The utilization of palynological data for plant diversity reconstructions offers notable advantages in addressing the discontinuity of plant fossils in the stratigraphic record. However, additional studies of modern p...The utilization of palynological data for plant diversity reconstructions offers notable advantages in addressing the discontinuity of plant fossils in the stratigraphic record. However, additional studies of modern processes are required to validate or refine the accuracy of diversity results obtained from palynological data. In this study, we used a modern pollen dataset of China to compare the accuracy of plant diversity reconstructions using five different palynological diversity indices(i.e., the pollen species number, Berger-Parker index, Simpson diversity index, Hill index, and Shannon-Wiener index) over a large spatial scale. We then identified climate factors that are most strongly correlated with these patterns of plant diversity. We found that the index that most accurately reflects plant diversity is the Shannon-Wiener index. Our analyses indicated that the most effective indices at reflecting plant diversity are the Shannon-Wiener index and Berger-Parker index. Numerical analysis revealed that palynological diversity(measured using the Shannon-Wiener index) was strongly correlated with climatic parameters, in particular average temperature in the coldest month and annual precipitation,suggesting these factors may be primary determinants of plant diversity distribution. We also found that a threshold value of the normalized Shannon-Wiener index(NH = 0.4) approximately aligns with the contour line specifying 400 mm annual precipitation, serving as a rudimentary indicator for assessing plant diversity in arid versus humid climates. This study suggests that pollen diversity indices have remarkable potential for quantitatively reconstructing paleoclimatic parameters.展开更多
Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation,extinction,and dispersal have influenced current distributions.Here...Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation,extinction,and dispersal have influenced current distributions.Here,we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across the world.We identify centers of paleo-endemism and neo-endemism of angiosperm genera,and show that they are mostly located in the Southern Hemisphere in tropical and subtropical regions,particularly in Asia and Australia.Different categories of phylogenetic endemism centers can be differentiated using current climate conditions.Current climate,historical climate change,and geographic variables together explained~80%of global variation in taxonomic and phylogenetic endemism,while 42-46%,1%,and 15%were independently explained by these three types of variables,respectively.Thus our findings show that past climate change,current climate,and geography act together in shaping endemism,which are consistent with the findings of previous studies that higher temperature and topographic heterogeneity promote endemism.Our study showed that many centers of phylogenetic endemism of angiosperms,including regions in Amazonia,Venezuela,and west-central tropical Africa that have not previously been identified as biodiversity hotspots,are missed by taxon-based measures of endemism,indicating the importance of including evolutionary history in biodiversity assessment.展开更多
The protective role of xanthophyll cycle in resurrection angiosperm Boea hygrometrica (Bunge) R.Br. was investigated by analysis of the changes of chlorophyll fluorescence and xanthophyll cycle components in response ...The protective role of xanthophyll cycle in resurrection angiosperm Boea hygrometrica (Bunge) R.Br. was investigated by analysis of the changes of chlorophyll fluorescence and xanthophyll cycle components in response to dehydration and rehydration in detached leaves under very weak light condition (3 mumol photons.m(-2).s(-1)) and in the dark. With declines in the values of PSII photochemical efficiency (Fv/Fm), PSII actual quantum yield (Phi(PSII)), photochemical quenching (qP) and non-photochemical quenching (NPQ) during dehydration, zeaxanthin significantly increased in control Boea leaves under very weak light condition, while no zeaxanthin accumulation was detected in Boea leaves treated with dithiothreitol (DTT) and Boea leaves in the dark, and after 3 d rehydration, the parameters Fv/Fm, Phi(PSII), qP and NPQ showed full recovery in control Boea leaves under very weak light condition, but the parameters only underwent partial recovery in Boea leaves treated with DTT and Boea leaves in the dark, suggesting that the recovery of photosystem II (PSII) photochemical activities in Boea leaves was obviously affected by treatments with DTT and darkness, therefore, zeaxanthin may play an important protective role in desiccated Boea leaves even under very weak light conditions.展开更多
