Richard Buggs

Queen Mary, University of London | QMUL · School of Biological and Chemical Sciences

Ash trees (genus Fraxinus, family Oleaceae) are widespread throughout the Northern Hemisphere, but are being devastated in Europe by the fungus Hymenoscyphus fraxineus, causing ash dieback, and in North America by the herbivorous beetle Agrilus planipennis. Here we sequence the genome of a low-heterozygosity Fraxinus excelsior tree from Gloucesters...

New sequencing technologies allow development of genome-wide markers for any genus of ecological interest, including plant genera such as Betula (birch) that have previously proved difficult to study due to widespread polyploidy and hybridization. We present a de novo reference genome sequence assembly, from 66× short read coverage, of Betula nana...

Hybrid zones are 'natural laboratories' for studying the origin, maintenance and demise of species. Theory predicts that hybrid zones can move in space and time, with significant consequences for both evolutionary and conservation biology, though such movement is often perceived as rare. Here, a review of empirical studies of moving hybrid zones in...

Background and aims: BetulaL. (birch) is a genus of approx. 60 species, subspecies or varieties with a wide distribution in the northern hemisphere, of ecological and economic importance. A new classification ofBetulahas recently been proposed based on morphological characters. This classification differs somewhat from previously published molecul...

Clonal propagation enables favourable crop genotypes to be rapidly selected and multiplied. However, the absence of sexual propagation can lead to low genetic diversity and accumulation of deleterious mutations, which may eventually render crops less resilient to pathogens or environmental change. To better understand this trade-off, we characteriz...

Disentangling the numerous processes that affect patterns of genome‐wide diversity in widespread tree species has important implications for taxonomy, conservation, and forestry. Here, we investigate the population genomic structure of Asian white birch (Betula platyphylla) in China and seek to explain it in terms of hybridization, demography and a...

In a From the Cover article in this issue of Molecular Ecology, Ashraf et al. (2022) apply genomic prediction methods, devised by breeders to inform artificial selection, to understand the genetic component of variation in highly polygenic quantitative traits in Soay sheep (Figure 1). These methods have allowed them to investigate the effects of co...

The holm oak (Quercus ilex L.) is the most representative species of the Mediterranean Basin and the agrosilvopastoral Spanish "dehesa" ecosystem. Being part of our life, culture, and subsistence since ancient times, it has great environmental and economic importance. More recently, there has been a renewed interest in using the Q. ilex acorn as a...

27 • Crop diversity plays a major role in underpinning food security. It is especially important to 28 smallholder and subsistence farmers, who often rely on crop diversity for stable and resilient 29 production. Despite this, global expansion of a small pool of major crops and the associated 30 homogenisation of global agricultural systems may dec...

Clonal propagation enables favourable crop genotypes to be rapidly selected and multiplied. However, the absence of sexual propagation can lead to low genetic diversity and accumulation of deleterious mutations, which may eventually render crops less resilient to pathogens or environmental change. To better understand this trade-off, we characteris...

Evolutionary responses to sudden changes in the environment can, in theory, be rapid if they involve small shifts in allele frequencies at many loci. Such adaptation has proven hard to characterise in wild populations. We overcome these problems, in quantifying the genetic response of European ash trees ( Fraxinus excelsior ) to the strong selectiv...

Disentangling the numerous processes that affect patterns of genome-wide diversity in widespread tree species has important implications for taxonomy, conservation, and forestry. Here, we investigate the population genomic structure of Asian white birch (Betula platyphylla) in China and seek to explain it in terms of hybridization, demography and a...

The fungal genus Fusarium (Ascomycota) includes well-known plant pathogens that are implicated in diseases worldwide, and many of which have been genome sequenced. The genus also encompasses other diverse lifestyles, including species found ubiquitously as asymptomatic-plant inhabitants (endophytes). Here, we produced structurally annotated genome...

Crop diversity plays a major role in underpinning food security. It is especially important to smallholder and subsistence farmers, who often rely on crop diversity for stable and resilient production. Despite this, global expansion of a small pool of major crops and the associated homogenisation of global agricultural systems may decrease on-farm...

