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1.
 The polyploid Salix albaSalix fragilis hybrid complex is rather difficult to study when using only morphological characters. Most of the characters have a low diagnostic value for unambiguously identifying the hybrids, introgression patterns and population structures. Morphology and molecular variation determined with random amplified polymorphic DNAs (RAPDs) were investigated in a set of staminate and pistillate willows from Belgium. A thorough screening of possible RAPD markers was done to select homologous amplification products. The selected amplified products proved to be useful in a principal coordinate analysis for the identification of individuals from a morphological continuum comprising presumed pure species and introgressants. The RAPD based identity of the individuals or clones was checked against those based on morphological characters. A correspondence analysis indicated that all pubescence related characters were associated but separated from the size related characters. The RAPDs also revealed that the S. fragilis genotypes mainly consisted of staminate individuals whereas most of the pistillate trees belonged to the S. alba genotype cluster. It was suggested that both species have kept their gene pools well separated and that morphologically intermediate plants are not necessarily genetically intermediate. Received August 31, 1999 Accepted December 12, 2000  相似文献   

2.
Question: How does willow‐characterised tundra vegetation of western Eurasia vary, and what are the main vegetation types? What are the ecological gradients and climatic regimes underlying vegetation differentiation? Location: The dataset was collected across a wide spectrum of tundra habitats at 12 sites in subarctic and arctic areas spanning from NW Fennoscandia to West Siberia. Methods: The dataset, including 758 vegetation sample plots (relevés), was analysed using a TWINSPAN classification and NMDS ordination that also included analyses of vegetation‐environment correlations. Results: Based on the TWINSPAN classification, eight vegetation types characterised by willow (cover of upright willows >10%) were discerned: (1) Salix glaucaCarex aquatilis type, (2) AulacomniumTomentypnum type, (3) SalixBetulaHylocomium type, (4) Salix lanataBrachythecium mildeanum type, (5) SalixPachypleurum type, (6) S. lanataMyosotis nemorosa type, (7) Salix‐Trollius‐Geranium type and (8) SalixComarum palustreFilipendula ulmaria type. Willow‐characterised vegetation types were compositionally differentiated from other tundra vegetation and were confined to relatively moist valley and sloping tundra sites, from mire to mineral soils. These vegetation types were encountered across a broad latitudinal zone in which July mean temperature ranged from 6 to 10°C. Conclusions: Willow‐characterised tundra vegetation forms a broad category of ecologically and geographically differentiated vegetation types that are linked to dwarf shrub tundra, shrub tundra or mire. Because of complex ecological gradients underlying compositional differentiation, predicting the responses of willow‐characterised tundra vegetation to a warming climate may be complicated.  相似文献   

3.
Salix hukaoana is an endangered riparian tree that is found and known only in several isolated sites in eastern Japan, and that has been suffering from the loss and fragmentation of its habitat. To investigate the genetic variation and structures of this willow in these sites, eight polymorphic microsatellites with three to eight alleles were characterized. Cross‐species amplification was successful for many of the loci using the congeners Salix sachalinensis and Chosenia arbutifolia. This set of microsatellites will be useful for the study of the spatial genetic structures of S. hukaoana and other coexisting willows suffering from habitat fragmentation in riparian forests.  相似文献   

4.
Microsatellite markers are suitable tools for studying dispersal pattern among local populations. I report on the characterization of seven polymorphic microsatellite loci in the scarce heath butterfly (Coenonympha hero), from one unenriched and one enriched genomic library. Number of alleles ranged from two to 20 when 108 individuals from seven populations were screened. HO ranged from 0.140 to 0.889. Primers were also tested on three other butterfly species. Amplification was successful for all loci in Erebia triaria, while only one gave products in Maculinea alcon and Maculinea rebeli. To my knowledge, these are the first microsatellite markers published in the Nymphalidae subfamily Satyrinae.  相似文献   