Resurrection plants which are able to quickly reactivate after falling into a period of anabiosis caused by dehydration have been very rare among angiosperms, especially among dicotyledons whose chlorophyll content an...Resurrection plants which are able to quickly reactivate after falling into a period of anabiosis caused by dehydration have been very rare among angiosperms, especially among dicotyledons whose chlorophyll content and chloroplast structure little changed in the course of desiccation, therefore has been called homoiochlorophyllous desiccation-tolerant plants (HDTs). Another type of resurrection angiosperms that lost its chlorophyll dining desiccation is called poikilochlorophyllous desiccation-tolerant plants (PDTs). HDTs have been received more attention because of simplicity of protection mechanism which is much easy to the study and utilization of the desiccation tolerance of resurrection angiosperms. Recent advances in studies of photosynthesis of resurrection angiosperms indicate that photochemical activities are sensitive indicators for the study of physiological state of resurrection angiosperms during desiccation and rehydration. Photochemical activities of resurrection angiosperms are inhibited with loss of water similar to those of general plants, however, the magic thing is that they could reactivate rapidly during rehydration even losing more than 95% water. Up-regulations in xanthophyll cycle and antioxidative systems as well as preservation in integrity and stability of photosynthetic membranes during desiccation may be very important to desiccation tolerance of resurrection angiosperms. The fact that phosphate treatment in rehydration stage also strongly influences resurrection indicated importance of studies on rehydration stages of resurrection angiosperms.展开更多
This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction an...This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction and built up notable contributions to the flourish of this field. Keeping pace with international development and participating international cooperation in the field of IVF, Chinese scientists have now focused on the investigation of basic mechanism relevant to possible gamete interaction, egg cell activation and early embryogenesis by IVF. In vitro manipulation techniques are combined with cytological and molecular biological approaches to unveil the double fertilization mysteries.展开更多
The origin of angiosperms has been tantalizing botanists for centuries. Despite the efforts of palaeobotanists, most of the pre-Cretaceous angiosperms are regarded either non-convincing or misdated. The applications o...The origin of angiosperms has been tantalizing botanists for centuries. Despite the efforts of palaeobotanists, most of the pre-Cretaceous angiosperms are regarded either non-convincing or misdated. The applications of SEM and LM （light microscope） enable us to recognize a coalified fossil plant, Xingxueanthus sinensis gen. et sp. nov., from the Haifanggou Formation （Middle Jurassic, 〉160 Ma） in western Liaoning, China. Xingxueanthus is an ＂inflorescence＂ with more than 20 female units spirally arranged. Each female unit is situated in the axii of a bract. The female unit is composed of an ovule-container and a style-like projection at the top. There is a vertical column bearing several ovules in the ovule-container. The general morphology and the internal structure of Xingxueanthus distinguish itself from any known fossil and extant gymnosperms, and its structures are more comparable to those of angiosperms. Xingxueanthus, if taken as a gymnosperm, would represent a new class, demonstrate an evolutionarily advanced status of ovule-protection in gymnosperms never seen before, and provide new insights into the origin of angiospermy. Alternatively, if taken as an angiosperm, together with Schmeissneria, it would increase the diversity of Jurassic angiosperms, which has been underestimated for a long time, and suggest a much earlier origin of angiospermy than currently accepted.展开更多
Searching for early angiosperms is a riveting activity in botany because it helps to resolve the phyiogenetic relationships among seed plants and among angiosperms themselves. One of the challenges for this job is wha...Searching for early angiosperms is a riveting activity in botany because it helps to resolve the phyiogenetic relationships among seed plants and among angiosperms themselves. One of the challenges for this job is what the target fossils look like. Most possibly early angiosperms may elude our scrutiny with gymnospermous appearances. This possibility becomes a reality in a Jurassic plant, Solaranthus gen. nov, which bears a peltaspermalean appearance and enclosed ovules. According to knowledge available hitherto, the latter feature makes it an angiosperm. However, such a feature is more likely to be eclipsed by its gymnospermous appearance. The early age and unexpected character assemblage of Solaranthus urge for a fresh look on the assumed-simple relationship between angiosperms and gymnosperms. Its resemblance to the order Peltaspermales favors the Mostly Male Theory.展开更多
Three taxa of Late Cretaceous aquatic angiosperms, Queruexia angulata （Lesq.） Krysht., Cobbania corrugata （Lesq.） Stockey et al. and Nelumbites cf. extenuinervis Upchurch et al. from Jiayin of Heilongjiang, NE Chi...Three taxa of Late Cretaceous aquatic angiosperms, Queruexia angulata （Lesq.） Krysht., Cobbania corrugata （Lesq.） Stockey et al. and Nelumbites cf. extenuinervis Upchurch et al. from Jiayin of Heilongjiang, NE China, are described in detail. Among them, Cobbania and Nelumbites from the Upper Cretaceous in China are reported for the first time. The aquatic angiosperm assemblage of Queruexia-Cobbania-Nelumbites appears to imply a seasonal, warm and moist environment in the Jiayin area during the Santonian-Campanian time.展开更多
