Angiosperm Diversification Research Articles

Diversity of angiosperms and their conservation status in Susunia hill and adjacent regions, Bankura District, West Bengal, India

Angiosperms are the most important group among the plant kingdom. An attempt was made to study the angiosperms diversity and their conservation status of Susunia hill and its adjacent region in Bankura district, West Bengal. The plants were collected from the study area and identified. Field survey method was used for the present investigation. The threatened, endangered, not evaluated, least concern and vulnerable status of plant species were confirmed by India biodiversity portal and other standard publications on rare and threatened taxa of the country. A total of 91 species of angiosperms were recorded which were represented by 84 genera belonging to 42 different families. During the survey period 02 species of Pteridophytes under 02 genera belonging to 02 differerent families were also reported. Fabaceae was recorded as most dominant family from the angiosperms in study site. There were 36 species as least concern, 10 species as not evaluated, 04 species as vulnerable, 01 species as near threatened and 01 species as endangered as per the IUCN threatened categories. Analysis of habits showed that trees were represented by the highest proportion followed by perennial herbs, shrubs, annual herbs and climbers. The present study is the compilation of data on threatened plants of Susunia hill purview over various literatures with an update on their present status. It needs conservation of the biodiversity and their habitat as well as to increase the awareness of the people for the importance of the study site.

Diversity of angiosperms and their conservation status in BiharinathHill,Bankura,West Bengal,India

Diversity of angiosperms and their conservation status in BiharinathHill,Bankura,West Bengal,India

Angiosperm diversity in a Lowland Semideciduous Seasonal Forest in Pernambuco State, Brazil

Abstract: Angiosperm species growing in a fragment of Lowland Semideciduous Seasonal Forest in the Tapacurá Ecological Station (TES) in Pernambuco State (Brazil) were surveyed. Botanical collections to compose a species list were undertaken and these species identified by comparisons with specimens deposited in the HST, PEUFR and IPA herbaria, in addition to online database queries. A total of 479 species were identified, belonging to 81 families and 285 genera. The families with the largest numbers of species were Fabaceae (68), Rubiaceae (25), Malvaceae (20), Myrtaceae (20), Cyperaceae (19), Poaceae (19), Bromeliaceae (18), Euphorbiaceae (17), Asteraceae (16), and Sapindaceae (14), which together accounted for 49.27% of the total number of species. Great similarity was observed between our results and surveys of other lowland forests in northeastern Brazil, with the families Fabaceae, Rubiaceae, and Myrtaceae having the greatest species richness. This study added 44 new occurrences for Pernambuco State, demonstrating the richness and abundance of TES taxa and the importance of their conservation to the regional flora.

The Early Cretaceous mesofossil flora of Catefica, Portugal: angiosperms

Angiosperm mesofossils are described from the Lower Cretaceous Almargem Formation exposed near the village of Catefica, Portugal, and are thought to be of Aptian-early Albian age. The mesofossil assemblage from Catefica is diverse and, in addition to the angiosperms described here, also contains a rich assemblage of non-angiosperm fossils, including leafy axes of bryophytes and lycopsids, lycopsid and salvinialean megaspores, and sporangia, sori and leaf fragments of ferns. There are also twigs, cones, cone scales, seeds and sporangia of several kinds of conifers. Other seed plants include 11 species of chlamydospermous seeds and vegetative axes related to the BEG group (Bennettiales-Erdtmanithecales-Gnetales). In terms of the number of plant fragments identified, angiosperms are most abundant in the Catefica assemblage and account for more than half of all specimens. Angiosperms also dominate in number of species, but because the non-angiosperm fossils have not been studied in detail the total number of species in the flora is not yet established. Sixty-seven species of angiosperms are recognized. Angiosperm diversity is mainly at the level of non-eudicots, including ANA-grade angiosperms, Chloranthaceae and magnoliids. Remains of chloranthoid angiosperms are especially common, both in the number of specimens and in number of species recognized. About 40 % of the specimens, and more than 25 % of the species are chloranthoids. Remains of magnoliid angiosperms (Magnoliales, Laurales, Canellales, Piperales) are also prominent among the angiosperms. Eudicots are subordinate: only 3–4 % of all angiosperm specimens can be assigned confidently to eudicot angiosperms. Five new genera and six new species of angiosperms are established (Canrightia foveolata sp. nov., Elasmostemon paisii gen. et sp. nov., Endressistemon cateficensis gen. et sp. nov., Ibericarpus cuneiformis gen. et sp. nov., Proencistemon portugallicus gen. et sp. nov., Valvidistemon globiferus gen. et sp. nov.). Several other new taxa are also described, but not formally named.