5.
A North Atlantic right whale (Eubalaena glacialis) genomic library was developed and screened with a (GATA)8 probe to identify tetranucleotide microsatellite loci. Sixteen characterized loci were polymorphic in North Atlantic and/or South Atlantic (Eubalaena australis) right whales, 12 being polymorphic in E. glacialis, and 15 in E. australis. Fourteen of these were combined with 21 other previously identified loci for a suite of 35 loci which can be used to increase resolution of genetic analyses of these species. Multiplex reactions were developed for genotyping samples at these loci, providing a method that is rapid, reliable and cost‐effective.  相似文献   

6.
The influence of photoperiod on the metabolism of GA20 in Salix pentandra was studied by feeding [3H]-GA20 to seedlings which had been grown previously under long day (LD) or short day (SD) conditions. After 48 h in LD or SD, metabolites were separated on sequential, silica gel partition columns and reversed-phase C18 HPLC. The principal metabolite co-chromatographed with [3H]-GA1 and this conversion was confirmed by feeding [2H]-GA20, which was converted to [2H]-GA1 as identified by gas chromatography-selected ion monitoring. Chromatographic evidence also indicated the minor conversion of [3H]-GA20 to [3H]-GA8 (via [3H]-GA1) and trace conversion to [3H]-GA29 (GAs A1.8,20.29 are native in Salix). Ethyl acetate-insoluble [3H] metabolites were formed and could be cleaved by cellulase to release putative [3H]-GA20 and [3H]-GA1 suggesting the conversion to glucosyl conjugates of these GAs. Metabolism of [3H]-GA20 was slightly more rapid in plants previously grown under LD than SD, an effect which reflected the generally increased shoot growth under LD. However, altering the photoperiod after [3H]-GA20 addition had only a slight effect on the metabolism of [3H]-GA20 in Salix seedlings. This indicates that the conversion of GA20 to GA1 is not a controlling step in the photoperiodic regulation of growth cessation in Salix.  相似文献   

7.
Salix reinii Franch. et Savat., a crawl shrub, is one of the most dominant pioneer trees on the southeastern slope of Mt. Fuji, on which an early stage of the volcanic desert succession has been underway since the last eruption in 1707. To investigate the population genetic structure within and among patches of S. reinii, seven polymorphic microsatellite markers were developed by an enrichment procedure. The multiple banding patterns amplified by developed microsatellite markers showed the polyploidy in S. reinii growing on the southeastern slope of Mt. Fuji.  相似文献   

8.
The effect of photoperiod on metabolism of 16,17-[3H2]GA19, and 1.2-[3H2]GA1 applied to intact seedlings of Salix pentandra, was investigated. No difference was found in conversion of 16,17-[3H2]GA19 to 16,17-[3H2]GA20, and 16,17-[3H2]GA1, or in metabolism of 1,2-[3H2]GA1 to [3H]GA8 between plants grown in continuous light and plants exposed for 14 days to a 12-h photoperiod. Also, leaf discs from plants grown in long or short days, converted 16,17-[3H2]GA19 both in light and darkness. These data on metabolism of 16,17-[3H2]GA19, contrast with previous results, which have indicated a photoperiodic control of the metabolism of GA19 to GA20 in S. pentandra. Presence of these applied labelled GAs and their metabolites in different parts of seedlings was recorded, after application to intact seedlings as well as to isolated plant parts. When 16,17-[3H2]GA19 was applied through the roots of intact plants, the relative amounts of 16,17-[3H2]GA1 present in leaves and shoot apices were higher than in roots and stems. In corresponding experiments with 1,2-[3H2]GA1, relatively higher amounts of [3H2]GA8 were found in roots and stems than in leaves and shoot apices. Twenty-four hours after application of 16,17-[3H2]GA19 to isolated plant parts, 16,17-[3H2]GA20 and 16,17-[3H2]GA1 were found in leaves and roots, but not in internodes. Incubation of isolated plant parts with 1,2-[3H2]GA1 for 24 h resulted in presence of [3H]GA8 in all parts. The results mentioned above were obtained by monitoring metabolites by HPLC with on-line radio counting. The conversions of 17-[2H2]GA19 to 17-[2H2]GA20 and 17-[2H2]GA1 in shoot apices and whole seedlings, and of 17-[2H2]GA8 in whole seedlings, were confirmed by GC-MS.  相似文献   