The remarkable transition of early angiosperms from a small to a dominant group characterized the terrestrial ecosystem of the Cretaceous. This transition was instigated and promoted by environmental changes. Mid-Cret...The remarkable transition of early angiosperms from a small to a dominant group characterized the terrestrial ecosystem of the Cretaceous. This transition was instigated and promoted by environmental changes. Mid-Cretaceous is characterized by major geological events that affected the global environment. δ^18O, palaeothermometer TEX86, and other climatic indices from marine sediments suggest rapid temperature increase during mid-Cretaceous despite occasional short cooling events. Simultaneously, terrestrial deposits in East Asia changed from coal-bearing to shale, then to red beds and evaporites. Plant assemblages and other paleoclimate indicators point to rapid aridification for midCretaceous terrestrial environments. In addition, the wildfires were frequently spread all over the earth by the numerous charcoal evidence during the Mid-Cretaceous. Thus, we speculate that the seasonally dry and hot conditions of mid-Cretaceous created a fiery hothouse world. Early angiosperms increased in abundance and diversity and evolved from a few aquatic species to terrestrial herbaceous and then to the diversified flora of today. Angiosperms showed rapid physiological evolution in vein density and leaf area that improved photosynthesis and water absorption. These ecophysiological changes made early angiosperms well adapted to the hot and dry environment in mid-Cretaceous. Moreover, these physiological changes facilitated the fire–angiosperm cycles in mid-Cretaceous that likely further stimulated the early angiosperm evolution.展开更多
The Yixian Formation（the Early Cretaceous） of China has yielded a diverse group of early angiosperms, revealing the charm of angiosperms from the formation is far from finishing. Here we report a fossil angiosperm, ...The Yixian Formation（the Early Cretaceous） of China has yielded a diverse group of early angiosperms, revealing the charm of angiosperms from the formation is far from finishing. Here we report a fossil angiosperm, Nothodichocarpum gen. et sp. nov, with physically connected female parts, male parts, branches, and leaves with pinnate reticulate venation from the Yixian Formation of Liaoning, China. In addition to the previous reports, this report underscores the diversity of angiosperms in the Early Cretaceous Yixian Formation and earlier origin of angiosperms. The morphological variations in the reproductive parts in different stages allow us to infer the development of this early angiosperm. This fossil plant demonstrates a unique character assemblage that sheds new light on the origin and evolution of carpels.展开更多
In contrast to woody habit with secondary growth, truthful herbaceous habit lacking secondary growth is restricted to angiosperms among seed plants. Although angiosperms might have occurred as early as in the Triassic...In contrast to woody habit with secondary growth, truthful herbaceous habit lacking secondary growth is restricted to angiosperms among seed plants. Although angiosperms might have occurred as early as in the Triassic and herbaceous habit theoretically may have been well adopted by pioneer angiosperms, pre-Cretaceous herbs are missing hitherto, leaving the origin of herbs and evolution of herbaceous angiosperms mysterious. Here we report Juraherba bodae gen. et sp. nov, a whole plant herbaceous angiosperm, from the Middle Jurassic （〉164 Ma） at Daohugou Village, Inner Mongolia, China, a fossil Lagerst^itten that is worldwide famous for various fossil finds. The angiospermous affinity of Juraherba is ensured by its enclosed ovules/seeds. The plant is small but complete, with physically connected hairy root, stem, leaves, and fructifications. The Middle Jurassic age recommends Juraherba as the earliest record of herbaceous seed plants, demanding a refresh look at the evolutionary history of angiosperms.展开更多
The Yixian Formation （Lower Cretaceous） of China is famous for its fossils of early angiosperms, and these fossils have shed otherwise unavailable light on the evolution of angiosperms. The seeds in Archaefructus an...The Yixian Formation （Lower Cretaceous） of China is famous for its fossils of early angiosperms, and these fossils have shed otherwise unavailable light on the evolution of angiosperms. The seeds in Archaefructus and Nothodichocarpum are inserted along the dorsal of the fruits while those in Sinocarpus are along the ventral of the fruits, suggesting different Bau-plans and pathways deriving the carpels in these plants of the Early Cretaceous. Adding further fossil evidence, here we report a novel fossil angiosperm, Neofructus lingyuanensis gen. et sp. nov, with its seeds inserted on both ventral and dorsal sides of the fruits documented through light microscopic and SEM observations, suggesting a novel way forming gynoecium in the Yixian Formation. These fossil angiosperms indicate that angiosperm gynoecia in the Yixian Formation （the Barremian to Aptian） are derived in obviously different ways, implying an evolutionary scenario for angiosperms quite different from formerly assumed.展开更多