Angiosperm Diversity in the Semiarid Region of Ceará State, Brazil, with Emphasis on Caatinga Species

Angiosperm Diversity in the Semiarid Region of Ceará State, Brazil, with Emphasis on Caatinga Species

Angiosperm affinities of Surangea from the late Cretaceous Deccan Intertrappean Beds of central India

The genus Surangea Chitaley et Sheikh, based on permineralized specimens from the Deccan Intertrappean Beds of central India, was originally considered to represent a fern megasporangium. Reexamination of original material and new specimens has revealed that the structures are capsular fruits with well-defined seeds, rather than megasporangia. We describe Surangea fruits in detail, based on peels and micro-CT scanning, and document its distribution among multiple localities of the Deccan Intertrappean Beds. The fruits are pentacarpellate septicidal capsules with ~8–12 seeds per locule. The seeds are prominently ornamented with parallel ridges and have a curved embryo/endosperm cavity and a prominent aril. This set of features indicates eudicotyledonous affinities for Surangea. In particular, the combination of septicidal capsules, axile placentation and arillate campylotropus seeds suggests affinity with the order Myrtales, but it does not fit cleanly within an extant family. Surangea fruits add to the diversity of angiosperms known from this late Maastrichtian flora. It joins several other fruit types known from the Deccan flora that do not fall neatly into extant families, possibly representing parts of an endemic community that succumbed to environmental stress associated K-Pg boundary events and/or subsequent northward rafting of the Indian subcontinent.

Temporal and spatial comparisons of angiosperm diversity between eastern Asia and North America.

Abstract Eastern Asia (EA) and North America north of Mexico (NA) have comparable latitude, land area, and climate, but the overall plant diversity is much higher in EA than in NA. Despite intensive studies on disjunct taxa of the two regions, the temporal and spatial diversity patterns between the two floras remain unclear. Here we explore the floristic differences between EA and NA using the well-studied floras of China and the United States of America (USA) as exemplars, while also employing a newly generated dated phylogeny covering ∼90% of the angiosperm genera of the two countries and comprehensive spatial distribution data. We find that China possesses both higher richness and phylogenetic diversity (PD) for angiosperm genera than the USA. Notably, most lineages contribute to the PD anomaly between the two floras, with 46 of 58 lineages having higher PD in China. Temporally, China has a higher proportion of genera that originated before the Miocene than found in the USA (29.9% vs 23.2%). The eastern USA has more genera that originated during the Paleogene than does the western USA, but the reverse pattern is observed after the middle Miocene, with more genera originating in the west. Spatially, China shows a more distinct east-west deviation in diversity than the USA with eastern China possessing much higher generic richness and PD and more ancient lineages than western China. However, the eastern USA possesses lower generic richness, but higher PD and more ancient lineages than the western USA. Both the floras in China and the USA share a signature of an older east and a younger west, and this pattern may be largely driven by regional orogenic activities and climatic changes in the west of the two regions. Finally, our study indicates that more efforts are needed to enhance biodiversity conservation in southern China and the eastern USA by identifying and protecting phylodiversity hotspots.

Chloranthus genome provides insights into the early diversification of angiosperms

Chloranthales remain the last major mesangiosperm lineage without a nuclear genome assembly. We therefore assemble a high-quality chromosome-level genome of Chloranthus spicatus to resolve enigmatic evolutionary relationships, as well as explore patterns of genome evolution among the major lineages of mesangiosperms (eudicots, monocots, magnoliids, Chloranthales, and Ceratophyllales). We find that synteny is highly conserved between genomic regions of Amborella, Vitis, and Chloranthus. We identify an ancient single whole-genome duplication (WGD) (κ) prior to the divergence of extant Chloranthales. Phylogenetic inference shows Chloranthales as sister to magnoliids. Furthermore, our analyses indicate that ancient hybridization may account for the incongruent phylogenetic placement of Chloranthales + magnoliids relative to monocots and eudicots in nuclear and chloroplast trees. Long genes and long introns are found to be prevalent in both Chloranthales and magnoliids compared to other angiosperms. Overall, our findings provide an improved context for understanding mesangiosperm relationships and evolution and contribute a valuable genomic resource for future investigations.