9.
Forty‐six microsatellites were isolated from an enriched library of Salix burjatica and tested on 20 individuals (of nine species/hybrids) from the National Willows Collection (IACR‐Long Ashton Research Station, UK). Twenty‐nine were monomorphic, gave multilocus or unscorable patterns, or were duplicates. The remaining 17 microsatellites gave 2–22 alleles/locus. Three microsatellites successfully cross‐amplified in 31 additional Salix species. A further six were tested on panels comprising 6–25 individuals from the 31 species. Cross‐amplification was successful in all cases. These results suggest that the microsatellites isolated here should prove useful for population studies in a wide range of Salix species.  相似文献   

10.
Fourteen primer pairs were designed from 47 sequences containing microsatellites isolated from a genomic library enriched for (GACA)4 in Stegastes partitus. Seven of these were shown to be polymorphic and provided clean amplification products. These seven loci were further characterized using 38 individuals, yielding a range in number of alleles from 5 to 31 and observed and expected heterozygosity values ranging from 0.45–0.89 and 0.66–0.96 respectively. Six of seven loci conformed to Hardy-Weinberg equilibrium. Successful amplification was also achieved in other Pomacentridae.  相似文献   

11.
Seven microsatellite loci were isolated and characterized from the red‐capped robin Petroica goodenovii, using nonradioactive polymerase chain reaction (PCR)‐based techniques to screen an enriched genomic library. Five loci showed no evidence of null alleles and were variable [mean heterozygosity (HE) = 0.440, mean number of alleles = 8]. Cross‐amplification using primers for microsatellites in Phylloscopus occipitalis and Emberiza schoeniclus yielded another two polymorphic loci. The combined set of five red‐capped robin and two cross‐amplified loci are suitable for paternity assignment (exclusion probability for seven unlinked loci = 0.9760).  相似文献   

12.
Thirteen microsatellite loci were developed from an (AG)‐enriched library using Telopea speciosissima, a widespread species of dry‐sclerophyll forest in New South Wales (NSW, Australia). Genotyping of 30 seeds from one population of T. speciosissima and 15 seeds from one population of the related Telopea aspera (restricted to the Gibraltar Range in northern NSW) was successfully performed. The loci were also tested across seven other related species. The microsatellites will be used to compare population dynamics across a range of taxa representing different distribution patterns.  相似文献   

13.
We isolated and characterized microsatellite markers for the red flour beetle Tribolium castaneum, an important model species for studies in various areas of evolutionary biology and ecology. A microsatellite‐enriched genomic library was constructed and screened with single stranded oligonucleotide probes [(CCT)17, (AAT)17 and (CAG)17]. Forty‐five primer pairs were designed of which 19 pairs produced successful amplification. Polymorphism screening involved beetles from five beetle strains and revealed 15 polymorphic and four monomorphic markers. The development of polymorphic microsatellite markers will facilitate future ecological and genetic studies involving T. castaneum beetles.  相似文献   

14.
Microsatellite loci were isolated in Haliotis fulgens using a (CT)n enriched‐genomic library. From 33 sequenced clones, 21 microsatellites regions were identified, 15 with the expected (CT)n. Eight microsatellite loci were amplified, six of which were polymorphic with a range of three to 20 alleles, and five cross‐amplified in two other species (Haliotis rufescens and Haliotis corrugata). These microsatellites will be useful as population genetic markers in the three species.  相似文献   