Beta diversity(β-diversity)is the scalar between local(α)and regional(γ)diversity.Understanding geographic patterns ofβ-diversity is central to ecology,biogeography,and conservation biology.A full understanding of...Beta diversity(β-diversity)is the scalar between local(α)and regional(γ)diversity.Understanding geographic patterns ofβ-diversity is central to ecology,biogeography,and conservation biology.A full understanding of the origin and maintenance of geographic patterns ofβ-diversity requires exploring both taxonomic and phylogeneticβ-diversity,as well as their respective turnover and nestedness components,and exploring phylogenetic p-diversity at different evolutionary depths.In this study,we explore and map geographic patterns ofβ-diversity for angiosperm genera in regional floras across the world.We examine both taxonomic and phylogeneticβ-diversity and their constituent components,and both tip-weighted and basal-weighted phylogeneticβ-diversity,and relate them to latitude.On the one hand,our study found that the global distribution ofβ-diversity is highly heterogeneous.This is the case for both taxonomic and phylogeneticβ-diversity,and for both tip-weighted and basal-weighted phylogeneticβ-diversity.On the other hand,our study found that there are highly consistent geographic patterns among different metrics ofβ-diversity.In most cases,metrics ofβ-diversity are negatively associated with latitude,particularly in the Northern Hemisphere.Different metrics of taxonomicβ-diversity are strongly and positively correlated with their counterparts of phylogeneticβ-diversity.展开更多
基金co-supported by the National Key Research and Development Program of China(2022YFF0800800)the National Natural Science Foundation of China(41988101-01,42130205)the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0707)。
文摘The utilization of palynological data for plant diversity reconstructions offers notable advantages in addressing the discontinuity of plant fossils in the stratigraphic record. However, additional studies of modern processes are required to validate or refine the accuracy of diversity results obtained from palynological data. In this study, we used a modern pollen dataset of China to compare the accuracy of plant diversity reconstructions using five different palynological diversity indices(i.e., the pollen species number, Berger-Parker index, Simpson diversity index, Hill index, and Shannon-Wiener index) over a large spatial scale. We then identified climate factors that are most strongly correlated with these patterns of plant diversity. We found that the index that most accurately reflects plant diversity is the Shannon-Wiener index. Our analyses indicated that the most effective indices at reflecting plant diversity are the Shannon-Wiener index and Berger-Parker index. Numerical analysis revealed that palynological diversity(measured using the Shannon-Wiener index) was strongly correlated with climatic parameters, in particular average temperature in the coldest month and annual precipitation,suggesting these factors may be primary determinants of plant diversity distribution. We also found that a threshold value of the normalized Shannon-Wiener index(NH = 0.4) approximately aligns with the contour line specifying 400 mm annual precipitation, serving as a rudimentary indicator for assessing plant diversity in arid versus humid climates. This study suggests that pollen diversity indices have remarkable potential for quantitatively reconstructing paleoclimatic parameters.
文摘Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation,extinction,and dispersal have influenced current distributions.Here,we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across the world.We identify centers of paleo-endemism and neo-endemism of angiosperm genera,and show that they are mostly located in the Southern Hemisphere in tropical and subtropical regions,particularly in Asia and Australia.Different categories of phylogenetic endemism centers can be differentiated using current climate conditions.Current climate,historical climate change,and geographic variables together explained~80%of global variation in taxonomic and phylogenetic endemism,while 42-46%,1%,and 15%were independently explained by these three types of variables,respectively.Thus our findings show that past climate change,current climate,and geography act together in shaping endemism,which are consistent with the findings of previous studies that higher temperature and topographic heterogeneity promote endemism.Our study showed that many centers of phylogenetic endemism of angiosperms,including regions in Amazonia,Venezuela,and west-central tropical Africa that have not previously been identified as biodiversity hotspots,are missed by taxon-based measures of endemism,indicating the importance of including evolutionary history in biodiversity assessment.