Pathogen-driven coevolution across the CBP60 plant immune regulator subfamilies confers resilience on the regulator module.

Components of the plant immune signaling network need mechanisms that confer resilience against fast-evolving pathogen effectors that target them. Among eight Arabidopsis CaM-Binding Protein (CBP) 60 family members, AtCBP60g and AtSARD1 are partially functionally redundant, major positive immune regulators, and AtCBP60a is a negative immune regulator. We investigated possible resilience-conferring evolutionary mechanisms among the CBP60a, CBP60g and SARD1 immune regulatory subfamilies. Phylogenetic analysis was used to investigate the times of CBP60 subfamily neofunctionalization. Then, using the pairwise distance rank based on the newly developed analytical platform Protein Evolution Analysis in a Euclidean Space (PEAES), hypotheses of specific coevolutionary mechanisms that could confer resilience on the regulator module were tested. The immune regulator subfamilies diversified around the time of angiosperm divergence and have been evolving very quickly. We detected significant coevolutionary interactions across the immune regulator subfamilies in all of 12 diverse core eudicot species lineages tested. The coevolutionary interactions were consistent with the hypothesized coevolution mechanisms. Despite their unusually fast evolution, members across the CBP60 immune regulator subfamilies have influenced the evolution of each other long after their diversification in a way that could confer resilience on the immune regulator module against fast-evolving pathogen effectors.

Development and regeneration of wheat-rice hybrid zygotes produced by in vitro fertilization system.

Summary Hybridization plays a decisive role in the evolution and diversification of angiosperms. However, the mechanisms of wide hybridization remain open because pre‐ and post‐fertilization barriers limit the production and development of inter‐subfamily/intergeneric zygotes, respectively.We examined hybridization between wheat and rice using an in vitro fertilization (IVF) system to bypass these barriers. Several gamete combinations of allopolyploid wheat–rice hybrid zygotes were successfully produced, and the developmental profiles of hybrid zygotes were analyzed.Hybrid zygotes derived from one rice egg cell and one wheat sperm cell ceased at the multicellular embryo‐like structure stage. This developmental barrier was overcome by adding one wheat egg cell to the wheat–rice hybrid zygote. In the reciprocal combination, one wheat egg and one rice sperm cell, the resulting hybrid zygotes failed to divide. However, doubling the dosage of rice sperm cell allowed the hybrid zygotes to develop into plantlets. Rice chromosomes appeared to be progressively eliminated during the early developmental stage of these hybrid embryos, and c. 20% of regenerated plants showed abnormal morphology.These results suggest that hybrid breakdown can be overcome through optimization of gamete combinations, and the present hybrid will provide a new horizon for utilization of inter‐subfamily genetic resources.

Early Cretaceous mealybug herbivory on a laurel highlights the deep-time history of angiosperm-scale insect associations.

Insect fluid-feeding on fossil vascular plants is an inconspicuous and underappreciated mode of herbivory that can provide novel data on the evolution of deep-time ecological associations and indicate the host-plant preferences of ancient insect herbivores. Previous fossil studies have documented piercing-and-sucking herbivory but often are unable to identify culprit insect taxa. One line of evidence are punctures and scale-insect impression marks made by piercing-and-sucking insects that occasionally provide clues to the systematic identities and relationships of particular insect herbivores. We report here the earliest occurrences of piercing and sucking on early angiosperms as evidenced by scale insect covers, impression marks, punctures and body fossils - notably a mealybug - from the Lower Cretaceous Rose Creek Flora of the Dakota Formation (c. 103Ma), in southeastern Nebraska, USA. The mealybug, two other scale insect taxa, and several distinctive damage types on laurel leaves and seed-plant stems at Rose Creek document a diverse guild of piercing-and-sucking insects on early angiosperms. The discovery of an Early Cretaceous female mealybug indicates an early herbivorous association with a laurel host. These data provide direct evidence for co-associations and possible coevolution of scale insects and their plant hosts during early angiosperm diversification.

Why More Leaflets? The Role of Natural Selection in Shaping the Spatial Pattern of Leaf-Shape Variation in Oxytropis diversifolia (Fabaceae) and Two Close Relatives.

