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A key question in insect community ecology is whether parasitoid assemblages are structured by the food plants of their herbivore hosts. Tritrophic communities centred on oak‐feeding cynipid gallwasps are one of the best‐studied tritrophic insect communities. Previous work suggests that host plant identity is a much stronger predictor of oak–cynipid interactions than of cynipid–parasitoid interactions. However, these relationships have not been formally quantified. We reason that the potential for ‘bottom‐up’ effects should increase with host plant phylogenetic diversity. We, therefore, generated quantified interaction network data for previously unstudied tritrophic cynipid communities in Sichuan, China, where, in addition to Quercus, cynipid host plants include Castanea, Castanopsis and Lithocarpus. We characterise these communities taxonomically and compare the extent to which host plant taxonomy predicts plant–herbivore and plant–parasitoid associations. We sampled 42,620 cynipid galls of 176 morphotypes from 23 host plant species, yielding over 4500 specimens of 64 parasitoid morphospecies. Many parasitoids were identifiable to chalcidoid taxa present in other Holarctic oak cynipid communities, with the addition of Cynipencyrtus (Cynipencyrtidae). As elsewhere, Sichuan parasitoid assemblages were dominated by generalists. Gallwasp–plant interaction networks were significantly more modular than parasitoid–plant association networks. Gallwasps were significantly more specialised to host plants (i.e. had higher mean d' values) than parasitoids. Parasitoid assemblages nevertheless showed significant plant‐associated beta diversity, with a dominant turnover component. We summarise parallels between our study and other Fagaceae‐associated cynipid communities and discuss our findings in light of the processes thought to structure tritrophic interactions centred on endophytic insect herbivores. [ABSTRACT FROM AUTHOR]

Gnomoniopsis castaneae is internationally recognized as a destructive pathogen of chestnut species. Primarily associated with nut rot, it has also been associated with branch and stem cankers of chestnut and as an endophyte of multiple additional hardwood species. The present study evaluated implications of the recently reported United States presence of the pathogen for domestic Fagaceae species. Stem inoculation assays of Castanea dentata, C. mollissima, C. dentata x C. mollissima, and Quercus rubra (red oak) seedlings were utilized to examine the cankering ability of a regional isolate of the pathogen. The pathogen induced damaging cankers in all assessed species and significant stem girdling in all chestnut species. No previous study has associated the pathogen with damaging infection in Quercus species, and its presence in the United States has the potential to compound ongoing chestnut recovery programs and oak regeneration problems within forest systems. [ABSTRACT FROM AUTHOR]

Background and Aims Introgressive hybridization poses a challenge to taxonomic and phylogenetic understanding of taxa, particularly when there are high numbers of co-occurring, intercrossable species. The genus Quercus exemplifies this situation. Oaks are highly diverse in sympatry and cross freely, creating syngameons of interfertile species. Although a well-resolved, dated phylogeny is available for the American oak clade, evolutionary relationships within many of the more recently derived clades remain to be defined, particularly for the young and exceptionally diverse Mexican white oak clade. Here, we adopted an approach bridging micro- and macroevolutionary scales to resolve evolutionary relationships in a rapidly diversifying clade endemic to Mexico. Methods Ecological data and sequences of 155 low-copy nuclear genes were used to identify distinct lineages within the Quercus laeta complex. Concatenated and coalescent approaches were used to assess the phylogenetic placement of these lineages relative to the Mexican white oak clade. Phylogenetic network methods were applied to evaluate the timing and genomic significance of recent or historical introgression among lineages. Key Results The Q. laeta complex comprises six well-supported lineages, each restricted geographically and with mostly divergent climatic niches. Species trees corroborated that the different lineages are more closely related to other species of Mexican white oaks than to each other, suggesting that this complex is polyphyletic. Phylogenetic networks estimated events of ancient introgression that involved the ancestors of three present-day Q. laeta lineages. Conclusions The Q. laeta complex is a morphologically and ecologically related group of species rather than a clade. Currently, oak phylogenetics is at a turning point, at which it is necessary to integrate phylogenetics and ecology in broad regional samples to figure out species boundaries. Our study illuminates one of the more complicated of the Mexican white oak groups and lays groundwork for further taxonomic study. [ABSTRACT FROM AUTHOR]

Quercus infectoria Oliv. is a taxon with high morphological variation, and many infra‐specific have been described in this species, of which Q. infectoria Oliv. subsp. veneris (A.Kern) Meikle is present in the flora of Iran. In a taxonomic review of the Quercus L. taxa in Iran, based on morphological and micromorphological evidence, we recognized a new combination: Q. infectoria Oliv. subsp. boissieri (Reut.) O. Schwarz var. pfaeffingeri (Kotschy) Jamzad and Panahi, as a distinct taxon. Since the valid subspecific name for this taxon is subsp. veneris (A.Kern) Meikle var. pfaeffingeri, and the basionym of this name was not defined in the published manuscript. Here we correct the authorship and validate this name. Furthermore, we present the taxonomic history of Q. infectoria, descriptions of infraspecific taxa, a distribution map in Iran, ecological notes, and an identification key to infraspecific taxa. [ABSTRACT FROM AUTHOR]

The full-grown larval stage of Curculio mexicanus Gibson is described and illustrated for the first time. The larvae were collected in fruits (acorns) of several species of Quercus L. (Fagaceae): Q. pinnativenulosa C. H. Mull, Q. xalapensis Bonpl., Q. germana Schltdl. & Cham., Q. candicans Née and Q. polymorpha Schltdl. & Cham; all species with wide distribution in the Sierra Madre Oriental and representative of the mountain mesophilic forest of Xalapa, Veracruz, Mexico. The record of Curculio mexicanus in Veracruz constitutes the first report for this species, as previously it was only known in Chiapas, Durango, Guerrero, Nayarit, Oaxaca and Sonora, in Quercus magnoliifolia Née (Q. macrophylla Née). Of those five mentioned host species of Quercus: Q. xalapensis and Q. germana are listed as vulnerable; thus, it is important to carry out research concerning this interaction in order to develop conservation strategies for these oaks as well as correct management and control of the weevils. [ABSTRACT FROM AUTHOR]

Lithocarpus dahuensis, a new Fagaceae species from Fujian Province, China, is described and illustrated. The new species is morphologically similar to L. konishii, but its oblanceolate leaf blade has more pairs of acute teeth on the margin, denser lateral veins, smaller cupules enclosing up to 1/4-1/3 of the nut, and its nut is only half as long as those of L. konishii. The plastome of L. dahuensis was 161,303 bp in length and displayed the typical quadripartite structure. Phylogenetic analyses distinguished L. dahuensis from L. konishii with strong support based on whole plastome and nrITS, respectively. [ABSTRACT FROM AUTHOR]