New evidence that a mid-Cretaceous fossil represents a modern angiosperm genus partly reinstates Darwin’s view of the fossil record.

Acute Oak Decline (AOD) is complex syndrome affecting Britain’s keystone native oak species, (Quercus robur L. and Q. petraea L. (Matt.) Liebl.), in some cases causing mortality within five years of symptom development. The most distinguishable symptom is weeping stem lesions, from which four species of bacteria have been isolated: Brenneria goodwi...

Tree ring features are affected by environmental factors and therefore are the basis for dendrochronological studies to reconstruct past environmental conditions. Oak wood often provides the data for these studies because of the durability of oak heartwood and hence the availability of samples spanning long time periods of the distant past. Wood fo...

Green ash (Fraxinus pennsylvanica) is the most widely distributed ash tree in North America. Once common, it has experienced high mortality from the non‐native invasive emerald ash borer (EAB; Agrilus planipennis). A small percentage of native green ash trees that remain healthy in long‐infested areas, termed “lingering ash,” display partial resist...

Acute Oak Decline (AOD) is complex syndrome affecting Britain’s keystone native oak species, (Quercus robur L. and Q. petraea L. (Matt.) Liebl.), in some cases causing mortality within five years of symptom development. The most distinguishable symptom is weeping stem lesions, from which four species of bacteria have been isolated: Brenneria goodwi...

The largest populations of veteran oak trees in Europe are found in British parklands: managed wood pastures up to 1000 years old. Here, we present genomic evidence that parkland oak populations harbour considerable diversity and grew from local seed sources. We found some evidence for natural regeneration of offspring and for hybridization between...

Digitized molecular data are vital to numerous aspects of scientific research and genetic resource use. The Convention on Biological Diversity currently refers to this as “Digital Sequence Information” (DSI), a term not widely adopted by science and lacking a clear definition. There are concerns over the access to genetic resources and absence of b...

Tree ring features are affected by environmental factors and therefore are the basis for dendrochronological studies to reconstruct past environmental conditions. Oak wood often provides the data for these studies because of the durability of oak heartwood and hence the availability of samples spanning long time periods of the distant past. Wood fo...

European hazelnut (Corylus avellana) is a diploid (2n = 22), monecious and wind-pollinated species, extensively cultivated for its nuts. Turkey is the world-leading producer of hazelnut, supplying 70–80% of the world’s export capacity. Hazelnut is mostly grown in the Black Sea Region, and maintained largely through clonal propagation. Understanding...

The two predominant oak species in Britain are Quercus robur (English or pedunculate oak) and Q. petraea (sessile oak). We sequenced the whole genomes of 386 oak trees from four British parkland sites and found over 50 million nuclear single nucleotide polymorphisms (SNPs), allowing us to identify 360 Q. robur, ten Q. petraea and 16 hybrid individu...

In rapidly changing environments species conservation can be hindered by uncertainties in distinguishing closely related species. Cryptic ongoing hybridization can add further uncertainty and could be beneficial or destructive. Here, we show that a declining birch tree species is hybridizing with a more widespread relative in the Junggar basin, NW...

Numerous plant genera have a history including frequent hybridisation and polyploidisation (allopolyploidisation), which means that their phylogeny is a network of reticulate evolution that cannot be accurately depicted as a bifurcating tree with a single tip per species. The genus Betula, which contains many ecologically important tree species, is...

The phrase "Darwin's abominable mystery" is frequently used with reference to a range of outstanding questions about the evolution of the plant group today known as the angiosperms. Here, I seek to more fully understand what prompted Darwin to coin the phrase in 1879, and the meaning he attached to it, by surveying the systematics, paleobotanical r...

European hazelnut (Corylus avellana L.) is a tree crop of economic importance worldwide, but especially to northern Turkey, where the majority of production takes place. Hazelnut production is currently challenged by environmental stresses such as a recent outbreak of severe powdery mildew disease; furthermore, allergy to hazelnuts is an increasing...