Leaf shape exhibits tremendous diversity in angiosperms. It has long been argued that leaf shape can affect major physiological and ecological properties of plants and thus is likely to be adaptive, but the evolutionary evidence is still scarce. Oxytropis diversifolia (Fabaceae) is polymorphic for leaf shape (1 leaflet, 1–3 leaflets, and 3 leaflets) and exhibits clinal variation in steppes of Nei Mongol, China. With two close relatives predominantly fixed for one phenotype as comparison (Oxytropis neimonggolica with 1 leaflet and Oxytropis leptophylla with 5–13 leaflets), we used a comprehensive cline-fitting approach to assess the role of natural selection in shaping the spatial pattern of leaf-shape variation in this system. For 551 individuals sampled from 22 populations, we quantified leaf-morphological differentiation, evaluated patterns of neutral genetic variation using five chloroplast DNA intergenic regions and 11 nuclear microsatellite loci, and performed microhabitat and macroclimatic-association analyses. We found that 1-leaflet proportions in O. diversifolia populations significantly increased from west to east, and three phenotypes also differed in leaflet-blade size. However, compared with the other two species, populations of O. diversifolia showed little neutral genetic differentiation, and no population structure was detected at either marker. We further revealed that the leaf-shape cline could largely be explained by three macroclimatic variables, with leaflet number decreasing and leaflet-blade size increasing with annual precipitation and showing the reverse trends with temperature seasonality and isothermality. Our results suggest that spatially varying abiotic environmental factors contribute to shape the leaf-shape cline in O. diversifolia, while the interspecific pattern may be due to both local adaptation and historical events.

Diversity of Angiosperm Taxa in Chaar Khidirpur Area of Rajshahi, Bangladesh

Purpose: The aims to investigate the angiosperm taxa in the study area. The present research also documented the species diversity and important medicinal plants. Subjects and Methods: Angiosperm flora in the Chaar Khidirpur area of Rajshahi, Bangladesh was carried out from November 2018 to October 2019 to cover the seasonal variations. Plant parts with either flower or fruits collected using traditional herbarium techniques to make voucher specimens for documentation. Results: The result focused that a total of 210 species belonging to177 genera under 71 families were recorded. Forty-five (45) medicinal plants were used for the treatment of more than 61 diseases. Conclusion: The present study was the first time to report angiosperm diversity and medicinal plants in the study area. In this research, the status of occurrence has been recorded for proper conservation management and sustainable utilization of the taxa resulting in 81.33% being common, 16.74% as rare and 1.91% are found as threatened in the study area.

Patterns and drivers of phylogenetic structure of pteridophytes in China

AbstractAimPrevious studies have found strikingly different geographical patterns of phylogenetic diversity of gymnosperms and angiosperms, which have been suggested to result, in part, from the greater age of the former. To assess the effects of clade age on phylogenetic structure, we assessed phylodiversity patterns of pteridophytes (lycophytes and ferns), which combine ancient and modern lineages, across China.LocationChina.Time periodPresent day.TaxonPteridophytes.MethodsWe divided China into 66 regions and collated species lists of pteridophytes for each region. We then related taxonomic and phylogenetic diversity, and their related metrics, to six climatic variables for pteridophytes as a whole and for different evolutionary clades. We examined the effect of spatial autocorrelation among regional floras on the results.ResultsWe found that when all pteridophytes or ferns were considered, the patterns resembled those of gymnosperms, presumably reflecting the effects of several ancient global mass extinctions and the relict distribution of old families. In contrast, when we considered only the modern Polypodiales radiation, which accounts for three‐quarters of current fern diversity and is about as old as the angiosperm radiation, we found a pattern similar to that of angiosperms. This pattern is consistent with the tropical niche conservatism hypothesis and suggests that both major groups of land plants have a broadly similar evolutionary trajectory, with most families originating in tropical conditions and few families adapting to cold and arid conditions.Main conclusionsOur study shows that the phylogenetic structures of more recently evolved and diversified clades of pteridophytes are fairly consistent with the tropical niche conservatism hypothesis, suggesting that the age of the taxon, its physiological adaptations and the global climatic changes that it experienced during its evolutionary history are reflected in the composition of current plant assemblages.