ABSTRACT Although the frequency of ancient hybridization across the Tree of Life is greater than previously thought, little work has been devoted to uncovering the extent, timeline, and geographic and ecological context of ancient hybridization. Using an expansive new dataset of nuclear and chloroplast DNA sequences, we conducted a multifaceted phylogenomic investigation to identify ancient reticulation in the early evolution of oaks (Quercus). We document extensive nuclear gene tree and cytonuclear discordance among major lineages of Quercus and relatives in Quercoideae. Our analyses recovered clear signatures of gene flow against a backdrop of rampant incomplete lineage sorting, with gene flow most prevalent among major lineages of Quercus and relatives in Quercoideae during their initial radiation, dated to the Early‐Middle Eocene. Ancestral reconstructions including fossils suggest ancestors of Castanea + Castanopsis, Lithocarpus, and the Old World oak clade probably co‐occurred in North America and Eurasia, while the ancestors of Chrysolepis, Notholithocarpus, and the New World oak clade co‐occurred in North America, offering ample opportunity for hybridization in each region. Our study shows that hybridization—perhaps in the form of ancient syngameons like those seen today—has been a common and important process throughout the evolutionary history of oaks and their relatives. Concomitantly, this study provides a methodological framework for detecting ancient hybridization in other groups. [ABSTRACT FROM AUTHOR]

Quercus subsect. Campylolepides contains three species: Q. acutissima, Q. variabilis and Q. chenii, which is the East Asian clade of Quercus section Cerris. Species formation and phylogeography of whole subsection or species within the subsection have been studied in detail. It has been also found that section Cerris had an ancient gene introgression with section Ilex, which led to the plastid capture. However, the specific evolutionary history of plastids in subsect. Campylolepides and section Ilex remains unclear. Our study performed low-coverage whole genome sequencing on 15 samples from section Ilex and integrated previously published data from subsect. Campylolepides and its relatives, resulting in a total of 325 resequencing data, of which 276 individuals were from three subsect. Campylolepides species and 19 populations. We assembled 325 plastids to perform phylogeographic analysis. The results were as follows: (1) There were shared haplotypes among three species of subsect. Campylolepides, but the plastid haplotypes of the entire subsect. Campylolepides form a monophyletic branch nested within section Ilex species which are distributed from central China to Liangshan, Sichuan. (2) A relictual haplotype of subsect. Campylolepides from the Liaodong Peninsula clustered with Q. pseudosetulosa, a specie of the section Ilex. (3) Both plastid capture events occurred in the middle Miocene, after which no plastid capture occurred between subsect. Campylolepides and section Ilex. It is hypothesized that subsect. Campylolepides and section Ilex have formed almost complete reproductive isolation. The study demonstrates that section Ilex and subsect. Campylolepides have undergone ancient plastid capture events in their evolution history, ultimately lead to the gradual formation of relatively independent evolutionary paths. [ABSTRACT FROM AUTHOR]

Northern Hemisphere forests changed drastically in the early Eocene, 50 million years ago, with the diversification of the oaks and their relatives. Cooling climates over the next 20 million years fostered the spread of temperate biomes that became increasingly dominated by the Fagaceae. Here I provide a chronicle to the results of a collaborative project (Zhou et al. 2022) that resolved major evolutionary events, including support for the origin of the oaks and evidence for ancient genome-wide signatures of hybridization across the family using analyses of nuclear and chloroplast genomes. Ecological correlations related to animal dispersal and mutualism with fungi are implicated in triggering waves of continental radiations beginning with the origin of major lineages just after the K-Pg (aka K-T) mass extinction event, 66 million years ago. Movement of genes between species was detected at multiple time scales suggesting that hybridization has long been part of the genetic legacy of Fagaceae. As the major oak lineages moved into their current ranges in the early Miocene, hybridization likely occurred between ancestral species of sections: Ilex and Cerris, Virentes and Quercus, Protobalanus and Quercus, and Ponticae and Quercus. Some of these historical hybridization events may have resulted in an adaptive advantage for the species involved. [ABSTRACT FROM AUTHOR]

Research was undertaken in southeastern Taiwan covering a study area of 80 km² and an altitudinal range between 50 and 1,630 m.a.s.l. One hundred and twenty-four quadrat plots of 20 m² were set up to investigate the forest composition within the area. In total, we recorded 26 Fagaceae species, showing that this area has the highest Fagaceae diversity in Taiwan. Of these 26 species, 11 are endemic to Taiwan and 10 frequently possess prominent buttresses. Our results show that the Fagaceae diversity of the forests in our study area is unique in Taiwan. We conclude that it is necessary to create a conservation area in order to protect these forests and appeal for the support of Fagaceae lovers worldwide. [ABSTRACT FROM AUTHOR]

Quercus is the largest genus of the family Fagaceae in the world and the second-largest in Vietnam, with approximately 50 species. However, the phylogeny study of the Quercus genus in Vietnam has yet to be thoroughly explored. In this study, we utilize the genome-wide singlenucleotide polymorphisms (SNPs) data obtained through Multiplexed Inter Simple Sequence Repeat Genotyping by sequencing (MIG-seq) to explore the phylogenetic relationships among Quercus species in Vietnam. The results of this study reveal that all Quercus species in Vietnam belong to subgenus Cerris and the phylogenetic analysis strongly supports the recognition of two infrageneric sections: Quercus and Ilex section for the Vietnamese Quercus. These results also confirm that the monophyly of Quercus in Vietnam is strongly supported by both morphological and molecular data. The results of this study also align entirely with previous research, indicating that Quercus species in Asia fall under the subgenus Cerris, comprising two sections: section Ilex and section Cyclobalanopsis. [ABSTRACT FROM AUTHOR]

Background: The great species diversity of Lithocarpus is associated with interspecific fruit morphological variation, represented by acorn (AC) and enclosed receptacle (ER) fruit types. Species representing both fruit types co-occur in the same forests and share two distribution centers in southern China and southeastern Asia. The predation selection hypothesis suggests that the fruit morphological mechanical trade-off between two fruit types could represent divergent dispersal strategies under varied predation pressures. By integrating phylogenetic construction with fruit morphometric study, we tried to verify the predation selection hypothesis and elucidate the fruit type evolution of Lithocarpus, which is critical in interpreting the distribution and diversification of the genus. Results: We identified the functional trade-off between the two fruit types: ER species have bigger seeds which are enclosed mainly by receptacle representing stronger physical defense; whereas the seeds of AC species are smaller and enclosed mainly by thin pericarp representing lower mechanical protection. Despite some reversals from ER back to AC, the ancestral state reconstruction in combination with thermal analysis supports the hypothesis that ER is the derived fruit type from AC-like ancestors independently across all clades. Conclusion: Our results support the predation selection hypothesis by verifying the mechanical trade-off between the two fruit types. We propose a divergent selection theory for the two fruit types: the seed size and mechanical defense of AC species become smaller, whereas those of ER species become larger and require more morphological modifications in the receptacle. This signified the importance of the receptacle in differentiating the two fruit types and in the fruit morphological modification through evolutionary time. We found that the ER-type species evolved independently in all clades and across varied climates from tropical to warm temperate regions. As ER fruits are products of convergent evolution, we propose to examine the predation and dispersal variation between two fruit types in the future to verify whether predation selection is the reason behind fruit type evolution of the stone oaks. [ABSTRACT FROM AUTHOR]

