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1.
The identification of field mice Apodemus flavicollis, Apodemus sylvaticus, and Apodemus alpicola represents a challenge for field scientists due to their highly overlapping morphological traits and habitats. Here, we propose a new fast real‐time PCR method to discriminate the three species by species‐specific TaqMan assays. Primers and probes were designed based on the alignment of 54 cyt‐b partial sequences from 25 different European countries retrieved from GenBank. TaqMan assays were then tested on 133 samples from three different areas of Italy. Real‐time PCR analysis showed 92 samples classified as A. flavicollis, 13 as A. sylvaticus, and 28 as A. alpicola. We did not observe any double amplification and DNA sequencing confirmed species assignment obtained by the TaqMan assays. The method is implementable on different matrices (ear tissues, tail, and blood). It can be used on dead specimens or on alive animals with minimally invasive sampling, and given the high sensitivity, the assay may be also suitable for degraded or low‐DNA samples. The method proved to work well to discriminate between the species analyzed. Furthermore, it gives clear results (amplified or not) and it does not require any postamplification handling of PCR product, reducing the time needed for the analyses and the risk of carryover contamination. It therefore represents a valuable tool for field ecologists, conservationists, and epidemiologists.  相似文献   

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The genus Ptilophora currently includes 16 species occurring mostly in subtidal habitats of the Indo‐Pacific Ocean, but its global diversity and biogeography are poorly understood. We analyzed mitochondrial cox1, plastid rbcL and plastid psbA sequences from specimens collected in southern Madagascar during the 2010 Atimo Vatae expedition and studied their morphologies. Both morphological and molecular data sets demonstrated the presence of five species in southern Madagascar: Ptilophora hildebrandtii, P. pterocladioides, and three new species described here, P. aureolusa, P. malagasya, and P. spongiophila. Ptilophora aureolusa is distinguished by its compound pinnae with uniformly spaced pinnules. Ptilophora malagasya has an indistinct midrib and irregularly spaced pinnules. Ptilophora spongiophila, heavily coated with sponges, has cylindrical to flattened main axes, lateral and surface proliferations, and spatulate tetrasporangial sori. The species of Ptilophora found in Madagascar are endemic, except P. hildebrandtii, which also occurs in eastern Africa. Ptilophora comprises four phylogenetic groups that map to eastern Australia, Japan, western Australia/Southeast Asia/Madagascar/eastern Africa, and Madagascar/eastern Africa/Aegean Sea. Biogeographical analysis revealed that the ancestor of Ptilophora originated in Australia, but most of the species radiated from Madagascar.  相似文献   

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Miscanthus is a rhizomatous C4 grass of great interest as a biofuel crop because it has the potential to produce high yields over a wide geographical area with low agricultural inputs on marginal land less suitable for food production. At the moment, a clonal interspecific hybrid Miscanthus × giganteus is the most widely cultivated and studied in Europe and the United States, but breeding programmes are developing newer more productive varieties. Here, we quantified the physiological processes relating to whole season yield in a replicated plot trial in Wales, UK. Light capture and conversion efficiency were parameterized for four carefully selected genotypes (M. sinensis, M. sacchariflorus and Miscanthus × giganteus). Differences in the canopy architecture in mature stands as measured by the extinction coefficient (k) were small (0.55–0.65). Sensitivity analysis on a mathematical model of Miscanthus was performed to quantify the accumulative intercepted photosynthetically active radiation (iPAR) in the growing season using (i) k, (ii) variation in the thermal responses of leaf expansion rate, (iii) base temperature for degree days and (iv) date start of canopy expansion. A 10% increase in k or leaf area per degree day both had a minimal effect on iPAR (3%). Decreasing base temperature from 10 to 9 °C gave an 8% increase in iPAR. If the starting date for canopy expansion was the same as shoot emergence date, then the iPAR increases by 12.5%. In M. × giganteus, the whole season above ground and total (including below ground) radiation‐use efficiency (RUE) ranged from 45% to 37% higher than the noninterspecific hybrid genotypes. The greater yields in the interspecific hybrid M. × giganteus are explained by the higher RUE and not by differences in iPAR or partitioning effects. Studying the mechanisms underlying this complex trait could have wide benefits for both fuel and food production.  相似文献   

