal taxa Metasequoia Miki ex Hu et Cheng (gymnosperm) and Nordenskioldia Heer (angiosperm), migrated ca.4-5° southward in paleolatitude during this time interval. CONCLUSIONS: Our results suggest that the cooling during the K-Pg transition may have been responsible for the increase in size of the seed cone of Mesocyparis and have driven the migration of plants southwards.


Asunto(s)
Fósiles , Evolución Biológica , Cycadopsida/fisiología , Ecosistema , Magnoliopsida/fisiología , Plantas
13.
BMC Evol Biol ; 18(1): 125, 2018 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-30157769

RESUMEN

BACKGROUND: Male cones of modern Ephedraceae are compound and compact. No fossil evidence has so far been found to support an origin of the compact compound male cone from a hypothetical loosely-arranged shoot system. RESULTS: Here we describe a new macrofossil taxon, Eamesia chinensis Yang, Lin, Ferguson et Wang, gen. et sp. nov., from the Early Cretaceous of western Liaoning, northeastern China. It was an ephedroid shrub bearing male spikes terminal to twigs, but differs from modern Ephedraceae by its loosely-arranged male cones, the axillary male shoot consisting of an elongated synangiophore on which leaf-like foliar organs were inserted, and four sessile synangia terminal to the apex. CONCLUSIONS: The morphology of this fossil suggests that the modern compact male cone of Ephedra was indeed derived from a once loosely-arranged shoot system, and the male reproductive unit originated from a once elongated axillary male shoot. This new fossil species thus provides a transitional link from the hypothetical ancestral shoot system to the modern compact morphology. Changes of habitat from closed humid forests to open dry deserts and shifts of the pollination syndrome may have acted as the driving forces behind this morphological evolution.


Asunto(s)
Evolución Biológica , Fósiles , Tracheophyta/anatomía & histología , Tracheophyta/fisiología , Bosques , Polinización
14.
Data Brief ; 18: 1022-1046, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29900271

RESUMEN

The data presented in this article are related to the research article entitled "Pollen spectrum, a cornerstone for tracing the evolution of the eastern central Asian desert" (JQSR 5260) (Lu et al., 2018) [1] In this paper, we supply a dataset, which provides a descriptive and general summary of pollen characteristic of desert dominant species in the eastern arid central Asia (ACA). The other important component is the illustration on pollen grains traits under light microscopy (LM) and scanning electron microscopy (SEM). Pollen grains of 56 species are extracted from voucher specimens from the PE herbarium at the Institute of Botany. It is worth noting that these species own special distribution patterns in China. The distribution maps are plotted using the Google Maps and the species distribution data at the county level supplied by the Chinese Virtual Herbarium (http://www.cvh.ac.cn/).

15.
PLoS One ; 12(10): e0186358, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29028818

RESUMEN

Generic delimitation in the Beilschmiedia group of the Lauraceae remains ambiguous because flowering specimens of a few genera with confined distribution are poorly represented in herbaria, and a few floral characters important for taxonomy are still poorly known. Syndiclis is sporadically distributed in southwestern China, and is represented in the herbaria by only a few flowering specimens. We conducted field investigations to collect floral materials of four species and observed structures and ontogeny of the tiny flowers using both light microscopy (LM) and scanning electron microscopy (SEM). The results show that the genus Syndiclis possesses flowers with huge variation in both merosity and organ number. Flowers of the genus are dimerous, trimerous, or tetramerous, or have mixed merosity with monomerous and dimerous, or dimerous and trimerous, or trimerous and tetramerous whorls. The number of staminodes ranges from two to eight, depending on floral merosity, and on how many stamens of the third androecial whorl are reduced to staminodes. The staminodes of the fourth androecial whorl are comparable to the staminodes in Potameia, but the staminodes of the third androecial whorl of Syndiclis are relatively larger than the staminodes in Potameia. They are erect or curved inwards, covering the ovary. The anthers are usually two-locular, but rarely one-locular or three-locular. Each stamen of the third androecial whorl bears two conspicuous and enlarged glands at the base. The lability of floral merosity and organ number of Syndiclis may have been caused by changes of pollination system and loss of special selective pressures that are present in most Lauraceous plants with fixed floral organ number. This study furthers our understanding of variation and evolution of a few important characters of the Beilschmiedia group and provides essential data for a revised generic classification of the group.


Asunto(s)
Flores/anatomía & histología , Flores/crecimiento & desarrollo , Lauraceae/anatomía & histología , Lauraceae/crecimiento & desarrollo , Desarrollo de la Planta , Especificidad de la Especie
16.
Sci Rep ; 5: 14212, 2015 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-26369980

RESUMEN

Cenozoic plant relicts are those groups that were once widespread in the Northern Hemisphere but are now restricted to some small isolated areas as a result of drastic climatic changes. They are good proxies to study how plants respond to climatic changes since their modern climatic requirements are known. Herein we look at the modern distribution of 65 palaeoendemic genera in China and compare it with the Chinese climatic pattern, in order to find a link between the plant distribution and climate. Central China and Taiwan Island are shown to be diversity centres of Cenozoic relict genera, consistent with the fact that these two regions have a shorter dry season with comparatively humid autumn and spring in China. Species distribution models indicate that the precipitation parameters are the most important variables to explain the distribution of relict genera. The Cenozoic wide-scale distribution of relict plants in the Northern Hemisphere is therefore considered to be linked to the widespread humid climate at that time, and the subsequent contraction of their distributional ranges was probably caused by the drying trend along with global cooling.