Simple Summary: The external climate is an important factor affecting plant phenology. In this study, we monitored seed rain of four sympatrically distributed Fagaceae species in the Qinling Mountains of China for 10 consecutive years and also collected local climate data to clarify how the seed rain dynamics of four sympatric species changed, whether and how climate variability will affect seed rain drop dynamics of the four sympatric species, and how can the four species better coexist in the same domain. We found there were differences in the seed rain dynamics among the four species, which indicated that there was no concentrated flowering and fruiting among different species. Thus, they could well avoid fierce competition for similar resources, which was also an important reason why different species could co-exist well in the same domain. In addition, our study also found that the seed rain dynamics of these four plants were different in response to different climatic factors, which may be also conducive to their better sympatric distribution. Seed rain, as the beginning of species dispersal, is a key process for forest structure and regeneration. In this study, the seed rain of four Fagaceae sympatric plant species (Castaneamollissima, Quercus aliena, Quercus variabilis, and Quercus serrata) in the Qinling Mountains were monitored for ten consecutive years, and the responses of seed rain dynamics of the four species to major climatic factors (temperature and precipitation) were analyzed. We found there were significant differences in the seed rain dynamics between C. mollissima of Castanea and the other three species of Quercus in the initial period and end period and the duration of the whole seed rain process among the 10 years. This could indicate to some extent that there was no concentrated flowering and fruiting among different plants of different genera, and they could well avoid fierce competition for similar resources and coexist in the same region. This may also be a reproductive strategy for plants. Seed rain dynamics of different plant species had different sensitivities to climate factors (temperature and precipitation), which indicated that mainly because of their different responses to climate factors, they could well avoid fierce competition for similar climate resources. In addition, the differences in seed rain dropping dynamics could reduce consumption in large numbers by seed predators, thereby promoting their own dispersal and regeneration. All of the above contribute to their better coexistence in the same domain. [ABSTRACT FROM AUTHOR]

Quercus mangdenensis Binh & Ngoc, sp. nov. (Fagaceae) is newly described from Mang Den Town in the central highland of Vietnam. The new species is characterized by lanceolate to oblong-lanceolate leaves with entire margin, 1–5-fruited infructescence, larger fruit size 6–10.5 cm long, broadly bowl-shaped cupules enclosing 1/5 of the nut, bracts of cupule entire and arranged in 5–7 rings, and cylindrical-ellipsoid and basally flat nuts 4.5–7.5 cm long. Quercus mangdenensis is morphologically similar to Q. bidoupensis Binh & Ngoc and Q. kontumensis A.Camus in having similar leaf shape, cuneate leaf base, and bracts arrangement in cupules. However, it differs from Q. bidoupensis and Q. kontumensis by cupules broadly bowl-shaped, much larger fruits, cylindrical-ellipsoid nut shape, and cupule enclosing 1/5 of the nuts. A description, photographs, and preliminary species conservation status of the new species are also provided. [ABSTRACT FROM AUTHOR]

The dominant species of a biome can be regarded as its genuine indicator. Evergreen broadleaved forests (EBLFs) in subtropical East Asia harbor high levels of species biodiversity and endemism and are vital to regional carbon storage and cycling. However, the historical assembly of this unique biome is still controversial. Fagaceae is the most essential family in East Asian subtropical EBLFs and its dominant species are vital for the existence of this biome. Here, we used the dominant Fagaceae species to shed light on the dynamic process of East Asian subtropical EBLFs over time. Our results indicate high precipitation in summer and low temperature in winter are the most influential climatic factors for the distribution of East Asian subtropical EBLFs. Modern East Asian subtropical EBLFs did not begin to appear until 23 Ma, subsequently experienced a long‐lasting development in the Miocene and markedly deteriorated at about 4 Ma, driven jointly by orogenesis and paleoclimate. We also document that there is a lag time between when one clade invaded the region and when its members become dominant species within the region. This study may improve our ability to predict and mitigate the threats to biodiversity of East Asian subtropical EBLFs and points to a new path for future studies involving multidisciplinary methods to explore the assembly of regional biomes. [ABSTRACT FROM AUTHOR]

Epigenetic regulators are proteins involved in controlling gene expression. Information about the epigenetic regulators within the Fagaceae, a relevant family of trees and shrubs of the northern hemisphere ecosystems, is scarce. With the intent to characterize these proteins in Fagaceae, we searched for orthologs of DNA methyltransferases (DNMTs) and demethylases (DDMEs) and Histone modifiers involved in acetylation (HATs), deacetylation (HDACs), methylation (HMTs), and demethylation (HDMTs) in Fagus, Quercus, and Castanea genera. Blast searches were performed in the available genomes, and freely available RNA‐seq data were used to de novo assemble transcriptomes. We identified homologs of seven DNMTs, three DDMEs, six HATs, 11 HDACs, 32 HMTs, and 21 HDMTs proteins. Protein analysis showed that most of them have the putative characteristic domains found in these protein families, which suggests their conserved function. Additionally, to elucidate the evolutionary history of these genes within Fagaceae, paralogs were identified, and phylogenetic analyses were performed with DNA and histone modifiers. We detected duplication events in all species analyzed with higher frequency in Quercus and Castanea and discuss the evidence of transposable elements adjacent to paralogs and their involvement in gene duplication. The knowledge gathered from this work is a steppingstone to upcoming studies concerning epigenetic regulation in this economically important family of Fagaceae. [ABSTRACT FROM AUTHOR]

The aim of this study is to present a characteristic of monodominant communities of Hungarian Oak in Maleshevska Mountain. Investigations have been carried out in 2018 - 2020 (March - September) to evaluate some structural indicators: species composition, abundance, forest inventory. Biological type, life forms and floristic elements for the vascular plants have been determined. Results of the floristic analysis of the investigated phytocoenosis have shown 63 species of vascular plants, referred to 22 families and 52 genera. Hungarian Oak communities belong to habitat 91M0 Pannonian-Balkanic turkey oak-sessile oak forests. The results have been compared with other studies of the Hungarian Oak communities in Bulgaria. [ABSTRACT FROM AUTHOR]

A new species of stone oak, Lithocarpus tapanuliensis Harapan, W.H.Tan, Nurainas & Strijk from South Tapanuli, North Sumatra, Indonesia is described. We provide colour photographs, a distribution map and a new IUCN conservation status assessment for inclusion on the global Red List. The unique cupule morphology, particularly the shape, placement and distinctness of the cupule protuberances, are distinctive from other Lithocarpus species in the region. Ecological interactions (e.g. consumption and nesting) with Tapanuli orangutans were recorded in the field. [ABSTRACT FROM AUTHOR]

