Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
219
result(s) for
"Fay, Michael F"
Sort by:
The genus tulipa : tulips of the world
'The Genus Tulipa' is a complete survey of tulip species to date. Each species is illustrated by a botanical painting by artist and author Diana Everett, with accompanying colour photographs of the plants in habitat and distribution maps.
Book
Orchid conservation: how can we meet the challenges in the twenty-first century?
With c. 28,000 species, orchids are one of the largest families of flowering plants, and they are also one of the most threatened, in part due to their complex life history strategies. Threats include habitat destruction and climate change, but many orchids are also threatened by unsustainable (often illegal and/or undocumented) harvest for horticulture, food or medicine. The level of these threats now outstrips our abilities to combat them at a species-by-species basis for all species in such a large group as Orchidaceae; if we are to be successful in conserving orchids for the future, we will need to develop approaches that allow us to address the threats on a broader scale to complement focused approaches for the species that are identified as being at the highest risk.
Journal Article
Barcoding of Plants and Fungi
DNA barcoding enables rapid and accurate identification of species in many groups of organisms, but cannot always distinguish between closely related species of land plants or fungi. Rapid identification of biological specimens or fragments of biological origin has always been desirable, but has rarely been possible owing to a shortage of natural history specialists. Very often, for a particular group of organisms there is only one expert worldwide, and no one person can be expected to identify every organism that is relevant to ecological studies. Also, environmental samples (for example, from water or soil) that contain mixtures of minute organisms with few morphological traits pose great identification challenges. Short, standardized DNA regions—or “barcodes”—have been used to identify biological material from many groups of animals ( 1 – 3 ). The barcoding approach also has great potential for identifying plants ( 4 , 5 ) and fungi ( 6 ), but faces different challenges when applied to these groups.
Journal Article
A universe of dwarfs and giants: genome size and chromosome evolution in the monocot family Melanthiaceae
Since the occurrence of giant genomes in angiosperms is restricted to just a few lineages, identifying where shifts towards genome obesity have occurred is essential for understanding the evolutionary mechanisms triggering this process.
Genome sizes were assessed using flow cytometry in 79 species and new chromosome numbers were obtained. Phylogenetically based statistical methods were applied to infer ancestral character reconstructions of chromosome numbers and nuclear DNA contents.
Melanthiaceae are the most diverse family in terms of genome size, with C-values ranging more than 230-fold. Our data confirmed that giant genomes are restricted to tribe Parideae, with most extant species in the family characterized by small genomes. Ancestral genome size reconstruction revealed that the most recent common ancestor (MRCA) for the family had a relatively small genome (1C = 5.37 pg). Chromosome losses and polyploidy are recovered as the main evolutionary mechanisms generating chromosome number change.
Genome evolution in Melanthiaceae has been characterized by a trend towards genome size reduction, with just one episode of dramatic DNA accumulation in Parideae. Such extreme contrasting profiles of genome size evolution illustrate the key role of transposable elements and chromosome rearrangements in driving the evolution of plant genomes.
Journal Article
Rapid Parallel Adaptation to Anthropogenic Heavy Metal Pollution
The impact of human-mediated environmental change on the evolutionary trajectories of wild organisms is poorly understood. In particular, capacity of species to adapt rapidly (in hundreds of generations or less), reproducibly and predictably to extreme environmental change is unclear. Silene uniflora is predominantly a coastal species, but it has also colonized isolated, disused mines with phytotoxic, zinc-contaminated soils. To test whether rapid, parallel adaptation to anthropogenic pollution has taken place, we used reduced representation sequencing (ddRAD) to reconstruct the evolutionary history of geographically proximate mine and coastal population pairs and found largely independent colonization of mines from different coastal sites. Furthermore, our results show that parallel evolution of zinc tolerance has occurred without gene flow spreading adaptive alleles between mine populations. In genomic regions where signatures of selection were detected across multiple mine-coast pairs, we identified genes with functions linked to physiological differences between the putative ecotypes, although genetic differentiation at specific loci is only partially shared between mine populations. Our results are consistent with a complex, polygenic genetic architecture underpinning rapid adaptation. This shows that even under a scenario of strong selection and rapid adaptation, evolutionary responses to human activities (and other environmental challenges) may be idiosyncratic at the genetic level and, therefore, difficult to predict from genomic data.
Journal Article
Analysis of the giant genomes of Fritillaria (Liliaceae) indicates that a lack of DNA removal characterizes extreme expansions in genome size
Plants exhibit an extraordinary range of genome sizes, varying by > 2000-fold between the smallest and largest recorded values. In the absence of polyploidy, changes in the amount of repetitive DNA (transposable elements and tandem repeats) are primarily responsible for genome size differences between species. However, there is ongoing debate regarding the relative importance of amplification of repetitive DNA versus its deletion in governing genome size.
Using data from 454 sequencing, we analysed the most repetitive fraction of some of the largest known genomes for diploid plant species, from members of Fritillaria.
