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Glacial history of high alpine Ranunculus glacialis (Ranunculaceae) in the European Alps in a comparative phylogeographical context 总被引:1,自引:0,他引:1
PETER SCHÖNSWETTER REAS TRIBSCH IVANA STEHLIK HARALD NIKLFELD 《Biological journal of the Linnean Society. Linnean Society of London》2004,81(2):183-195
There is considerable controversy concerning the fate of Alpine plants during Pleistocene glaciations. While some studies have found evidence for nunatak survival, others have explained the present genetic patterns by survival only in peripheral refugia. We investigated 75 populations of high alpine Ranunculus glacialis from its entire Alpine distribution. Phylogeographical analyses of AFLP data revealed four groups of populations. Two of them, located in the western Alps, were genetically isolated from each other and from the eastern groups, whereas the two eastern Alpine groups were genetically more similar to each other. This suggests longer isolation and/or lower levels of gene flow in the two western groups. As all groups are close to, or overlap with, presumed glacial refugia, invoking glacial survival on nunataks is unnecessary to explain the present genetic pattern. Similar to the phylogeographical patterns of R. glacialis , the previously investigated alpine Phyteuma globulariifolium and Androsace alpina , which are also confined to siliceous bedrock, showed strong geographical affinities to peripheral refugial areas and there were large-scale congruencies in the location of these refugia for all three species. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 81 , 183–195. 相似文献
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CONCETTA CORSARO MARINA SCALIA ANNA RITA BLANCO IVANA AIELLO GIOVANNI SICHEL 《Pigment cell & melanoma research》1995,8(5):279-282
The susceptibility to lipoperoxidation in liver of albino and pigmented Xenopus laevis Daudin, has been studied. Albino Xenopus liver was richer in polyunsaturated fatty acids (PUFAs) than the pigmented one; moreover, it was also richer in mitochondrial superoxide dismutase (MnSOD) and in reduced glutathione (GSH). The thiobarbituric acid-reactive substances (TBARS) values were more abundant in the albino tissue compared to the pigmented tissue both during spontaneous and Fe++ induced lipoperoxidation. Therefore, when isolated and purified melanin, in physiological quantities, was added to albino tissue, the TBARS values drastically decreased. Thus, melanin, in our experimental conditions, protects the albino tissue even more than SOD and GSH do. Melanin, in our opinion, acts as an antioxidant, because it is able to scavenge O2?. 相似文献
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TYKVA RICHARD; MACHACKOVA IVANA; KREKULE JAN; JISL RUDOLF 《Journal of experimental botany》1992,43(8):1083-1087
A novel topographic method is described for the fully automatedquantitative resolution of activity of two simultaneously appliedbeta tracers in plant tissues. The advantages of this methodusing specially developed silicon detectors are demonstratedin studying the effect of direct current on the uptake and distributionof Ca2+ and P1 ions in leaves and stems of Chenopodium rubrum.This treatment has recently been shown to inhibit flower inductionin this plant. Key words: Radiotracer multi-labelling, computer-controlled resolution, quantitative topographic evaluation 相似文献
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IVANA LAZZARETTO-COLOMBERA 《Zoologica scripta》1981,10(1):33-36
In the Tisbe reticulata group, T. aragoi possesses n =ll, whereas T. marmorata and T. reticulata display n=12 . In relation to other species of this genus these species are characterized by relatively small dimensions of bivalents in oocytes. The discrepancy between karyological and morphological characters is discussed. 相似文献