Inferring the geographic mode of speciation is essential for explaining the generation and assembly of biodiversity, but has been rarely applied to the temperate flora of China. Fagus longipetiolata and F. lucida are a sister pair of beech species with largely overlapping ranges in subtropical China, however, little is known about the geographic mode of speciation and the formation of their sympatric distributions. In this study, we used IMa2 and fastsimcoal2 to simulate the speciation history of the two sisters. On the basis of 11 nuclear loci screened for 27 populations/species, their divergence time was estimated to 8.37 Mya by IMa2, and weak interspecific gene flow was detected. The simulation by fastsimcoal2 found that F. longipetiolata and F. lucida diverged ~8.53 Mya, then came into contact and hybridized at 0.8 Mya. The extended Bayesian skyline plots indicated that F. lucida began demographic expansion prior to the Pleistocene at 3 Mya, whereas F. longipetiolata increased its effective population size during the Quaternary, between 0.8 and 0.5 Mya. Ecological niche analysis and niche modelling showed that the two beeches had subtle niche differentiation and their projected distributions were largely overlapped across the late Quaternary. These results, coupled with well-studied fossil records in Fagus , demonstrate that these two beech species diverged allopatrically at the high latitudes of the Northern Hemisphere, and came into contact and hybridized with each other after successive migrations into subtropical (i.e. warm temperate) China recently. However, the two beeches may have developed strong intrinsic reproductive barriers due to long-term allopatry, allowing them to coexist in subtropical China. Our results illuminate the assembly history of the temperate woody flora in subtropical China, supporting that many relict temperate lineages in subtropical China may have established their populations recently. [ABSTRACT FROM AUTHOR]

Lithocarpus cadamensis Ngoc & Son, a new species of Fagaceae, is described and illustrated from Mt. Ca Dam, Tra Bong District, Quang Ngai Province, central Vietnam. The new species is characterized by its large leaf blades with long petioles, solitary and subsessile cupules which almost completely cover the nut, and spiny cupule scales, in a combination that clearly differs from the previously known species of Lithocarpus including the most similar species in the region, L. campylolepis, L. eucalyptifolius, and L. gougerotae. A MIG-seq phylogeny based on genome-wide SNPs reveals a phylogenetic position close to L. eucalyptifolius, from which the new species is differentiated by multiple morphological characters. A morphological description and comparison with related species, photographs, line drawing, preliminary conservation status, and DNA barcode sequences are provided for the new species. [ABSTRACT FROM AUTHOR]

A new species, Quercus sontraensis Ngoc, Binh & Son is described from Son Tra Nature Reserve, Son Tra Peninsula, Central Vietnam. We examined the morphology and constructed a highly resolved phylogeny of Q. sontraensis and its relatives (including Q. langbianensis and Q. cambodiensis) using Multiplex ISSR genotyping by sequencing (MIG-seq). The morphological analyses and molecular evidence support the distinction between the new species (Q. sontraensis) and its relatives. [ABSTRACT FROM AUTHOR]

• A spatiotemporal model was developed to understand the Fagaceae acorn persistence. • Fagaceae acorns use three mechanisms to cope with post-dispersal conditions. • Climate change will significantly affect the persistence and germination ecology of Fagaceae acorns. Fagaceae is an iconic plant family with 1000+ species distributed predominantly in the northern hemisphere. The reproductive ecology of the Fagaceae species is highly complex, and in the past three centuries, understanding the fruit masting strategies, dispersal, pathogen pressure, and storage has enjoyed steady research interest. However, the interrelationship between these factors is surprisingly less explored, undermining how acorns survive the post-dispersal period. The ability of fruits (acorns, nuts) to survive post-dispersal conditions starts during the maturation drying stage. Successful fruit production depends on the maternal environment, with a 'good fruit production year' occurring every few years. This phenomenon might out-maneuver predators by providing sufficient numbers to be consumed but still leaving enough for germination. Because most Fagaceae species have desiccation-sensitive (DS) fruits, survival after dispersal is challenging due to frequent dry spells. Fruit size is not phylogenetically conserved within the genus, with the average fruit mass of Castanea being 50 times higher than the desiccation-tolerant genus Fagus. Larger fruit size may be an adaptation in dry areas because prolonged drying continuously desiccates large-sized cotyledons before desiccating embryos. For species adapted to dry environments, synchronizing dispersal with the growing season could be beneficial, but exceptions exist. Many consumers, such as rodents, aid in the dispersal of fruits, but some fruits are killed in the process, especially those predated late. Upon settling on a site, the pericarp protects the embryo to a certain extent; if drying occurs, the cotyledons become the first site of water loss. However, under extreme drying, survival depends on sporadic rainfall, i.e., wet-dry cycle, which aids in maintaining the critical moisture content required by the fruits for survival. Nonetheless, these adaptive mechanisms are challenged by climate change, which affects the maturation, persistence, and seedling establishment of numerous Fagaceae species. [ABSTRACT FROM AUTHOR]

Quercus (oaks) is a large and important genus of woody angiosperms occurring in a wide range of environments and often occupying a dominant position in temperate forests of the Northern Hemisphere or being a minor component in some subtropical and tropical forests. A reliable determination of fossil dispersed oak pollen requires combined light, scanning electron (SEM) and transmission electron microscopy (TEM) studies and relevant comparative data on extant oak species. We provide SEM and TEM data on 22 extant Quercus spp. representing all sections of the genus. The main objectives of our study were to clarify the nature of the so-called geniculus, a characteristic equatorial bulge in the exine of the colpus found in many oak species, and to test previous hypotheses about the structural basic units of the exine in Quercus. Our ontogenetic study and oxidative experiment involving several Quercus spp. and one Trigonobalanus sp. resulted in a more accurate interpretation of the nature of the geniculus and exine elements, their different developmental states and, therefore, their more reliable application in the systematics and evolution of the genus Quercus and Fagaceae in general. [ABSTRACT FROM AUTHOR]

Fagaceae species are increasingly used as models to elucidate the process and mechanism of adaptation and speciation by integrating ecology, evolution and genomics. The genus Castanopsis belongs to the family Fagaceae and is mainly distributed across subtropical and tropical Asia. In the present study, we reported the first chromosome‐scale genome assembly of Castanopsis tibetana, a common species of evergreen broadleaved forests in subtropical China. The combination of Nanopore sequencing and Hi‐C technologies enabled a high‐quality genome assembly. The final assembled genome size of C. tibetana was 878.6 Mb (97.6% of the estimated genome size), consisting of 477 contigs with an N50 length of 3.3 Mb. The benchmarking universal single‐copy orthologue (BUSCO) assessment indicated a completeness of 93.0%. Hi‐C scaffolding generated 12 pseudochromosomes, representing 98.7% of the assembled genome. Subsequently, 40,937 protein‐coding genes were predicted and 90.04% of them were functionally annotated. More than 476.9 Mb of repetitive sequences (54.3% of the genome) were identified, and the percentage of the genome covered by TE elements was 39.98%. Comparative genomics analysis revealed that C. tibetana was most closely related to Castanea mollissima and diverged at 18.48 Ma, and that C. tibetana has undergone considerable gene family expansion and contraction. Evidence of positive selection was detected in 53 genes, which showed different arrangement pattern compared to Quercus robur. The chromosome‐scale genome assembly of C. tibetana will expand Fagaceae genome resources across the family and provide a powerful comparative framework to study the adaptation and evolution of Fagaceae trees. [ABSTRACT FROM AUTHOR]