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Hybridization of introduced domesticates and closely related natives is well documented in annual crops. The widespread introduction of the domesticated grapevine, Vitis vinifera, into California where it overlaps with two native congenerics, with which it is interfertile, provides opportunity to investigate hybridization between woody perennials. Although geographically widespread, the introduction over the past two centuries has been limited to a few elite clonal cultivars, providing a unique opportunity to study the effects of hybridization on the native species. The amount of hybridization with V. vinifera and the genetic diversity of wild‐growing Vitis californica and Vitis girdiana were examined using nineteen microsatellite markers. STRUCTURE analysis was used to define hybrid and introgressed individuals and to analyze genetic structure of the native species. FAMOZ software was used to identify which V. vinifera cultivars served as parents of F1 hybrids. The three species were clearly distinguished by STRUCTURE analysis. Thirty percent of 119 V. californica vines were hybrids. The domesticated parent was identified for 16 F1 hybrid vines; the original California cultivar, ‘Mission’, was the parent of eight. Backcrosses were also found, showing introgression into subsequent generations. Similar results were obtained for a small sample of V. girdiana. Removing hybrids greatly reduced the genetic variation of the presumed pure species, among which there was essentially no genetic structure. Limited genetic variability indicates the California natives may be threatened by genetic erosion. The discovery of F1 hybrids of ‘Mission’, a cultivar not grown in the areas for ~100 years, suggests long generation times for wild vines that, often, grow into expansive liana and propagate by layering, all factors that limit recruitment in populations already disjunct by habitat lose. Hermaphroditic flowers and fruit that is more attractive to birds may favor the production of backcross seed and establishment of introgressed individuals.  相似文献   

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The phylogeny of ligulate and sulfuric‐acid containing species of Desmarestia, occurring worldwide from polar to temperate regions, was revised using a multigenic and polyphasic approach. Sequence data, gametophyte characteristics, and sporophyte morphology support reducing a total of 16 taxa to four different species. (1) D. herbacea, containing broad‐bladed and highly branched forms, has dioecious gametophytes. The three other species have monoecious gametophytes: (2) D. ligulata which is profusely branched and, except for one subspecies, narrow‐bladed, (3) Japanese ligulate Desmarestia, here described as D. japonica sp. nov., which is morphologically similar to D. ligulata but genetically distant from all other ligulate taxa. This species may have conserved the morphology of original ligulate Desmarestia. (4) D. dudresnayi, including unbranched or little branched broad‐bladed taxa. A figure of the holotype of D. dudresnayi, which was lost for decades, was relocated. The taxonomy is complemented by a comparison of internal transcribed spacer and cytochrome c oxidase subunit I (cox1) as potential barcode loci, with cox1 offering good resolution, reflecting species delimitations within the genus Desmarestia.  相似文献   

7.
Summary.  The hybrid hazel, Corylus  ×  vilmorinii Rehder is described and illustrated. Its robust habit and showy catkins make it an interesting and worthwhile tree to cultivate.  相似文献   

8.
Summary.  Quercus × warburgii A. Camus, the Cambridge Oak, is a semi‐evergreen tree of hybrid origin, possibly between Q. rugosa Née and Q. robur L., and is only known in cultivation. Mature trees in gardens are extremely rare. Its history and cultivation are discussed.  相似文献   

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《Médecine Nucléaire》2023,47(3):120-130
Bone scintigraphy is a nuclear imaging scan using a radiopharmaceutical composed of a bisphosphonate coupled to a radionuclide (technetium 99 m). Radiopharmaceutical uptake is particularly important at the level of the bone structures having a strong osteoblastic activity. These uptakes can be due to a benign pathology (fracture, loosening of prosthesis, rheumatic pathologies, etc.) or to a malignant pathology (primary or secondary bone lesion). The high sensitivity of bone scintigraphy makes it particularly interesting at the initial stage of the pathology, especially when x-rays are normal. In addition, its specificity has clearly improved in recent years with the increasingly use of tomoscintigraphy coupled with X-ray scanning (SPECT/CT). We describe the operating principle of bone scintigraphy, normal uptakes with its variants as well as pathological uptake features in traumatic, rheumatic, prosthetic or cancerous pathologies.  相似文献   

11.
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is the most devastating wheat disease in China. Early and accurate detection of the pathogens would facilitate effective control of the diseases. DNA‐based methods now provide essential tools for accurate plant disease diagnosis. In this study, inter‐simple sequence repeats (ISSR) technique has been successfully applied to develop a sequence‐characterized amplified region (SCAR) marker for diagnosis of stripe rust of wheat and detection of Pst. In this study, one fragment unique to Pst was identified by ISSR and then sequenced. Based on the specific fragment, a pair of SCAR primers (616AF/616AR) was designed to amplify a 299‐bp DNA fragment within the sequenced region. The primers can amplify a unique DNA fragment for all tested isolates of Pst but not for the other pathogens of wheat leaves and the uninfected leaves. The polymerase chain reaction (PCR) assay could detect as low as 0.1 ng of genomic DNA in a 25.0 μl PCR reaction mixture and detect the pathogen from asymptomatic wheat leaves inoculated with Pst under glasshouse conditions.  相似文献   