文摘The protective role of xanthophyll cycle in resurrection angiosperm Boea hygrometrica (Bunge) R.Br. was investigated by analysis of the changes of chlorophyll fluorescence and xanthophyll cycle components in response to dehydration and rehydration in detached leaves under very weak light condition (3 mumol photons.m(-2).s(-1)) and in the dark. With declines in the values of PSII photochemical efficiency (Fv/Fm), PSII actual quantum yield (Phi(PSII)), photochemical quenching (qP) and non-photochemical quenching (NPQ) during dehydration, zeaxanthin significantly increased in control Boea leaves under very weak light condition, while no zeaxanthin accumulation was detected in Boea leaves treated with dithiothreitol (DTT) and Boea leaves in the dark, and after 3 d rehydration, the parameters Fv/Fm, Phi(PSII), qP and NPQ showed full recovery in control Boea leaves under very weak light condition, but the parameters only underwent partial recovery in Boea leaves treated with DTT and Boea leaves in the dark, suggesting that the recovery of photosystem II (PSII) photochemical activities in Boea leaves was obviously affected by treatments with DTT and darkness, therefore, zeaxanthin may play an important protective role in desiccated Boea leaves even under very weak light conditions.
文摘Resurrection plants which are able to quickly reactivate after falling into a period of anabiosis caused by dehydration have been very rare among angiosperms, especially among dicotyledons whose chlorophyll content and chloroplast structure little changed in the course of desiccation, therefore has been called homoiochlorophyllous desiccation-tolerant plants (HDTs). Another type of resurrection angiosperms that lost its chlorophyll dining desiccation is called poikilochlorophyllous desiccation-tolerant plants (PDTs). HDTs have been received more attention because of simplicity of protection mechanism which is much easy to the study and utilization of the desiccation tolerance of resurrection angiosperms. Recent advances in studies of photosynthesis of resurrection angiosperms indicate that photochemical activities are sensitive indicators for the study of physiological state of resurrection angiosperms during desiccation and rehydration. Photochemical activities of resurrection angiosperms are inhibited with loss of water similar to those of general plants, however, the magic thing is that they could reactivate rapidly during rehydration even losing more than 95% water. Up-regulations in xanthophyll cycle and antioxidative systems as well as preservation in integrity and stability of photosynthetic membranes during desiccation may be very important to desiccation tolerance of resurrection angiosperms. The fact that phosphate treatment in rehydration stage also strongly influences resurrection indicated importance of studies on rehydration stages of resurrection angiosperms.
文摘This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction and built up notable contributions to the flourish of this field. Keeping pace with international development and participating international cooperation in the field of IVF, Chinese scientists have now focused on the investigation of basic mechanism relevant to possible gamete interaction, egg cell activation and early embryogenesis by IVF. In vitro manipulation techniques are combined with cytological and molecular biological approaches to unveil the double fertilization mysteries.
基金supported by National Natural Science Foundation of China Programs (No. 40772006, 30670140, 40372008, 40632010 and J0630967),the State Key Laboratory of Systematic and Evolutionary Botany at the Institute of Botany, and SRF for ROCS, SEM
文摘The origin of angiosperms has been tantalizing botanists for centuries. Despite the efforts of palaeobotanists, most of the pre-Cretaceous angiosperms are regarded either non-convincing or misdated. The applications of SEM and LM （light microscope） enable us to recognize a coalified fossil plant, Xingxueanthus sinensis gen. et sp. nov., from the Haifanggou Formation （Middle Jurassic, 〉160 Ma） in western Liaoning, China. Xingxueanthus is an ＂inflorescence＂ with more than 20 female units spirally arranged. Each female unit is situated in the axii of a bract. The female unit is composed of an ovule-container and a style-like projection at the top. There is a vertical column bearing several ovules in the ovule-container. The general morphology and the internal structure of Xingxueanthus distinguish itself from any known fossil and extant gymnosperms, and its structures are more comparable to those of angiosperms. Xingxueanthus, if taken as a gymnosperm, would represent a new class, demonstrate an evolutionarily advanced status of ovule-protection in gymnosperms never seen before, and provide new insights into the origin of angiospermy. Alternatively, if taken as an angiosperm, together with Schmeissneria, it would increase the diversity of Jurassic angiosperms, which has been underestimated for a long time, and suggest a much earlier origin of angiospermy than currently accepted.
