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1.
Extant variation in temperate and boreal plant species has been influenced by both demographic histories associated with Pleistocene glacial cycles and adaptation to local climate. We used sequence capture to investigate the role of these neutral and adaptive processes in shaping diversity in black cottonwood (Populus trichocarpa). Nucleotide diversity and Tajima's D were lowest at replacement sites and highest at intergenic sites, while LD showed the opposite pattern. With samples grouped into three populations arrayed latitudinally, effective population size was highest in the north, followed by south and centre, and LD was highest in the south followed by the north and centre, suggesting a possible northern glacial refuge. FST outlier analysis revealed that promoter, 5′‐UTR and intronic sites were enriched for outliers compared with coding regions, while no outliers were found among intergenic sites. Codon usage bias was evident, and genes with synonymous outliers had 30% higher average expression compared with genes containing replacement outliers. These results suggest divergent selection related to regulation of gene expression is important to local adaptation in P. trichocarpa. Finally, within‐population selective sweeps were much more pronounced in the central population than in putative northern and southern refugia, which may reflect the different demographic histories of the populations and concomitant effects on signatures of genetic hitchhiking from standing variation. 相似文献
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Antibacterial activity of Turkish propolis and its qualitative and quantitative chemical composition 总被引:7,自引:0,他引:7
The antibacterial activity of propolis from different regions of Turkey was studied, accompanied by TLC and GC-MS analyses of its chemical composition and spectrophotometric quantification of the most important active principles. All six samples were active against the bacterial test strains used; however, samples 1 (Yozgat), 2 (Izmir) and 3 (Kayseri) were more active than samples 4 (Adana), 5 (Erzurum) and 6 (Artvin). By TLC comparison all samples were found to contain poplar taxonomic markers but in samples 4 (Adana), 5 (Erzurum) and 6 (Artvin), different substances were observed, which were not present in P. nigra L. bud exudate. The typical poplar samples 1 (Yozgat), 2 (Izmir) and 3 (Kayseri) displayed very similar phenolic and flavonoid content. Samples 4 (Adana), 5 (Erzurum) and 6 (Artvin) were characterized by low phenolic and very low flavonoid concentrations. Qualitative analysis by GC-MS revealed that sample 4 (Adana) contained diterpenic acids and high percent of cinnamyl cinnamate, sample 5 (Erzurum)-significant amounts of hydroxy fatty acids and triterpenic alcohoLs, and sample 6 (Artvin)-phenolic glycerides, characteristic for the bud exudate of Populus euphratica Oliv. The results confirm the importance of phenolics for propolis antibacterial activity, and the significance of P. nigra L. as a propolis source, which provides the hive with the best defense against microorganisms. 相似文献
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Zenon Lukaszewski Ryszard Siwecki Jadwiga Opydo Wlodzimierz Zembrzuski 《Trees - Structure and Function》1993,7(3):169-174
Summary The patterns of radial distribution of copper, lead, zinc and cadmium in two species of poplar, growing under polluted conditions near a copper smelter, were investigated. Populus marilandica is very resistant to such pollution, but P. balsamifera is sensitive. Soils were examined for concentrations of these metals, and only a surface layer of soil was polluted with copper and lead. P. balsamifera absorbed much more cadmium than P. marilandica under the same conditions. P. marilandica shows a pattern of copper radial distribution with significantly increased concentration of the meral in the layers in the middle of the trunk compared to P. balsamifera. Zinc and cadmium have a pattern with increased metal concentration from the bark towards the pith of the tree. In the case of copper and lead the pattern indicates increased concentrations of these metals in the rings adjacent to the pith while the pattern in other parts of the tree remains unconfirmed due to poor precision. Poplar xylem seems to accumulate zinc and cadmium while the content of lead in xylem is much lower than in the adjacent soil.This paper is dedicated to the memory of Professor Stefan Bialobok, Institute of Dendrology, Polish Academy of Sciences in Kornik 相似文献
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Hans Hoenicka Denise Lehnhardt Ove Nilsson Dieter Hanelt Matthias Fladung 《Plant biotechnology journal》2014,12(8):1066-1074
In forest tree species, the reproductive phase is reached only after many years or even decades of juvenile growth. Different early flowering systems based on the genetic transfer of heat‐shock promoter driven flowering‐time genes have been proposed for poplar; however, no fertile flowers were reported until now. Here, we studied flower and pollen development in both HSP::AtFT and wild‐type male poplar in detail and developed an optimized heat treatment protocol to obtain fertile HSP::AtFT flowers. Anthers from HSP::AtFT poplar flowers containing fertile pollen grains showed arrested development in stage 12 instead of reaching phase 13 as do wild‐type flowers. Pollen grains could be isolated under the binocular microscope and were used for intra‐ and interspecific crossings with wild‐type poplar. F1‐seedlings segregating the HSP::AtFT gene construct according to Mendelian laws were obtained. A comparison between intra‐ and interspecific crossings revealed that genetic transformation had no detrimental effects on F1‐seedlings. However, interspecific crossings, a broadly accepted breeding method, produced 47% seedlings with an aberrant phenotype. The early flowering system presented in this study opens new possibilities for accelerating breeding of poplar and other forest tree species. Fast breeding and the selection of transgene‐free plants, once the breeding process is concluded, can represent an attractive alternative even under very restrictive regulations. 相似文献
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R. Holderegger S. Angelone S. Brodbeck D. Csencsics F. Gugerli S. E. Hoebee R. Finkeldey 《Trees - Structure and Function》2005,19(6):743-748
European Black Poplar (Populus nigra) is considered a rare and endangered tree species because of severe reduction of its natural riverine habitat and potential
hybridisation with the related non-indigenous taxa P. deltoides and P. x canadensis. As it is difficult to distinguish these taxa solely based on their morphology, we applied a PCR-based assay with an easy-to-use
and robust molecular marker set (cpDNA trnL-trnF/RsaI RFLP, nDNA win3 and nDNA POPX/MspI RFLP) in order to identify pure P. nigra. Different plant tissues could be used for fast and standardised DNA extraction. The application of the three marker types
was tested on a number of different Populus taxa, and they were also used for the verification of pure P. nigra in a sample of 304 putative P. nigra individuals from Switzerland. Cross-checking of the DNA data with those using a traditional allozyme approach resulted in
complete agreement. The availability of molecular identification methods is an important prerequisite for the conservation
of European Black Poplar, because pure, non-introgressed plant material can then be used in restoration projects of European
floodplains. 相似文献