Two new Rhyncaphytoptus species (Diptilomiopidae: Rhyncaphytoptinae) including R. fagientalissp. nov. and R. quercivagranssp. nov. were collected from Fagus orientalis Lipsky. (Fagaceae) and Quercus castaneifolia C. A. Mey., 1831 (Fagaceae), respectively in Sari county, Mazandaran province, North of Iran. They are described and illustrated. [ABSTRACT FROM AUTHOR]

In the family Fagaceae, fertilization is delayed by several weeks to 1 year after pollination, leading to 1‐ or 2‐year fruiting species depending on whether fruiting occurs in the same or the next year after flowering. To investigate physiological responses underlying the regulation of delayed fertilization, we monitored seasonal changes in genome‐wide gene expression in tissues including leaves and buds over 2 years under natural conditions in one‐ (Quercus glauca) and 2‐year fruiting species (Lithocarpus edulis). Genes associated with metabolic changes in response to winter cold, photosynthesis and cell proliferation, which are essential for survival and growth, showed highly conserved seasonal expression profiles between species. However, seasonal expression profiles diverged between species in genes associated with pollination, an important process contributing to the origin and maintenance of the reproductive barrier between plant species. By comparing seasonal progression of ovule development and gene expression in pistillate flowers, we revealed that ovules started developing after winter in the 2‐year fruiting species, which could be linked to the activation of genes involved in fertilization and female gametophyte development after winter. These findings suggest that the 2‐year fruiting species may have evolved a requirement of winter cold to prevent fertilization before winter and facilitate fertilization and embryo development in the following spring when temperature rises. This study offers new possibilities to explore the evolution of reproductive strategies in Fagaceae. [ABSTRACT FROM AUTHOR]

• Forty-seven Quercus species (oaks) were recorded in South Africa. • Several taxa are naturalising and invading in South Africa. • Naturalisation is limited to the urban-wildland interface and riparian corridors. • Riverbank steepness can mediate oak naturalisation in a riparian corridor. • iNaturalist is a useful tool for studying the invasion ecology of alien species. Hundreds of species of alien trees have been introduced and widely cultivated in South Africa, and many species have become invasive. Despite their long residence time and widespread cultivation, little is known about the introduction history, current status, and invasion ecology of oaks (genus Quercus) in South Africa. This study reviews various aspects of the genus Quercus in South Africa. We determine the number of oak species present, assess their introduction status, map their distribution, highlight areas of putative naturalisation, and evaluate the usefulness of the community science platform iNaturalist for assessing these factors. We also conducted a field study to elucidate environmental factors that can mediate invasibility in a riparian zone. A literature search was conducted to review events associated with the introduction, cultivation and naturalisation of oaks and associated pests and diseases in South Africa. Records of Quercus species in South Africa were collated from herbaria, arboreta, the Southern African Plant Invader Atlas, the Plants of Southern Africa database and iNaturalist. A field study was conducted along the Eerste River in Stellenbosch to elucidate the role of environmental factors in mediating naturalisation. We found records of 47 Quercus taxa in South Africa which were refined to a list of 22 to 34 species likely present. The earliest record was for Quercus robur in 1656 but first records for most species date from between the late 1800s to the early 1900s. More than 99 % of presence and naturalisation records were of the ten commonly cultivated species. Quercus palustris, Q. robur , and Q. suber were categorised as invasive, and putative naturalisation was documented for Q. acutissima, Q. canariensis, Q. cerris, Q. ilex , and Q. nigra. Most naturalisation occurred at the urban-wildland interface and in riparian vegetation in Cape Town and Stellenbosch. Steepness of the riverbank was found to affect seedling recruitment in riparian areas. iNaturalist records shed new light on the presence, distribution, and introduction status of Quercus species in South Africa. However, taxonomic complexity and data quality complicated attempts to develop a robust inventory of Quercus in South Africa. Molecular studies are needed to achieve better resolution. Nonetheless, this study has greatly improved our understanding of the distribution and status of oaks in South Africa, with implications for their management. [ABSTRACT FROM AUTHOR]

Allocation strategies of carbon (C), nitrogen (N), and phosphorus (P) are key to the reproductive processes of plants. Nutrient allocation to seeds depends on defensive traits of seeds and fruit because greater nutritional contents attract more seed predators. To compare resource allocation strategies for reproductive and defensive traits across species, we calculated the cost of resource investment in reproductive organs for nine species from four genera and defensive traits for seven species from two genera of Fagaceae. The results showed that no single element is the common resource currency across species, but that the reproductive strategy of each species is regulated by C, N, or P. Reproduction in Fagus crenata was limited by N but not by C, whereas in Quercus serrata it was co‐limited by C and N. Among the seven Fagaceae species, there was a negative correlation between the thickness of the pericarp and the concentration of the total phenolics in the seed and pericarp, suggesting alternative strategies for developing defensive traits in ripening seeds with limited C‐based resources. Overall, our results highlighted the diversity of resource allocation strategies to reproduction and defensive traits of Fagaceae species. To better understand the masting phenomenon at the population or community levels, comprehensive consideration of the diversity of resource allocation strategies among species is worth exploring in the future. [ABSTRACT FROM AUTHOR]

The very little-known Quercus ×numidica Trabut, recently typified and synonymised to Q. ×kabylica Trabut, was found within the Cynosuro peltierii-Quercetum afaredis Laribi ex El Mokni ass. nov. (Quercion suberis Loisel 1971). Both the taxon and the syntaxon are described here for the first time for the oak forests of Kroumiria in Tunisia. The distribution, ecology and field photographs of the new taxon are presented and IUCN Red List assessment is provided in this paper. Threats at the national level are assessed and conservation measures for the taxon are proposed. [ABSTRACT FROM AUTHOR]

Fagaceae includes typical masting species that exhibit highly synchronized and fluctuating acorn production. Fagaceae shows an interesting feature in that fertilization is delayed by several weeks to more than 1 year after pollination. Although delayed fertilization was recorded over a century ago, the evolutionary advantage of delayed fertilization is still poorly understood. Here, we present a new hypothesis that delayed fertilization facilitates temporal niche differentiation via non-overlapping flowering times among species. Comparing flowering and fruiting times in 228 species from five genera in Fagaceae, we first show that there is a close association between a wider spread of flowering times and the likelihood of a 2-year fruiting habit in which there is a long delay from pollination to fertilization. To study the coevolution of flowering time and delayed fertilization, we developed a mathematical model that incorporates the effects of competition for pollinators, seed predator satiation and unfavourable season for reproduction on fitness. The model shows that delayed fertilization facilitates the diversification of flowering time in a population, which is advantageous for animal-pollinated trees that compete over pollinators. Our new hypothesis about the coevolution of delayed fertilization and flowering time will provide new insight into the evolution of masting. This article is part of the theme issue 'The ecology and evolution of synchronized seed production in plants'. [ABSTRACT FROM AUTHOR]