Phylogenetics and comparative plastome genomics of two of the largest genera of angiosperms, Piper and Peperomia (Piperaceae)

Biological radiations provide unique opportunities to understand the evolution of biodiversity. One such radiation is the pepper plant family Piperaceae, an early-diverging and mega-diverse lineage that could serve as a model to study the diversification of angiosperms. However, traditional genetic markers lack sufficient variation for such studies, and testing hypotheses on poorly resolved phylogenetic frameworks becomes challenging. Limited genomic data is available for Piperaceae, which contains two of the largest genera of angiosperms, Piper (>2100 species) and Peperomia (>1300 species). To address this gap, we used genome skimming to assemble and annotate whole plastomes (152–161kbp) and >5kbp nuclear ribosomal DNA region from representatives of Piper and Peperomia. We conducted phylogenetic and comparative genomic analyses to study plastome evolution and investigate the role of hybridization in this group. Plastome phylogenetic trees were well resolved and highly supported, with a hard incongruence observed between plastome and nuclear phylogenetic trees suggesting hybridization in Piper. While all plastomes of Piper and Peperomia had the same gene content and order, there were informative structural differences between them. First, ycf1 was more variable and longer in Piper than Peperomia, extending well into the small single copy region by thousands of base pairs. We also discovered previously unknown structural variation in 14 out of 25 Piper taxa, tandem duplication of the trnH-GUG gene resulting in an expanded large single copy region. Other early-diverging angiosperms have a duplicated trnH-GUG, but the specific rearrangement we found is unique to Piper and serves to refine knowledge of relationships among early-diverging angiosperms. Our study demonstrates that genome skimming is an efficient approach to produce plastome assemblies for comparative genomics and robust phylogenies of species-rich plant genera.

Fruit evolution in Hydrophyllaceae.

Fruit type and morphology are tightly connected with angiosperm diversification. In Boraginales, the first-branching families, including Hydrophyllaceae, have one- to many-seeded capsules, whereas most of the remaining families have four-seeded indehiscent fruits. This fact argues for many-seeded capsules as the ancestral condition. However, little is known about the evolution of fruit dehiscence and seed number. The present study investigated the gynoecium and fruit development and morphology and the evolution of seed-numbers in Hydrophyllaceae. Gynoecium and fruit development and morphology were studied using scanning electron microscopy and x-ray microcomputed tomography. Ancestral character state reconstruction of seed number was performed using a broadly sampled phylogeny of Boraginales (ndhF and ITS) with an emphasis on Hydrophyllaceae. Our ontogenetic studies not only demonstrate parallel developmental trajectories across Hydrophyllaceae, but also a striking diversity regarding the internal organization of the gynoecium. Ovule number appears to determine ovary structure. Many-seeded capsules are retrieved as the ancestral state of Hydrophyllaceae. At least seven transitions to fruits with (one to) four seeds and four reversals (i.e., from four- to many-seeded fruits) were reconstructed in Hydrophyllaceae. Several shifts in seed number from "many" to "four" and back to "many" have taken place in capsular-fruited Hydrophyllaceae, a strikingly high number considering that seed number is virtually conserved across the rest of the order. The groups with a conserved seed number of four are characterized by indehiscent schizocarps or drupes and by seeds that are integrated into mericarps. This functional integration probably acts as an evolutionary constraint to shifts in seed number.

Low bee visitation rates explain pollinator shifts to vertebrates in tropical mountains

Evolutionary shifts from bee to vertebrate pollination are common in tropical mountains. Reduction in bee pollination efficiency under adverse montane weather conditions was proposed to drive these shifts. Although pollinator shifts are central to the evolution and diversification of angiosperms, we lack experimental evidence of the ecological processes underlying such shifts. Here, we combine phylogenetic and distributional data for 138 species of the Neotropical plant tribe Merianieae (Melastomataceae) with pollinator observations of 11 and field pollination experiments of six species to test whether the mountain environment may indeed drive such shifts. We demonstrate that shifts from bee to vertebrate pollination coincided with occurrence at high elevations. We show that vertebrates were highly efficient pollinators even under the harsh environmental conditions of tropical mountains, whereas bee pollination efficiency was lowered significantly through reductions in flower visitation rates. Furthermore, we show that pollinator shifts in Merianieae coincided with the final phases of the Andean uplift and were contingent on adaptive floral trait changes to alternative rewards and mechanisms facilitating pollen dispersal. Our results provide evidence that abiotic environmental conditions (i.e. mountain climate) may indeed reduce the efficiency of a plant clade's ancestral pollinator group and correlate with shifts to more efficient new pollinators.