Papers from the labs of Peter Holland and Jordi Paps investigate patterns of gene presence and absence in plants and animals. Their studies lead to the surprising finding that novel genes do not accumulate with Darwinian gradualism in the phylogeny. The authors describe bursts of innovation with novel gene gains, massive gene losses, and frequent h...

Recent studies show that molecular convergence plays an unexpectedly common role in the evolution of convergent phenotypes. We exploited this phenomenon to find candidate loci underlying resistance to the emerald ash borer (EAB, Agrilus planipennis), the United States’ most costly invasive forest insect to date, within the pan-genome of ash trees (...

Numerous plant genera have a history including frequent hybridisation and polyploidisation, which often means that their phylogenies are not yet fully resolved. The genus Betula , which contains many ecologically important allopolyploid tree species, is a case in point. We generated genome-wide sequence data for 27 diploid and 31 polyploid Betula s...

Molecular markers can allow us to differentiate species that occupy a morphological continuum, and detect patterns of allele sharing that can help us understand the dynamics of geographic zones where they meet. Betula microphylla is a declining wetland species in NW China that forms a continuum of leaf morphology with its relative Betula tianshanic...

Researchers seldom look at naked genome assemblies: instead the attributes of DNA sequences are mediated through statistics, annotations and high level summaries. Here we present software that visualizes the bare sequences of whole genome assemblies in a zoomable interface. This can assist in detection of chromosome architecture and contamination b...

Hazelnut is consumed worldwide and is of critical economic importance to the rural communities of Turkey's northern coast. A new disease outbreak has drastically decreased yields across Turkey and climate change is emerging as a new threat to cultivation. Our study is the first to provide a genomic perspective on diversity in this vulnerable crop,...

When populations of a rare species are small, isolated and declining under climate change, some populations may become locally maladapted. Detecting this maladaptation may allow effective rapid conservation interventions, even if based on incomplete knowledge. Population maladaptation may be estimated by finding genome‐environment associations (GEA...

Plants are threatened in a globalised world because people are transporting pests and pathogens around the planet at unprecedented rates. Natural resistance to pests and pathogens has never been more important. In this special issue of Plants, People, Planet we focus on resistance found in tree populations. This has long been a neglected area of re...

Populations of European ash trees (Fraxinus excelsior) are being devastated by the invasive alien fungus Hymenoscyphus fraxineus, which causes ash dieback. We sequenced whole genomic DNA from 1,250 ash trees in 31 DNA pools, each pool containing trees with the same ash dieback damage status in a screening trial and from the same seed-source zone. A...

Closely related species with a worldwide distribution provide an opportunity to understand evolutionary and biogeographic processes at a global scale. Hazel (Corylus) is an economically important genus of tree and shrub species found in temperate regions of Asia, North America and Europe. Here we use multiple nuclear and chloroplast loci to estimat...

European ash is a significant tree commercially, ecologically, and culturally. It is currently threatened by two invasive species, the fungus that causes ash dieback and the emerald ash borer (EAB) beetle. We show that saplings of European ash are much less susceptible to EAB than black ash, which has suffered severe damage in North America, but ha...

European hazelnut ( Corylus avellana L.) is a tree crop of economic importance worldwide, but especially to northern Turkey, where the majority of production takes place. Hazelnut production is currently challenged by environmental stresses such as a recent outbreak of severe powdery mildew disease; furthermore, allergy to hazelnuts is an increasin...

Genome-wide discovery of candidate genes for functional traits within a species typically involves the sequencing of large samples of phenotyped individuals, or linkage analysis through multiple generations. When a trait occurs repeatedly among phylogenetically independent lineages within a genus, a more efficient approach may be to identify genes...

When populations of a rare species are small, isolated and declining under climate change, some populations may become locally maladapted. Detecting this maladaptation may allow effective rapid conservation interventions, even if based on incomplete knowledge. Population maladaptation may be estimated by finding genome-environment associations (GEA...