Asunto(s)
Biodiversidad , Sequías , Ecosistema , Plantas , Estaciones del Año , China , Clima
17.
Sci Rep ; 5: 10379, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25976244

RESUMEN

The area and elevation of the Tibetan Plateau over time has directly affected Asia's topography, the characteristics of the Asian monsoon, and modified global climate, but in ways that are poorly understood. Charting the uplift history is crucial for understanding the mechanisms that link elevation and climate irrespective of time and place. While some palaeoelevation data are available for southern and central Tibet, clues to the uplift history of northern Tibet remain sparse and largely circumstantial. Leaf fossils are extremely rare in Tibet but here we report a newly discovered early Miocene barberry (Berberis) from Wudaoliang in the Hoh-Xil Basin in northern Tibet, at a present altitude of 4611 ± 9 m. Considering the fossil and its nearest living species probably occupied a similar or identical environmental niche, the palaeoelevation of the fossil locality, corrected for Miocene global temperature difference, is estimated to have been between 1395 and 2931 m, which means this basin has been uplifted ~2-3 km in the last 17 million years. Our findings contradict hypotheses that suggest northern Tibet had reached or exceeded its present elevation prior to the Miocene.


Asunto(s)
Altitud , Berberis/fisiología , Clima , Hojas de la Planta/fisiología , Fenómenos Fisiológicos de las Plantas , Ambiente , Fósiles , Geografía , Filogenia , Temperatura , Tibet
18.
PLoS One ; 10(3): e0119412, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25763576

RESUMEN

Modern pollen records have been used to successfully distinguish between specific prairie types in North America. Whether the pollen records can be used to detect the occurrence of Eurasian steppe, or even to further delimit various steppe types was until now unclear. Here we characterized modern pollen assemblages of meadow steppe, typical steppe and desert steppe from eastern Eurasia along an ecological humidity gradient. The multivariate ordination of the pollen data indicated that Eurasian steppe types could be clearly differentiated. The different steppe types could be distinguished primarily by xerophilous elements in the pollen assemblages. Redundancy analysis indicated that the relative abundances of Ephedra, Tamarix, Nitraria and Zygophyllaceae were positively correlated with aridity. The relative abundances of Ephedra increased from meadow steppe to typical steppe and desert steppe. Tamarix and Zygophyllaceae were found in both typical steppe and desert steppe, but not in meadow steppe. Nitraria was only found in desert steppe. The relative abundances of xerophilous elements were greater in desert steppe than in typical steppe. These findings indicate that Eurasian steppe types can be differentiated based on recent pollen rain.


Asunto(s)
Ecosistema , Pradera , Polen , China , Humedad , Mongolia , Temperatura
19.
PLoS One ; 9(4): e94572, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24740144

RESUMEN

A melissopalynological analysis of fifty-one natural honey samples (twenty four spring, fifteen summer and twelve winter) collected during 2010-2011 from two east-coastal districts (20(0)20/ to 22(0)11/ N, 82(0)39/ to 87(0)01/ E) of Orissa, India was performed. Out of 37 unifloral samples found 25 were contributed by Apis cerana indica, seven by A. dorsata and the remaining five by A. florea. Out of 14 multifloral samples five were contributed by A. cerana indica, five by A. dorsata and the remaining four by A. florea. Principal component analysis confirmed the palynological classification of the unifloral honey samples. Eighty-two bee-plant taxa belonging to forty four families were recovered. The predominant nectariferous taxa of the spring season were Acanthus ilicifolius, Avicennia marina, Bruguiera gymnorrhiza, Cocos nucifera, Eucalyptus globulus, Phoenix paludosa, Pongamia pinnata, Prosopis juliflora, Sonneratia apetala and Syzygium cumini. In the summer the predominant nectariferous taxa were Borassus flabellifer, C. nucifera, E. globulus, Syzygium cumini, Terminalia arjuna, Aegiceras corniculatum, P. paludosa and Sonneratia apetala while those of the winter were Brassica nigra, Coriandrum sativum, Zizyphus jujuba, Alstonia scholaris, E. globulus and Bruguiera gymnorrhiza. Very low (<0.09) HDE/P for 98% of the samples and absence of toxic palynotaxa assure that these honeys are suitable for human consumption. Quite extended honey flow period with spring and summer as best forage seasons for the honeybees and occurrence of 82% of these honeys with APC Group II, III and IV justify the sustainability of the present study area for establishing moderate to large-scale apicultural entrepreneurship. This should improve the socio-economic status of the people of this region.


Asunto(s)
Apicultura/métodos , Abejas/fisiología , Emprendimiento/estadística & datos numéricos , Miel/análisis , Animales , Apicultura/economía , Abejas/clasificación , Recuento de Células , Emprendimiento/economía , Geografía , Humanos , India , Magnoliopsida/clasificación , Magnoliopsida/citología , Polen/citología , Análisis de Componente Principal , Estaciones del Año , Especificidad de la Especie
20.
PLoS One ; 7(6): e39780, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22761901

RESUMEN

It is demonstrated that palynomorphs can occur in fired ancient potsherds when the firing temperature was under 350°C. Pollen and phytoliths recovered from incompletely fired and fully fired potsherds (ca. 2700 yrs BP) from the Yanghai Tombs, Turpan, Xinjiang, NW China can be used as potential indicators for reconstructing past vegetation and corresponding climate in the area. The results show a higher rate of recovery of pollen and phytoliths from incompletely fired potsherds than from fully fired ones. Charred phytoliths recovered from both fully fired and incompletely fired potsherds prove that degree and condition of firing result in a permanent change in phytolith color. The palynological data, together with previous data of macrobotanical remains from the Yanghai Tombs, suggest that temperate vegetation and arid climatic conditions dominated in the area ca. 2700 yrs BP.


Asunto(s)
Clima , Fósiles , Plantas , Polen , China
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...