基金supported by NSFC Programs (No.40772006,40372008,40632010 and J0630967)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Searching for early angiosperms is a riveting activity in botany because it helps to resolve the phyiogenetic relationships among seed plants and among angiosperms themselves. One of the challenges for this job is what the target fossils look like. Most possibly early angiosperms may elude our scrutiny with gymnospermous appearances. This possibility becomes a reality in a Jurassic plant, Solaranthus gen. nov, which bears a peltaspermalean appearance and enclosed ovules. According to knowledge available hitherto, the latter feature makes it an angiosperm. However, such a feature is more likely to be eclipsed by its gymnospermous appearance. The early age and unexpected character assemblage of Solaranthus urge for a fresh look on the assumed-simple relationship between angiosperms and gymnosperms. Its resemblance to the order Peltaspermales favors the Mostly Male Theory.
基金supported by the NSFC(Nos.302213069830379500+2 种基金40842002)the Foundation of Jilin University(No.602257)The study was also partially financed by the Bureau of Land and Resources of Heilongjiang(2005-2006)
文摘Three taxa of Late Cretaceous aquatic angiosperms, Queruexia angulata （Lesq.） Krysht., Cobbania corrugata （Lesq.） Stockey et al. and Nelumbites cf. extenuinervis Upchurch et al. from Jiayin of Heilongjiang, NE China, are described in detail. Among them, Cobbania and Nelumbites from the Upper Cretaceous in China are reported for the first time. The aquatic angiosperm assemblage of Queruexia-Cobbania-Nelumbites appears to imply a seasonal, warm and moist environment in the Jiayin area during the Santonian-Campanian time.
基金supported by the National Natural Science Foundation of China(No.41602023,41402007)the Key Laboratory Project of Gansu Province(Grant No.1309RTSA041)
文摘The remarkable transition of early angiosperms from a small to a dominant group characterized the terrestrial ecosystem of the Cretaceous. This transition was instigated and promoted by environmental changes. Mid-Cretaceous is characterized by major geological events that affected the global environment. δ^18O, palaeothermometer TEX86, and other climatic indices from marine sediments suggest rapid temperature increase during mid-Cretaceous despite occasional short cooling events. Simultaneously, terrestrial deposits in East Asia changed from coal-bearing to shale, then to red beds and evaporites. Plant assemblages and other paleoclimate indicators point to rapid aridification for midCretaceous terrestrial environments. In addition, the wildfires were frequently spread all over the earth by the numerous charcoal evidence during the Mid-Cretaceous. Thus, we speculate that the seasonally dry and hot conditions of mid-Cretaceous created a fiery hothouse world. Early angiosperms increased in abundance and diversity and evolved from a few aquatic species to terrestrial herbaceous and then to the diversified flora of today. Angiosperms showed rapid physiological evolution in vein density and leaf area that improved photosynthesis and water absorption. These ecophysiological changes made early angiosperms well adapted to the hot and dry environment in mid-Cretaceous. Moreover, these physiological changes facilitated the fire–angiosperm cycles in mid-Cretaceous that likely further stimulated the early angiosperm evolution.
基金supported by the National Natural Science Foundation of China (41688103,91514302,91114201) awarded to X.W.State Forestry Administration of China (No.2005–122)+1 种基金Science and Technology Project of Guangdong (No.2011B060400011)Special Funds for Environmental Projects of Shenzhen (No.2013-02) awarded to Z.J.L.