The current ash dieback epidemic in Europe caused by Hymenoscyphus fraxineus poses a key question to policy makers: whether or not to commit time and resources to the initiation of a breeding programme for the development of more resistant ash, as a long-term policy of adaptation to the epidemic. Here we review current evidence on the potential via...

Background and aims: Differences in local abundance and ploidy level are predicted to impact the direction of introgression between species. Here, we tested these hypotheses on populations of Betula albosinensis (red birch) and Betula platyphylla (white birch) which were thought to differ in ploidy level, the former being tetraploid and the latter...

Populations of European ash trees ( Fraxinus excelsior ) are being devastated by the invasive alien fungus Hymenoscyphus fraxineus , which causes ash dieback (ADB). We sequenced whole genomic DNA from 1250 ash trees in 31 DNA pools, each pool containing trees with the same ADB damage status in a screening trial and from the same seed-source zone. A...

Assessing and describing genetic diversity in crop plants is a crucial first step towards their improvement. The European hazelnut, Corylus avellana , is one of the most economically important tree nut crops worldwide. It is primarily produced in Turkey where rural communities depend on it for their livelihoods. Despite this we know little about ha...

Damage to ash trees by ash dieback caused by the emerging fungal pathogen Hymenoscyphus fraxineus is impacting people across Europe. This poses challenges to: public safety; productivity of commercial forestry; green spaces and human wellbeing; and ecosystem services and carbon sequestration. Here, we seek to quantify the impact of ash dieback on t...

Dwarf birch (Betula nana) has a widespread boreal distribution but has declined significantly in Britain where populations are now highly fragmented. We analyzed the genetic diversity of these fragmented populations using markers that differ in mutation rate: conventional microsatellites markers (PCR-SSRs), RADseq generated transition and transvers...

Background: European ash trees (Fraxinus excelsior) are currently threatened by ash dieback (ADB) caused by the fungus Hymenoscyphus fraxineus but a small percentage of the population possesses natural low susceptibility. The genome of a European ash tree has recently been sequenced. Here, we present whole genome DNA methylation data for two F. ex...

Pests and pathogens are an increasing threat to trees and forests, and the associated biodiversity and ecosystem services. Producing trees that are resistant to such threats is frequently emphasized by policymakers across Europe and North America. However, there are several approaches for developing and deploying resistant trees, and the process ca...

European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility a...

Ash dieback (ADB), caused by Hymenoscyphus fraxineus, has severely damaged a large proportion of ash trees (Fraxinus excelsior) in continental Europe. We have little damage data for the British Isles where the disease was found only five years ago in the Southeast, and is still spreading. A large-scale screening trial to evaluate ADB damage to prov...

To the Editor — In 1879 in a private letter to Joseph Hooker, Charles Darwin grumbled 1 : “The rapid development as far as we can judge of all the higher plants within recent geological times is an abominable mystery.”Although this abominable mystery is often cited today, and sometimes declared solved, few realize that the mystery is deeper today t...

Genome sequence assemblies of many angiosperm trees used in forestry are now emerging, in addition to the well-characterised genomes of black poplar and eucalyptus reviewed in previous chapters of this book. Whilst the number of published genomes of angiosperm forest trees lags behind that of angiosperm trees grown commercially for fruit or nuts, m...

Table S1 Detailed information about and results of samples used in this study. Table S2 Parameter settings and version numbers for the CLC tools used in the present analyses. Table S3 Change in number of SNVs with different coverage thresholds being applied to the data set during the genotyping. Fig. S1 Flow chart outlining the analysis pipeline...

Hybridisation may lead to introgression of genes among species. Introgression may be bidirectional or unidirectional, depending on factors such as the demography of the hybridising species, or the nature of reproductive barriers between them. Previous microsatellite studies suggested bidirectional introgression between diploid Betula nana (dwarf bi...

Tree disease epidemics are a global problem, impacting food security, biodiversity and national economies. The potential for conservation and breeding in trees is hampered by complex genomes and long lifecycles, with most species lacking genomic resources. The European Ash tree Fraxinus excelsior is being devastated by the fungal pathogen Hymenoscy...