The understanding of ecological mechanisms shaping canopy arthropods community assembly, remains as one of the main targets of ecology. It is necessary to elucidate how abiotic factors such as precipitation shape arthropod communities in oak canopy. We evaluated the changes of canopy arthropod diversity assemblages associated to Quercus castanea along a precipitation gradient in four study sites, where Q. castanea occurs. Five mature Q. castanea trees were selected per site to collect canopy arthropods using fogging techniques. We collected 7,447 arthropods representing 754 morphospecies grouped into 16 different orders associated to Q. castanea along the precipitation gradient. We found differences in arthropod richness and abundance as well as in guild composition along the precipitation gradient. The general pattern showed higher canopy arthropod diversity in dry sites compared to wet sites. Also, arthropod guild composition differed along the precipitation gradient; dry sites harbored higher abundance of phytophages and detritivores, while wet sites had higher richness of phytophages and predators. Local climatic variables such as temperature were related to the canopy of Q. castanea arthropod community in dry sites. Our findings confirm that at a local scale, water availability is an important abiotic factor that generates changes in the assemblies of canopy arthropod community of Q. castanea, harboring more arthropod diversity in dry sites. We highlight the importance of conserving oak species because Mexico is the main center of richness, diversification and endemism of oaks in the northern hemisphere, and they represent key species in temperate forest harboring a great diversity of unique canopy arthropods. [ABSTRACT FROM AUTHOR]

Chalcone Isomerase (CHI) catalyzes the biosynthesis of flavonoids and secondary metabolism in plants. Currently, there is no systematic analysis of CHIs gene family in Fagaceae which is available. In this study, twenty-two CHI proteins were identified in five species of the Fagaceae family. The CHI superfamily in Fagaceae can be classified into three subfamilies and five groups using phylogenetic analysis, analysis of physicochemical properties, and structural prediction. Results indicated that serine (Ser) and isoleucine (Ile) residues determine the substrate preferred by active Type I Fagaceae CHI, and the chalcone isomerase-like (CHIL) of Fagaceae had active site residues. Adaptive analysis of CHIs showed that CHIs are subject to selection pressure. The active CHI gene of Fagaceae was located in the cytoplasm, and it had the typical gene structure of CHI and contains four exons. All the twenty-two identified CHIs had the conserved domain motif 3, and the different groups had their own structural characteristics. In the process of fatty acid binding protein (FAP) evolution to CHIL and CHI, the physical and chemical properties of proteins also had significant differences in addition to changes in protein functions. [ABSTRACT FROM AUTHOR]

Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) genotypes on the same plant samples of Chrysolepis chrysophylla (Douglas ex Hook.) Hjelmq. (Fagaceae; golden chinquapin) from 22 sites were used to determine genetic diversity and population structure. One site of C. sempervirens (Kellogg) Hjelmq. allowed interspecific vs. intraspecific comparisons. SSRs and SNPs yielded many similar results. Among-site variation contributed 13% to 17% of the genetic variation and Fst estimates of 0.14 to 0.17 were in the range expected among Fagaceae species rather than among populations within a species. The northern sites tended to group separately on the first two axes of multivariate scatterplots from southern sites. Sites in two geographically isolated areas were divergent: (i) the Hood Canal, Washington population was relatively more genetically distant from other golden chinquapin sites than was our C. sempervirens site; (ii) three coastal southern California sites were moderately diverged. The Hood Canal site had a negative inbreeding coefficient, fewer alleles, lower heterozygosity, and differed from the Skamania County, Washington site as well as all other sites. Hood Canal trees are distinguished by disjunct geography and by these molecular results. This suggests that the golden chinquapin near Hood Canal be treated as a management unit, and potential conservation actions are discussed. [ABSTRACT FROM AUTHOR]

Chloroplast genome diversity in cork oak (Quercus suber) is characterised by the occurrence of haplotypes that are akin to those found in other Mediterranean oak species, particularly in Q. ilex and Q. rotundifolia, suggesting the possible presence of an introgressed chloroplast lineage. To further investigate this pattern, we reconstructed chloroplast haplotypes by sequencing four chloroplast markers (cpDNA), sampled across 181 individuals and 10 taxa. Our analyses resulted in the identification of two diversified chloroplast haplogroups in Q. suber, corresponding to a geographically widespread lineage and an Afro-Iberian lineage. Time-calibrated phylogenetic analyses of cpDNA point to a Miocene origin of the two haplogroups in Q. suber, suggesting that the Afro-Iberian lineage was present in cork oak before the onset of glaciation periods. The persistence of the two haplogroups in the western part of the species distribution range may be a consequence of either ancient introgression events or chloroplast lineage sorting, combined with different fixation in refugia through glaciation periods. Our results provide a comprehensive insight on the origins of chloroplast diversity in these ecologically and economically important Mediterranean oaks. [ABSTRACT FROM AUTHOR]

In many but not all recalcitrant Quercus seeds, water loss during drying only occurs through the scar. Consequently, the embryo axis sitting on the opposite side of the scar is well protected from desiccation. However, whether such a mechanism is common throughout Fagaceae species is unexplored. Similarly, little is known about the desiccation response of other Fagaceae genera. Germination and desiccation tolerance of Castanopsis sclerophylla (Lindl. & Paxton) Schottky (Fagaceae) were studied by drying the seeds with silica gel. Fresh seeds had a moisture content (MC) of 36% and germinated to 92.5% when incubated at 15/20 °C. Drying seeds to 22.5% and 20.7% MC decreased germination to 27% and 5%, respectively, indicating that seeds are recalcitrant. X-ray computed tomography and photomicrographs showed that the embryo axis of C. sclerophylla is located just below the scar. Regardless of drying occurring either through only the scar or the whole pericarp, embryo drying was deemed unavoidable. Nevertheless, germination percentage during drying showed exceptional similarities with the other Fagaceae species. [ABSTRACT FROM AUTHOR]

In the present article, the establishment of the species Castanopsis: C. bulgarica Mantzouka, Ivanov, and Bozukov is proposed after the study of a new fagaceous fossil wood stem discovered in 2016 from a new Late Miocene to Early Pliocene plant fossiliferous locality east of Boboshevo town, south‐west Bulgaria. A detailed palaeoxylotomical study of the fossil wood revealed characteristics of the 'evergreen Quercus type' (e.g. the gradual porosity of the vessels, the existence of two types of rays: uniseriate and multiseriate aggregate, the oval shape of the solitary vessels outline, the occurrence of tracheids) as well as heterocellular compound‐aggregate rays, typical for Castanopsis. Similarities and differences of the anatomical characteristics/features of the studied specimen with the descriptions of the fossil representatives of Fagaceae (Quercoxylon, Lithocarpoxylon, and Castanopsis) along with its botanical affinities are discussed. A taxonomic list of the Bulgarian fossil fagaceous record of the same age and their nearest living relatives is provided. Emended xylotomical keys with the addition of Castanopsis have been created. Moreover, the presence of evergreen Castanopsis species with heterocellular rays of two distinct sizes in the fossil record of the 'evergreen oak woods' is supported. [ABSTRACT FROM AUTHOR]