We revealed that genomic expansion has not resulted from the recent massive amplification of just a handful of repeat families, as shown in species with smaller genomes. Instead, the bulk of these immense genomes is composed of highly heterogeneous, relatively low-abundance repeat-derived DNA, supporting a scenario where amplified repeats continually accumulate due to infrequent DNA removal.
Our results indicate that a lack of deletion and low turnover of repetitive DNA are major contributors to the evolution of extremely large genomes and show that their size cannot simply be accounted for by the activity of a small number of high-abundance repeat families.
Journal Article
Plant Genome Size Is Associated With Fine‐Scale Spatial Variation in Soil Depth, but Not Climatic Conditions, in the Grass Festuca ovina
Genome size varies among individuals within plant species and their populations. Interspecific variation in plant genome size is associated with phenology, climate, and latitude and longitude—suggesting that genome size may be linked with environmental adaptation—but the evolutionary significance of intraspecific variation in genome size remains unresolved. In particular, little is known regarding how selection under different climatic and micro‐environmental conditions shapes intraspecific variation in genome size. We measured genome size within Festuca ovina populations collected from grassland plots exposed to 16 years of experimental drought treatment at the Buxton Climate Change Impacts Laboratory. We assessed whether genome size was associated with either drought treatment or fine‐scale heterogeneity in soil depth within grassland plots. Genome size varied by up to 1.28‐fold among F. ovina individuals, but was not associated with either drought treatment or plant phenotypes (cell size, flowering time, and biomass). Genome size was, however, negatively associated with fine‐scale variation in soil depth, implying that abiotic and biotic conditions linked with soil depth impose either direct or indirect selection on genome size. We suggest that the higher nutrient availability and reduced competition associated with shallow soils enable individuals with larger genomes to persist locally within the grassland. Intraspecific variation in plant genome size could allow adaptation to changing environmental conditions. Using the world's longest running drought manipulation experiment, we make a long‐term experimental test of the relationship between population‐level plant genome size and drought. We show that while plant genome size is not altered by drought treatment, it is associated with fine‐scale natural heterogeneity in soil depth.
Journal Article
Lost and Found: Coffea stenophylla and C. affinis, the Forgotten Coffee Crop Species of West Africa
(Arabica) and
(robusta) almost entirely dominate global coffee production. Various challenges at the production (farm) level, including the increasing prevalence and severity of disease and pests and climate change, indicate that the coffee crop portfolio needs to be substantially diversified in order to ensure resilience and sustainability. In this study, we use a multidisciplinary approach (herbarium and literature review, fieldwork and DNA sequencing) to elucidate the identity, whereabouts, and potential attributes, of two poorly known coffee crop species:
and
. We show that despite widespread (albeit small-scale) use as a coffee crop species across Upper West Africa and further afield more than 100 years ago, these species are now extremely rare in the wild and are not being farmed. Fieldwork enabled us to rediscover
in Sierra Leone, which previously had not been recorded in the wild there since 1954. We confirm that
is an indigenous species in Guinea, Sierra Leone, and Ivory Coast.
was discovered in the wild in Sierra Leone for the first time, having previously been found only in Guinea and Ivory Coast. Prior to our rediscovery,
was last seen in the wild in 1941, although sampling of an unidentified herbarium specimen reveals that it was collected in Guinea-Conakry in 2015. DNA sequencing using plastid and ITS markers was used to: (1) confirm the identity of museum and field collected samples of
; (2) identify new accessions of
; (3) refute hybrid status for
; (4) identify accessions confused with
; (5) show that
and
are closely related, and possibly a single species; (6) substantiate the hybrid
×
; (7) demonstrate the use of plastid and nuclear markers as a simple means of identifying F1 and early-generation interspecific hybrids in
; (8) infer that
is not monophyletic; and (9) show that hybridization is possible across all the major groups of key Africa
species (Coffee Crop Wild Relative Priority Groups I and II).
and
may possess useful traits for coffee crop plant development, including taste differentiation, disease resistance, and climate resilience. These attributes would be best accessed via breeding programs, although the species may have niche-market potential via minimal domestication.
Journal Article
Hybrid speciation in angiosperms: parental divergence drives ploidy
Hybridization and polyploidy are now hypothesized to have regularly stimulated speciation in angiosperms, but individual or combined involvement of these two processes seems to involve significant differences in pathways of formation, establishment and evolutionary consequences of resulting lineages. We evaluate here the classical cytological hypothesis that ploidy in hybrid speciation is governed by the extent of chromosomal rearrangements among parental species. Within a phylogenetic framework, we calculate genetic divergence indices for 50 parental species pairs and use these indices as surrogates for the overall degree of genomic divergence (that is, as proxy for assessments of dissimilarity of the parental chromosomes). The results confirm that genomic differentiation between progenitor taxa influences the likelihood of diploid (homoploid) versus polyploid hybrid speciation because genetic divergence between parents of polyploids is found to be significantly greater than in the case of homoploid hybrid species. We argue that this asymmetric relationship may be reinforced immediately after hybrid formation, during stabilization and establishment. Underlying mechanisms potentially producing this pattern are discussed.
Journal Article