15.
 Dinucleotide microsatellites were isolated from Pinus radiata using both a standard genomic library and libraries enriched for microsatellites. Locus-specific primers were designed to amplify 43 unique microsatellites. Thirty two of these loci had interpretable PCR patterns, 11 of which were polymorphic in a screen of 19 P. radiata individuals; all 11 polymorphic loci contained at least 17 repeats in the sequenced plasmid. Six of the eleven primer pairs amplified multiple fragments per individual (3–8), suggesting that these loci were present in multiple copies in the genome. Genotyping a 48-tree P. radiata production population with seven of the most polymorphic microsatellites revealed an average of 17 bands per locus (the multi-copy microsatellites were treated as one locus). When tested on known pedigrees, both single and multi-copy microsatellites exhibited co-dominant inheritance and Mendelian segregation. Two loci had null alleles and one locus had a high frequency of non-parental alleles, suggesting a high mutation rate. Eight of these microsatellites, including five multi-copy loci, were placed on a partially constructed P. radiata genetic map. Four of the five multi-copy microsatellites had two or more sets of alleles that mapped to the same locus, and the fifth mapped to two unlinked loci. All seven tested primer pairs amplified PCR products from other species of hard pine, three amplified products from soft-pine species, and one amplified bands in other conifers. Received: 10 November 1997 / Accepted: 5 January 1998  相似文献   

16.
Screening for fungi capable of removing benzo[a]pyrene in culture   总被引:3,自引:0,他引:3  
Some 17 strains of filamentous fungi, encompassing 13 different species, were tested for their ability to decolorize the polymeric dye R-478. Decolorization was observed with both living and dead mycelia of the three Aspergillus species tested, indicating bioadsorption, not biodegradation. With mycelia of other strains tested, the most decolorization was obtained with Marasmiellus troyanus, Pleurotus sapidus, and Pleurotus ostreatus; with extracellular filtrates, the most decolorization was observed with Laetiporus sulphureus. Parallel experiments incubating benzo[a]pyrene (B[a]P) with mycelia and filtrates showed that six of the species removed over 40% of B[a]P in comparison with HgCl2-killed controls. The highest B[a]P removal by mycelia was shown by M. troyanus (95.0%); the highest level by extracellular filtrates was shown by Hericium erinaceous (44.8%). With the exception of A. ochraceous, no products of B[a]P metabolism were detected for any of the species tested. For most species, the disappearance of B[a]P was correlated with the ability to decolorize poly R-478 ( r = 0.78 for mycelia; r = 0.74 for culture fluids). M. troyanus gave rise to more disappearance than decolorization. The removal of B[a]P by M. troyanus and Phanerochaete chrysosporium was compared over 30 days: M. troyanus gave significantly better removal in a biphasic pattern. Received: 8 July 1996 / Received revision: 11 November 1996 / Accepted: 29 November 1996  相似文献   

17.
The experiment assessed the variability of in seven clones of willow plants of high biomass production (Salix smithiana S-218, Salix smithiana S-150, Salix viminalis S-519, Salix alba S-464, Salix ’Pyramidalis’ S-141, Salix dasyclados S-406, Salix rubens S-391). They were planted in a pots for three vegetation periods in three soils differing in the total content of risk elements. Comparing the calculated relative decrease of total metal contents in soils, the phytoextraction potential of willows was obtained for cadmium (Cd) and zinc (Zn), moderately contaminated Cambisol and uncontaminated Chernozem, where aboveground biomass removed about 30% Cd and 5% Zn of the total element content, respectively. The clones showed variability in removing Cd and Zn, depending on soil type and contamination level: S. smithiana (S-150) and S. rubens (S-391) demonstrated the highest phytoextraction effect for Cd and Zn. For lead (Pb) and arsenic (As), the ability to accumulate the aboveground biomass of willows was found to be negligible in both soils. The results confirmed that willow plants show promising results for several elements, mainly for mobile ones like cadmium and zinc in moderate levels of contamination. The differences in accumulation among the clones seemed to be affected more by the properties of clones, not by the soil element concentrations or soil properties. However, confirmation and verification of the results in field conditions as well as more detailed investigation of the mechanisms of cadmium uptake in rhizosphere of willow plants will be determined by further research.  相似文献   