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Summary.  Rosa 'Cantabrigiensis' is a hybrid whose history is connected with Cambridge University Botanic Garden where it was raised and first recognised in 1922. Its origin in the experimental work on Rosa by Charles Hurst is discussed, and its likely parentage is given.  相似文献   

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Plant communities are not stable over time and biological novelty is predicted to emerge due to climate change, the introduction of exotic species and land‐use change. However, the rate at which this novelty may arise over longer time periods has so far received little attention. We reconstruct the emergence of novelty in Europe for a set of baseline conditions over the past 15 000 years to assess past rates of emergence and investigate underlying causes. The emergence of novelty is baseline specific and, during the early‐Holocene, was mitigated by the rapid spread of plant taxa. Although novelty generally increases as a function of time, climate and human‐induced landscape changes contributed to a non‐linear post‐glacial trajectory of novelty with jumps corresponding to periods of rapid changes. Emergence of novelty accelerated during the past 1000 years. Historical cultural landscapes experienced a faster novelty development due to the contribution from anthropogenic land‐cover changes.  相似文献   

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Nine polymorphic microsatellite loci were identified in the tropical plant Vasconcellea ×heilbornii and used to estimate allelic diversity in two populations of southern Ecuador. Allelic richness ranged from two to five alleles, observed heterozygosity ranged from 0.150 to 0.947 and expected heterozygosity ranged from 0.186 to 0.701. Most of these markers also amplified microsatellite loci in two other Vasconcellea species (Vasconcellea stipulata and Vasconcellea cundinamarcensis). Hence, these markers will be useful for population genetic analysis and the evaluation of genetic diversity and gene flow in these species.  相似文献   

19.
The importance of speciation‐with‐geneflow scenarios is increasingly appreciated. However, the specific processes and the resulting genomic footprints of selection are subject to much discussion. We studied the genomics of speciation between the two panmictic, sympatrically spawning sister species; European (Anguilla anguilla) and American eel (A. rostrata). Divergence is assumed to have initiated more than 3 Ma, and although low gene flow still occurs, strong postzygotic barriers are present. Restriction‐site‐associated DNA (RAD) sequencing identified 328 300 SNPs for subsequent analysis. However, despite the presence of 3757 strongly differentiated SNPs (FST > 0.8), sliding window analyses of FST showed no larger genomic regions (i.e. hundreds of thousands to millions of bases) of elevated differentiation. Overall FST was 0.041, and linkage disequilibrium was virtually absent for SNPs separated by more than 1000 bp. We suggest this to reflect a case of genomic hitchhiking, where multiple regions are under directional selection between the species. However, low but biologically significant gene flow and high effective population sizes leading to very low genetic drift preclude accumulation of strong background differentiation. Genes containing candidate SNPs for positive selection showed significant enrichment for gene ontology (GO) terms relating to developmental processes and phosphorylation, which seems consistent with assumptions that differences in larval phase duration and migratory distances underlie speciation. Most SNPs under putative selection were found outside coding regions, lending support to emerging views that noncoding regions may be more functionally important than previously assumed. In total, the results demonstrate the necessity of interpreting genomic footprints of selection in the context of demographic parameters and life‐history features of the studied species.  相似文献   

20.
The study of hybrid inviability reveals cryptic divergence between the genetic interactions that maintain stable phenotypes in the pure species . We characterized the effects of natural variation on the penetrance of hybrid inviability phenotypes in crosses between Drosophila melanogaster and two species of the D. simulans subcomplex, D. simulans and D. sechellia. Using a panel of wild‐caught lines, we studied the levels of genetic variance present in D. simulans and D. sechellia affecting prezygotic and post‐zygotic isolation in hybridizations with D. melanogaster females. We observed extensive variability in the viability of hybrid individuals, dependent on the genotype of the parents, suggesting that intraspecific natural variation manifests directly in hybrid phenotypes. Furthermore, we found that genetic background significantly affects the penetrance of a well‐studied determinant of hybrid inviability: the interaction between Hmrmel–Lhrsim. Our results suggest that hybrid inviability – and reproductive isolation generally – can be modified by polymorphisms at multiple loci segregating within the parental species. Just as the penetrance of most mutant phenotypes can be modified by the genetic background within the pure species, the penetrance of hybrid inviability phenotypes is highly influenced by the parental genotypes.  相似文献   

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