Conserved, divergent and heterochronic gene expression during Brachypodium and Arabidopsis embryo development

Key messageDevelopmental and transcriptomic analysis of Brachypodium embryogenesis and comparison with Arabidopsis identifies conserved and divergent phases of embryogenesis and reveals widespread heterochrony of developmental gene expression.Embryogenesis, transforming the zygote into the mature embryo, represents a fundamental process for all flowering plants. Current knowledge of cell specification and differentiation during plant embryogenesis is largely based on studies of the dicot model plant Arabidopsis thaliana. However, the major crops are monocots and the transcriptional programs associated with the differentiation processes during embryogenesis in this clade were largely unknown. Here, we combined analysis of cell division patterns with development of a temporal transcriptomic resource during embryogenesis of the monocot model plant Brachypodium distachyon. We found that early divisions of the Brachypodium embryo were highly regular, while later stages were marked by less stereotypic patterns. Comparative transcriptomic analysis between Brachypodium and Arabidopsis revealed that early and late embryogenesis shared a common transcriptional program, whereas mid-embryogenesis was divergent between species. Analysis of orthology groups revealed widespread heterochronic expression of potential developmental regulators between the species. Interestingly, Brachypodium genes tend to be expressed at earlier stages than Arabidopsis counterparts, which suggests that embryo patterning may occur early during Brachypodium embryogenesis. Detailed investigation of auxin-related genes shows that the capacity to synthesize, transport and respond to auxin is established early in the embryo. However, while early PIN1 polarity could be confirmed, it is unclear if an active response is mounted. This study presents a resource for studying Brachypodium and grass embryogenesis and shows that divergent angiosperms share a conserved genetic program that is marked by heterochronic gene expression.

FLORISTIC STUDY ON ANGIOSPERMS SURROUNDING THE MEDAVAKKAM LAKE, CHENGALPATTU DISTRICT, TAMIL NADU, INDIA

Biodiversity plays a significant role in maintaining the ecosystem for their sustainable utilization. A preliminary survey was conducted to document the diversity and economic importance of the angiosperms around the Medavakkam Lake, Chengalpattu district, Tamil Nadu. The study area act as a seed bank for native species and provide suitable conditions to endemic and certain endangered species. Diversity indices of the study area was found significant, in which the species abundance, richness and evenness were found. A total of 71 species belonging to 36 families of angiosperms were documented. Among which the Dicotyledons plants were 87.32% and monocotyledon plants were 12.67% of total flora reported. The study area was dominated by the family fabaceae (14.1%) with ten species. Habit wise classification of plants reveal that trees are predominant with 32%, followed by hers (25%), Shrubs (21%), Climbers (13%), undershrubs (6%) and grasses (3%). The Simpson Diversity Index, Shannon Wiener Index and evenness index of the study area is 0.777, 1.5634 and 0.8725 respectively. These plants was found with enormous benefits to the mankind such as medicinal, edible, timber, ornamental, oil and other sources. This investigation divulges that the Medavakkam Lake has substantial angiosperm diversity served as major source for native plants having greater economic importance.

Plastid and nuclear phylogenomic incongruences and biogeographic implications of Magnolia s.l. (Magnoliaceae)

AbstractMagnoliaceae, an assemblage of early diverged angiosperms, comprises two subfamilies, speciose Magnolioideae with approximately 300 species in varying numbers of genera and monogeneric Liriodendroideae with two species in Liriodendron L. This family occupies a pivotal phylogenetic position with important insights into the diversification of early angiosperms, and shows intercontinentally disjunct distribution patterns between eastern Asia and the Americas. Widespread morphological homogeneity and slow substitution rates in Magnolia L. s.l. resulted in poorly supported phylogenetic relationships based on morphology or molecular evidence, which hampers our understanding of the genus’ temporal and spacial evolution. Here, based on the newly generated genome skimming data for 48 Magnolia s.l. species, we produced robust Magnolia phylogenies using genome‐wide markers from both plastid genomes and single nucleotide polymorphism data. Contrasting the plastid and nuclear phylogenies revealed extensive cytonuclear conflicts in both shallow and deep relationships. ABBA‐BABA and PhyloNet analyses suggested hybridization occurred within sect. Yulania, and sect. Magnolia, which is in concordance with the ploidy level of the species in these two sections. Divergence time estimates and biogeographic reconstruction indicated that the timing of the three tropical Magnolia disjunctions coincided with the mid‐Eocene cooling climate and/or late Eocene climate deterioration, and two temperate disjunctions occurred much later, possibly during the warm periods of the Miocene, hence supporting the boreotropical flora concept of Magnolia s.l.