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Two main possibilities regarding glacial survival of the mountain flora of the Alps during the Quaternary have been discussed: the tabula rasa and the nunatak hypotheses. Eritrichium nanum (L.) Gaudin (Boraginaceae) is a perennial cushion plant, occurring at high elevations of the Central Alps and having a preference for extreme habitats. It belongs to a group of high-alpine plants, for which in situ glacial survival on nunataks is ecologically possible. By investigating 20 populations of E. nanum of potential nunatak and peripheral refugial regions using amplified fragment length polymorphism, considerable genetic differences between populations from the Central Alps and populations from peripheral refugia were detected; hence, the latter probably did not serve as potential sources for the re-colonization of the Central Alps after glaciation. Genetic variation was hierarchically structured (AMOVA), and three genetically distinct regions could be identified in the Central Alps. Two of these, the Penninic and Rhaetic Alps, correspond to nunatak regions proposed in the biogeographic literature. Populations from the Lepontic Alps formed a third genetic group. Genetic correlation (Mantel statistics) was highest within populations, with a modest decline among populations within specific nunatak regions and a negative correlation outside the genetic influence of specific nunatak regions. In situ glacial survival in E. nanum could be a model for the Quaternary history of other alpine plants, especially those that also occur at high elevations and in similar habitats. 相似文献
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Open-top chambers were used to estimate the possible effects of global warming on δ13C of seven plant species grown in alpine meadow ecosystem. The δ13C values of plant species were lower after long-term growth in open-top chambers. In the course of experiment, temperature
significantly increased inside the chambers by 4°C. Plant species grown at a lower elevation above sea level had higher δ13C values as compared to those grown at a higher elevation. This was in accordance with the effect of open-top chamber on δ13C values in plants. Greater availability of CO2 and lower water vapor pressure at higher temperature inside the chambers, as indicated by an increase in discrimination against
13CO2, probably result in more negative δ13C values of plants because higher stomatal conductance increases availability of CO2 and causes greater discrimination against 13CO2. The plant species studied could be the indicator species for testing global warming by the change in carbon isotope ratios
at the two growth temperatures.
This text was submitted by the authors in English. 相似文献
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紫草科Boraginaceae青海齿缘草属(Eritrichjum)新种,互助齿缘草E.huzhuense. 相似文献
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Flower development, pollination and breeding system of the high alpine cushion plant, Eritrichium nanum (Boraginaceae), were investigated in nine populations from the European Alps at altitudes of 2700 m–3200 m. Peak flowering
period lasts longer than a month, from mid-June to the end of July. In contrast to statements in the literature that flowers
are protogynous and nutlets remain in their calyx until spring we found a distinct protandry and nutlets being dispersed before
mid-September. Various insects from 12 families, but mostly Diptera, frequently visited E. nanum flowers, with flies from the families Anthomyiidae and Muscidae being the predominant visitors. Under optimal conditions
(max. solar radiation, min. wind force), visitation rates of 200 simultaneously observed flowers reached 32.5–46.7 insects
per hour, i.e. 0.16–0.24 insects per flower per hour. However, the commonly observed Anthomyiidae and Muscidae clearly preferred
the white-yellowish flowers of Saxifraga exarata and Saxifraga bryoides which are abundant at E. nanum sites and which are certainly also pollinated by species of these two fly families. The flowers of these Saxifraga species offer plenty of nectar and may compete for pollinators with E. nanum, when they are flowering in its proximity. However, various other insects like Pontia callidice and Psodos sp. (Lepidoptera) as well as Andrena sp. (Hymenoptera) and especially Eristalis tenax and closely related hoverflies showed a higher degree of flower constancy to E. nanum, often flying from a blue Eritrichium cushion to the next and hence causing outcrossing. The five fornices of E. nanum flowers which obstruct the tube containing stamens and nectar, are a feature which differs distinctly from the syndrome of
fly-pollinated flowers with easily accessible nectar. Consequently pollination by flies in E. nanum seems to be caused mainly by the unfavorable ecological conditions at high altitudes, where flies are the most frequent insects.
Bagging experiments showed that outcrossing and geitonogamy are the prevailing pollination modes, and autogamy, although possible,
plays only a minor role.
