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Periphyton on artificial substrata from three lakes of different trophic status at Hope Bay (Antarctica) 总被引:5,自引:0,他引:5
The nutrient characteristics of aquatic environments at Hope Bay (Antarctica) depend on different factors, penguin enrichment being one of the most important. In this study we surveyed three water bodies of different morphometry and trophic status: Esperanza Lake (oligotrophic), Boeckella Lake (meso-eutrophic), and Pingüi Pond (hypereutrophic). This research provides a preliminary characterization of the periphyton colonization on artificial substrata (glass slides) of these water bodies from the end of January to mid-March 2000. Qualitative and quantitative analyses of the algae, chlorophyll a, dry weight, ash-free dry weight, and physical and chemical variables of the lakes were assessed. The Autotrophic Index and the Lakatos system of classification were also applied. All three lakes differed clearly in all the variables considered. The periphyton from Esperanza Lake was first dominated by Bacillariophyceae and subsequently by the chrysophyce Phaeogloea mucosa. P. mucosa was the dominant species at Boeckella Lake and Chlamydomonas subcaudata was dominant at Pingüi Pond. Highest mean maximum density values were reached at Pingüi Pond, followed by Boeckella and Esperanza Lakes. Highest biomass figures were registered with increasing trophic status. According to the Lakatos index, the periphyton of Esperanza Lake was the least developed and it was mainly organic and heterotrophic; Boeckella Lake showed intermediate development in periphyton mass, which was autotrophic and mainly inorganic whereas Pingüi Pond showed the highest development in periphytic mass, and it was mainly autotrophic. 相似文献
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Periphyton flora of some lotic and lentic environments of Hope Bay (Antarctic Peninsula) 总被引:7,自引:6,他引:1
A taxonomic study was made of the periphytic algal flora of some freshwater environments at Hope Bay, Antarctic Peninsula (63°27S; 56°59W), during summer 1992–1993. Seven lakes and two pools that are characterized by different trophic levels were studied. The largest, Boeckella Lake, has an important outflow (Prasiola Stream) that was also analyzed. Ninety-seven algal taxa, including specific and infraspecific entities, are recorded. Thirty-one new records for the Antarctic continent are described and illustrated. The flora comprises 44.4% Cyanophyceae, 21.6% Bacillariophyceae, 18.5% Chlorophyceae, 9.3% Tribophyceae, 4.2% Chrysophyceae and 2% Zygophyceae. The epilithic flora of Hope Bay shows a high species richness. Phormidiumfragile and Lyngbya lagerheimii were the most abundant species among the Cyanophyceae. In the algal mats we also found Chrysophyceae (mainly Hydrurus foetidus and Chrysococcus rufescens) and the macroscopic chlorophycean Prasiola crispa. Tribonema australis sp. nov. (Tribonematales, Tribophyceae) is put forward as a new species. Hormidium fluitans (Gay) Heering is renamed Klebshormidium fluitans. 相似文献
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Brinker M Brosché M Vinocur B Abo-Ogiala A Fayyaz P Janz D Ottow EA Cullmann AD Saborowski J Kangasjärvi J Altman A Polle A 《Plant physiology》2010,154(4):1697-1709
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Cassart Benoît Angbonga Basia Albert Jonard Mathieu Ponette Quentin 《Plant and Soil》2021,460(1-2):313-331
Plant and Soil - In tropical rainforests, soil respiration accounts for the major part of ecosystem respiration, yet a deep understanding of the influence of forest type and species composition is... 相似文献
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Enhanced bud regeneration in aspen (Populus tremula L.) roots cultured in liquid media 总被引:3,自引:0,他引:3
The regeneration potential of excised aspen (Populus tremula L.) roots cultivated in liquid medium, as affected by plant growth regulators and by the position of the isolated root explant
on the main root, was investigated. The effect of various levels of benzyladenine (BA) and thidiazuron (TDZ) on bud regeneration
in root explants was studied. TDZ in the medium had a marked effect on bud development as compared with BA, inducing a tenfold
increase in the number of buds regenerated from various root explants. TDZ enhanced both root and root-borne shoot biomass
production but reduced further shoot development and elongation. The position of the isolated root sections on the main root
affected regeneration, the proximal sections further away from the root tip producing the highest number of buds per explant
in both BA and TDZ treatments. Buds regenerated in close proximity to the site of lateral roots in BA-treated roots, while
in TDZ-treated root sections, the buds formed all over the root regardless of the presence of lateral roots. The buds developed
from inner cortical and sub-epidermal cell layers, disrupting the epidermis and the inner layers. Root biomass production
and growth was greatly enhanced in well-aerated bioreactor culture in the presence of 4.5×10–2 μM TDZ. A high number of the root-borne shoots could be rooted and converted to plantlets. However, while shoots regenerated
in a medium with BA rooted well in a growth regulator-free medium, shoots formed in a medium with TDZ required auxin for rooting.
Roots cultured in the presence of ancymidol, a gibberellin biosynthesis inhibitor, regenerated non-hyperhydric bud clusters
and hyperhydric shoots. These were separated mechanically, subcultured to growth and rooting medium and transplanted ex vitro
resulting in phenotypically true-to-type plantlets. The potential of liquid cultures for aspen shoot biomass production from
roots is discussed.
Received: 24 January 2000 / Revision received: 6 March 2000 / Accepted: 7 March 2000 相似文献
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Cyanophyta of lakes and ponds of Hope Bay,Antarctic Peninsula 总被引:6,自引:6,他引:0
This paper presents the results of the floristic inventory of the freshwater Cyanophyceae found in plankton samples from nine lakes and ponds at Hope Bay (Antarctic Peninsula). Forty taxa were recorded, among which nine are new records for Antarctica. All the taxa are illustrated, and their distribution in Antarctica as well as the ecological characteristics of the sampling sites are given. The main morphological features and the geographic distribution are also given for the new records. 相似文献
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Gene expression and metabolite profiling of Populus euphratica growing in the Negev desert 总被引:4,自引:0,他引:4
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Brosché M Vinocur B Alatalo ER Lamminmäki A Teichmann T Ottow EA Djilianov D Afif D Bogeat-Triboulot MB Altman A Polle A Dreyer E Rudd S Paulin L Auvinen P Kangasjärvi J 《Genome biology》2005,6(12):R101-17