Eocene Baltic amber forms the largest amber deposit worldwide; however, its source vegetation and climate are much debated. Representatives of the oak family (Fagaceae) were abundant in the Baltic amber source area based on numerous inclusions of staminate inflorescences or individual florets, previously assigned to Castanea and Quercus. However, the actual generic and infrageneric diversity of Fagaceae from Baltic amber remained unknown. Using flower characteristics and section-diagnostic in situ pollen of staminate inflorescences and detached floret inclusions, we describe 18 fossil-species of Fagaceae making this family by far the most diverse plant family preserved in Baltic amber. We substantiate the occurrence of the Castaneoideae, Quercoideae (Quercus sect. Cyclobalanopsis/Lobatae; Q. sect. Lobatae; Q. sect. Protobalanus), Trigonobalanoideae and the extinct genus Eotrigonobalanus. Among the 18 fossil-species, six are described as new: Q. aimeeana, Q. casparyi, Q. multipilosa, E. campanulata, E. conwentzii, E. longianthera; and one new combination is published: Q. brachyandra (≡ Castanea brachyandra). In addition, a lectotype is designated for the name Quercites meyerianus and neotypes are designated for the names Castanea inclusa and Quercus longistaminea (≡ C. longistaminea). Members of the Fagaceae probably inhabited azonal and zonal vegetation types of the amber source area, including bottomland flood-plains and stream banks (Q. sect. Lobatae), dry habitats (Q. sect. Lobatae, Q. sect. Protobalanus), peaty soils, riparian and swamp forests (Castanopsis, Eotrigonobalanus), as well as mixed mesophytic forests (castaneoids, Quercoideae, trigonobalanoids). Affinities to extant North American and E to SE Asian floras support the recent notion that late Eocene Baltic amber (38–34 Ma) was formed in a warm-temperate climate. Citation: Sadowski E.-M., Schmidt A. R. & Denk T. 2020: Staminate inflorescences with in situ pollen from Eocene Baltic amber reveal high diversity in Fagaceae (oak family). – Willdenowia 50: 405–517. doi: https://doi.org/10.3372/wi.50.50303 Version of record first published online on 1 December 2020 ahead of inclusion in December 2020 issue. [ABSTRACT FROM AUTHOR]

Fagaceae is the second-largest woody plant family in Taiwan and has considerable economic and ecological value. Identifying Fagaceae species is essential for forest managers and forestry technical personnel. In this study, ten Fagaceae species were distinguished using image processing and machine learning. For each species, 100 leaf images were collected using flatbed scanners. The morphological, marginal, color, and textural traits of the leaves were then quantified. A genetic algorithm was next applied to identify the traits that are essential for species identification. Support vector machine classifiers were developed to identify the species using the selected traits as the inputs. The results indicated that the proposed approach had an accuracy of 92.8%. [ABSTRACT FROM AUTHOR]

Summary: Fagus hayatae Palibin ex Hayata is illustrated. Its history and distribution in Taiwan and mainland China are discussed. [ABSTRACT FROM AUTHOR]

Quercus acutissima Carruth. is a Chinese important energy plant with high ecological and economic values. While the species chloroplast genome has been reported, its mitochondrial genome (mitogenome) is still unexplored. Here, we assembled and annotated the Q. acutissima mitogenome, and we compared its characteristic differences with several closely related species. The Q. acutissima mitogenome's main structure is branched with three distinguished contigs (linear molecule 1, circular molecule 2, and circular molecule 3) with 448,982 bp total length and 45.72% GC content. The mitogenome contained 51 genes, including 32 protein-coding, 16 tRNA and 3 rRNA genes. We examined codon usage, repeated sequences, genome recombination, chloroplast to mitochondrion DNA transformation, RNA editing, and synteny in the Q. acutissima mitogenome. Phylogenetic trees based on 29 species mitogenomes clarified the species classification. Our results provided comprehensive information of Q. acutissima mitogenome, and they are expected to provide valuable information for Fagaceae evolutionary biology and to promote the species germplasm utilization. [ABSTRACT FROM AUTHOR]

Fungi of the genus Cryphonectria are of special interest to tree pathologists because they cause bark disease in numerous species of the Fagaceae and Betulaceae. Despite this special attention, several Cryphonectria species were not recognized as such for a long time. This also affected the identity of eight isolates with outdated names that have been deposited in our laboratory since 1954. The present study reconstructs the history of the Cryphonectria cultures M282–M289 using primary bibliographic sources. To verify the species identity, all isolates were DNA barcoded and taxonomic affiliation was assessed using a phylogenetic approach. The taxonomic identity combined with the history of the isolates confirms that the chestnut blight epidemic (Cryphonectria parasitica) in Spain was caused by the planting of Asian chestnuts and that the first documented case of bark canker in 1940 was caused by Cryphonectria radicalis on Japanese chestnuts imported from France. The history of isolate M289 could be traced back to CBS 165.32, which proved to be the oldest preserved isolate of the rare Cryphonectria naterciae, confirming the presence of this fungus in Europe for at least 100 years. Based on the ITS barcoding of the 32‐year‐old type specimen, Cryphonectria decipiens must be reclassified as a later synonym of Cryphonectria radicalis. The reconstruction of the history of isolates M282–M289 takes us on a scientific journey from Italy to France, Spain and Portugal in the early twentieth century and offers new insights into the historical context of the invasion of Cryphonectria parasitica in Europe. [ABSTRACT FROM AUTHOR]

Stone oaks, or Lithocarpus species of Fagaceae are ecologically important canopy trees in the tropical and subtropical forests over East Asia, and the fruits of which are important food sources for insects and vertebrates there. The great fruit morphological variation of this genus represents two fruit types, acorn and enclosed receptacle fruit types. However, the evolutionary mechanisms of differentiation into these two fruit types with contrasting morphology remain a puzzle. To reveal the morphogenetic properties of two fruit types, we observed tissue differentiation and development among 20 Lithocarpus species from fruit set to maturity. Unlike in fruits of Quercus, the endocarp differentiation in Lithocarpus fruits occurred later than exocarp and mesocarp. Cupules provided further protection of developing seeds, particularly of acorn-type fruits. Fruits of Lithocarpus and Quercus acorns share similar insect predators. At fruit set, both acorn and enclosed receptacle types were largely identical, with similar tissue morphology and the sequence of differentiation. The distinct difference between two fruit types at maturity came from varied rates and degrees of development between the pericarp and receptacle tissues. We found that heterochrony between two tissues could create substantially divergent ecological strategies for protection and dispersal of their seeds, which is essential for the evolution of two fruit types. [ABSTRACT FROM AUTHOR]