Received February 13, 2001 Accepted November 23, 2001 相似文献
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Bulgakov VP Veselova MV Tchernoded GK Kiselev KV Fedoreyev SA Zhuravlev YN 《Planta》2005,221(4):471-478
Rabdosiin and related caffeic acid metabolites have been proposed as active pharmacological agents demonstrating potent anti-HIV and antiallergic activities. We transformed Eritrichium sericeum and Lithospermum erythrorhizon seedlings by the rolC gene, which has been recently described as an activator of plant secondary metabolism. Surprisingly, the rolC-transformed cell cultures of both plants yielded two- to threefold less levels of rabdosiin and rosmarinic acid (RA) than respective control cultures. This result establishes an interesting precedent when the secondary metabolites are differently regulated by a single gene. We show that the rolC gene affects production of rabdosiin and RA irrespective of the methyl jasmonate (MeJA)-mediated and the Ca2+-dependent NADPH oxidase pathways. Cantharidin, an inhibitor of serine/threonine phosphatases, partly diminishes the rolC-gene inhibitory effect that indicates involvement of the rolC-gene-mediated signal in plant regulatory controls, mediated by protein phosphatases. We also show that the control MeJA-stimulated E. sericeum root culture produces (–)-rabdosiin up to 3.41% dry weight, representing the highest level of this substance for plant cell cultures reported so far. 相似文献
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本文列出中国地星科真菌3属18种主要特征检索表,其中有中国新记录属毛地星属Trichaster Czern.;中国新记录种4个:黑头毛地星Trichaster melanocephalus Czern.,伯克利地星Geastrum berkeleyi Massee,摩根地星G. morganii Lloyd和矮小地星 G. nanum Pers.。除新记录属、种的形态描述外,还附有宏观特征图和担孢子的扫描电镜照片。 相似文献
8.
植物叶片对环境变化十分敏感,能反映植物适应环境所形成的生存策略。为揭示高寒植物叶片性状对海拔高度变化的响应,对位于青藏高原东北部的冷龙岭3400—4200 m之间5个不同海拔高度的矮火绒草(Leontopodium nanum)叶片进行取样,采用常规石蜡制片技术和显微观察方法测定叶片外部形态、表皮气孔特征和解剖结构,探讨其叶片性状随海拔的变化,结果表明:(1)随海拔高度升高,叶面积呈减小的趋势,而比叶重和叶干物质含量增加;(2)叶片下表皮气孔密度随海拔升高呈先增加后下降的趋势,且气孔密度、气孔器面积、长度、宽度和潜在气孔导度指数等气孔特征之间存在显著相关性;(3)叶厚、栅栏组织和海绵组织厚度随海拔升高呈显著增厚的趋势;(4)叶片解剖结构可塑性和相关性分析显示,上、下角质层厚度的可塑性指数最大,而部分解剖结构指标间存在极显著的相关性。研究表明,矮火绒草为适应沿海拔上升温度降低的环境,主要采取叶片变小、变厚的对策,使植物趋于保温、保水和抗机械损伤的方向发展,并将资源最大化地投入到自身生长发育中。 相似文献
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《Bioscience, biotechnology, and biochemistry》2013,77(5):1286-1293
During an investigation of plant cell cultures that might be useful in the treatment of renal disorders, we established a vigorously-growing E-4 callus culture of Eritrichium sericeum that produced large amounts of caffeic acid metabolites, (?)-rabdosiin (1.8% dry wt) and rosmarinic acid (4.6% dry wt). Elicitation of the calli by methyl jasmonate induced a 38% increase in total polyphenol production. The most efficient method of eliciting (?)-rabdosiin biosynthesis was through the treatment of E-4 calli with cuprum glycerate, which induced an increase in (?)-rabdosiin production of as much as 4.1% dry wt. Oral administration of E-4 callus biomass (100 mg/kg/d for 30 d) to rats with induced Masugi-nephritis caused an increase in diuresis and lowered creatinine excretion and proteinuria levels as compared with Masugi-nephritis untreated rats. While all of the Masugi-nephritis untreated rats began to suffer, near a quarter of the E-4 treated rats remained in good health. This result indicates that the E-4 culture has the potential to alleviate the symptoms associated with nephritis. 相似文献
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