文摘The Yixian Formation（the Early Cretaceous） of China has yielded a diverse group of early angiosperms, revealing the charm of angiosperms from the formation is far from finishing. Here we report a fossil angiosperm, Nothodichocarpum gen. et sp. nov, with physically connected female parts, male parts, branches, and leaves with pinnate reticulate venation from the Yixian Formation of Liaoning, China. In addition to the previous reports, this report underscores the diversity of angiosperms in the Early Cretaceous Yixian Formation and earlier origin of angiosperms. The morphological variations in the reproductive parts in different stages allow us to infer the development of this early angiosperm. This fossil plant demonstrates a unique character assemblage that sheds new light on the origin and evolution of carpels.
基金supported by the National Basic Research Program of China(973 Program 2012CB821901)Team Program of Scientific Innovation and Interdisciplinary Cooperation,Chinese Academy of Sciences(2013-2015)+3 种基金National Natural Science Foundation of China (91114201,41172006) awarded to X.WState Forestry Administration of China(No.2005-122)Science and Technology Project of Guangdong(No. 2011B060400011)Special Funds for Environmental Projects of Shenzhen(No.2013-02) awarded to Z.J.L.
文摘In contrast to woody habit with secondary growth, truthful herbaceous habit lacking secondary growth is restricted to angiosperms among seed plants. Although angiosperms might have occurred as early as in the Triassic and herbaceous habit theoretically may have been well adopted by pioneer angiosperms, pre-Cretaceous herbs are missing hitherto, leaving the origin of herbs and evolution of herbaceous angiosperms mysterious. Here we report Juraherba bodae gen. et sp. nov, a whole plant herbaceous angiosperm, from the Middle Jurassic （〉164 Ma） at Daohugou Village, Inner Mongolia, China, a fossil Lagerst^itten that is worldwide famous for various fossil finds. The angiospermous affinity of Juraherba is ensured by its enclosed ovules/seeds. The plant is small but complete, with physically connected hairy root, stem, leaves, and fructifications. The Middle Jurassic age recommends Juraherba as the earliest record of herbaceous seed plants, demanding a refresh look at the evolutionary history of angiosperms.
基金supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences(XDB26000000)National Natural Science Foundation of China (91514302, 91114201) awarded to X.W.+2 种基金State Forestry Administration of China (No. 2005–122)Science and Technology Project of Guangdong (No. 2011B060400011)Special Funds for Environmental Projects of Shenzhen (No. 2013-02) awarded to Z. J. L.
文摘The Yixian Formation （Lower Cretaceous） of China is famous for its fossils of early angiosperms, and these fossils have shed otherwise unavailable light on the evolution of angiosperms. The seeds in Archaefructus and Nothodichocarpum are inserted along the dorsal of the fruits while those in Sinocarpus are along the ventral of the fruits, suggesting different Bau-plans and pathways deriving the carpels in these plants of the Early Cretaceous. Adding further fossil evidence, here we report a novel fossil angiosperm, Neofructus lingyuanensis gen. et sp. nov, with its seeds inserted on both ventral and dorsal sides of the fruits documented through light microscopic and SEM observations, suggesting a novel way forming gynoecium in the Yixian Formation. These fossil angiosperms indicate that angiosperm gynoecia in the Yixian Formation （the Barremian to Aptian） are derived in obviously different ways, implying an evolutionary scenario for angiosperms quite different from formerly assumed.
文摘Beta diversity(β-diversity)is the scalar between local(α)and regional(γ)diversity.Understanding geographic patterns ofβ-diversity is central to ecology,biogeography,and conservation biology.A full understanding of the origin and maintenance of geographic patterns ofβ-diversity requires exploring both taxonomic and phylogeneticβ-diversity,as well as their respective turnover and nestedness components,and exploring phylogenetic p-diversity at different evolutionary depths.In this study,we explore and map geographic patterns ofβ-diversity for angiosperm genera in regional floras across the world.We examine both taxonomic and phylogeneticβ-diversity and their constituent components,and both tip-weighted and basal-weighted phylogeneticβ-diversity,and relate them to latitude.On the one hand,our study found that the global distribution ofβ-diversity is highly heterogeneous.This is the case for both taxonomic and phylogeneticβ-diversity,and for both tip-weighted and basal-weighted phylogeneticβ-diversity.On the other hand,our study found that there are highly consistent geographic patterns among different metrics ofβ-diversity.In most cases,metrics ofβ-diversity are negatively associated with latitude,particularly in the Northern Hemisphere.Different metrics of taxonomicβ-diversity are strongly and positively correlated with their counterparts of phylogeneticβ-diversity.