It has been debated whether leaf and stem economics spectra are coordinated across species, because previous studies have provided contradictory results. These studies have been restricted to single biomes, and we hypothesize that climate seasonality may determine the strength of coordination between leaf and stem trait combinations. Herein, using 25 Fagaceae species from East Asia, we investigated the coordination of 16 leaf traits and 5 stem traits across and within three biomes (cool temperate, warm temperate, and tropical forests). The traits were chosen to reflect multiple aspects of plant adaptive strategies, such as water, carbon, and nutrient use. The leaf and stem traits of species that reflect resource-use strategies for different resources were functionally coordinated, forming a single axis of trait variation across biomes. This axis represents the trade-off between fast and slow resource-use strategies. We found the trend that the coordination between leaf and stem traits was the strongest in cool temperate forests after removing two Fagus species, followed by warm temperate forests, but was not observed in tropical forests. Our results support the proposed model that plants vary from slow to fast resource exploitation, using closely related species, and suggest that temperature modulates the coordination of leaf and stem economics spectra. [ABSTRACT FROM AUTHOR]

The Late Oligocene to Early Miocene flora of the Ban Pa Kha Subbasin (Li Basin, northern Thailand) provides a record of montane dry tropical oak-pine forests. The rich ensemble of Fagaceae typical of these forests might have existed in the wider region of Southeast Asia since Eocene times and various fossil plant assemblages represented both lowland (Fagaceae, Dipterocarpaceae) and upland (Fagaceae, Pinaceae) tropical forests. These findings are in conflict with previous interpretations of vegetation development in northern Thailand, which stressed that stratigraphically older (possibly Late Oligocene) spore and pollen assemblages in northern Thailand were markedly different from the modern tropical flora and had a distinct northern temperate character. A major change in climate would have caused a dramatic shift to tropical conditions since the Mid-Miocene. Considering palaeobotanical data from adjacent regions in Southeast Asia, we suggest that differences in spore and pollen assemblages in intermontane basins in northern Thailand are more likely to represent different facies and lowland/upland settings. Assembly of these forest ecosystems, typically comprising Quercus sections Cyclobalanopsis , Ilex and Quercus , pollen of Castaneoideae with affinities to Castanopsis and Lithocarpus , and extinct fagaceous genera such as Eotrigonobalanus , most probably dates back to the Eocene. The absence of oaks of Quercus section Cerris in the spore and pollen assemblage of the Ban Pa Kha Subbasin, despite this group being part of the modern vegetation, might reflect the late arrival (secondary radiation) of this chiefly temperate group in tropical Southeast Asia. [ABSTRACT FROM AUTHOR]

American chestnut (Castanea dentata [Marsh.] Borkh.) was once the dominant hardwood species in Eastern North America before an exotic fungal pathogen, Cryphonectria parasitica (Murrill) Barr, functionally eliminated it across its range. One promising approach toward restoring American chestnut to natural forests is development of blight‐tolerant trees using genetic transformation. However, transformation and related processes can result in unexpected and unintended phenotypic changes, potentially altering ecological interactions. To assess unintended tritrophic impacts of transgenic American chestnut on plant–herbivore interactions, gypsy moth (Lymantria dispar L.) caterpillars were fed leaf disks excised from two transgenic events, Darling 54 and Darling 58, and four control American chestnut lines. Leaf disks were previously treated with an LD50 dose of either the species‐specific Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV) or the generalist pathogen Bacillus thuringiensis subsp. kurstaki (Btk). Mortality was quantified and compared to water blank controls. Tree genotype had a strong effect on the efficacies of both pathogens. Larval mortality from Btk‐treated foliage from only one transgenic event, Darling 54, differed from its isogenic progenitor, Ellis 1, but was similar to an unrelated wild‐type American chestnut control. LdMNPV efficacy was unaffected by genetic transformation. Results suggest that although genetic modification of trees may affect interactions with other nontarget organisms, this may be due to insertion effects, and variation among different genotypes (whether transgenic or wild‐type) imparts a greater change in response than transgene presence. [ABSTRACT FROM AUTHOR]

The palynomorphology of 19 modern species of the genus Quercus L. native to Armenia and adjacent regions, including the Caucasus and Transcaucasia, the Mediterranean region (especially Turkey), as well as Iran, Iraq and Afghanistan, was studied using light microscopy (LM) and scanning electron microscopy (SEM). The work revealed two main types of apertures (3-zonocolpate, 3-zonocolp-porate) as well as six morphological types of pollen based on three main types of exine ornamentation (tuberculate, verrucate, rugulate). We suggest that two main groups of exine ornamentation developed from a common initial type. The first group covers all species of the subgenus Quercus and also Q. suber and Q. alnifolia of the subgenus Heterobalanus. The second group is limited to the morphological type Q. ilex (species Q. ilex, Q. coccifera, subgenus Heterobalanus). On the other hand, the presence of widespread interspecific and introgressive hybridization within the genus Quercus indicates an ongoing process of speciation. This also has an effect on pollen features, which are very similar in a number of species but also vary in individual samples even within the same species. The morphological uniformity of the pollen surface (especially for the subgenus Quercus), the presence of islets of secondary sporopollenin on the surface of pollen grains, as well as orbicules in anthers, do not indicate general primitiveness of representatives of this genus but most likely denote a relatively high degree of speciation activity within this group. [ABSTRACT FROM AUTHOR]

This paper is the fourth part of series that was devoted to the palynological studies of woody plants of Armenia. Investigation of pollen morphology of 14 species of Armenian trees and shrubs from the families Fagaceae L., Grossulariaceae DC. and Hydrangeaceae Dumort. on the level of light (LM) and scanning electron (SEM) microscopes has been carried out. [ABSTRACT FROM AUTHOR]

The anatomical structure of wood is complex and contains considerable information about its specific species, physical properties, growth environment, and other factors. While conventional wood anatomy has been established by systematizing the xylem anatomical features, which enables wood identification generally up to genus level, it is difficult to describe all the information comprehensively. This study apply two computer vision approaches to optical micrographs: the scale-invariant feature transform algorithm and connected-component labelling. They extract the shape and pore size information, respectively, statistically from the whole micrographs. Both approaches enable the efficient detection of specific features of 18 species from the family Fagaceae. Although the methods ignore the positional information, which is important for the conventional wood anatomy, the simple information on the shape or size of the elements is enough to describe the species-specificity of wood. In addition, according to the dendrograms calculated from the numerical distances of the features, the closeness of some taxonomic groups is inconsistent with the types of porosity, which is one of the typical classification systems for wood anatomy, but consistent with the evolution based on molecular phylogeny; for example, ring-porous group Cerris and radial-porous group Ilex are nested in the same cluster. We analyse which part of the wood structure gave the taxon-specific information, indicating that the latewood zone of group Cerris is similar to the whole zone of group Ilex. Computer vision approaches provide statistical information that uncovers new aspects of wood anatomy that have been overlooked by conventional visual inspection. [ABSTRACT FROM AUTHOR]