18.
《Mycoscience》2020,61(4):151-154
The relative abundance of ectomycorrhizal (ECM) roots in pure and mixed stand compositions of Dryas octopetala, Salix repens and Arctostaphylos uva-ursi grown in Scottish coastal arctic/alpine relict habitat was described through ECM morphotyping and comparisons of fungal internal transcribed spacer sequences. Neither specific ECM morphotypes nor the morphotype communities were found in association with any stand compositions. The proportions of the ECM roots on S. repens, however, were significantly less in pure stand and were further decreased in mixed with A. uva-ursi. Possible factors contributing the reduction, including the effects by other host species grown in proximity, are discussed.  相似文献   

19.
Abstract: We have recently shown that brain slices are capable of metabolizing arachidonic acid by the epoxy-genase pathway. The purpose of this study was to begin to determine the ability of individual brain cell types to form epoxygenase metabolites. We have examined the astrocyte epoxygenase pathway and have also confirmed metabolism by the cyclooxygenase and lipoxygenase enzyme systems. Cultured rat hippocampal astrocyte homogenate, when incubated with radiolabeled [3H]-arachidonic acid, formed products that eluted in four major groups designated as R17–30, R42–50, R51–82, and R83–90 based on their retention times in reverse-phase HPLC. These fractions were further segregated into as many as 13 peaks by normal-phase HPLC and a second reverse-phase HPLC system. The principal components in each peak were structurally characterized by gas chromatography/electron impact-mass spectrometry. Based on HPLC retention times and gas chromatography/electron impactmass spectrometry analysis, the more polar fractions (R17–30) contained prostaglandin D2 as the major cyclooxygenase product. Minor products included 6-keto prostaglandin F, prostaglandin E2, prostaglandin F, and thromboxane B2. Fractions R42–50, R51–82. and R83–90 contained epoxygenase and lipoxygenase-like products. The major metabolite in fractions R83–90 was 5, 6-epoxyeicosatrienoic acid (EET). Fractions R51–82 contained 14, 15-and 8, 9-EETs, 12-and 5-hydroxyeicosatetraenoic acids, and 8, 9-and 5, 6-dihydroxyeicosatrienoic acids (DHETs). In fractions R42–50, 14, 15-DHET was the major product. When radiolabeled [3H]14, 15-EET was incubated with astrocyte homogenate, it was rapidly metabolized to [3H]14, 15-DHET. The metabolism was inhibited by submicromolar concentration of 4-phenylchalcone oxide, a potent inhibitor of epoxide hydrolase activity. Formation of other polar metabolites such as triols or epoxyalcohols from 14, 15-DHET was not observed. In conclusion, astro-cytes readily metabolize arachidonic acid to 14, 15-EET, 5, 6-EET, and their vicinal-diols. Previous studies suggest these products may affect neuronal function and cerebral blood flow.  相似文献   

20.
A cell-free system prepared from developing seed of runner bean (Phaseolus coccineus L.) converted [14C]gibberellin A12-aldehyde to several products. Thirteen of these were identified by capillary gas chromatography-mass spectrometry as gibberellin A1 (GA1), GA4, GA5, GA6, GA15, GA17, GA19, GA20, GA24, GA37, GA38, GA44 and GA53-aldehyde, all giving mass spectra with 14C-isotope peaks. GA8 and GA28 were also identified but contained no 14C. All the [14C]GA12-aldehyde metabolites, except GA15, GA24 and GA53-aldehyde, are known endogenous GAs of P. coccineus.Abbreviations GAn gibberellin An - GC-MS combined gas chromatography-mass spectrometry - HPLC highperformance liquid chromatography - MVA mevalonic acid - S-2 2000-g supernatant  相似文献   

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