| 词条 | Ulothrix |
| 释义 |
| taxon = Ulothrix | authority = Kützing | subdivision_ranks = Species | subdivision =
| synonyms =
}}Ulothrix is a genus of green algae in the family Ulotrichaceae.[1] Ulothrix is a genus of filamentous green algae, generally found in fresh and marine water. Its cells are normally as broad as they are long, and they thrive in the low temperatures of spring and winter. They become attached to surfaces by a modified holdfast cell. Reproduction is normally vegetative. They are Eukaryotic and unicellular. They are one of the 5 classes of microorganisms. The genus includes:- Ulothrix aequalis Kützing;[2]Ulothrix moniliformis Kützing[2]Ulothrix flacca (Dillwyn) Thuret in Le Jolis[3]Ulothrix implexa (Kützing)Kützing Ulothrix speciosa (Carmichael ex Harvey in Hooker) Kützing[3]Ulothrix tenerrima Kützing[2]Ulothrix tenuissima Kützing[2]Ulothrix zonata (Weber et Mohr) Kützing[2]StructureThe plant body consists of unbranched, uniseriate filaments. The cells of the filaments are arranged end to end. They are barrel-shaped or cylindrical in shape[2] The apical cell is somewhat rounded at its terminal end whereas the basal cell is elongated. It is also called the basal holdfast, which attaches the filament to the substratum.The cell wall is composed of propectin and cellulose and it lacks mucilage. Each cell has a single girdle-like and parietal chloroplast and two to many pyrenoids are present in each chloroplast ReproductionReproduction in Ulothrix takes place by means of vegetative, asexual and sexual methods. Vegetative reproductionThe common vegetative methods of reproduction are fragmentation and akinete formation. FragmentationVegetative cells of Ulothrix break into small pieces accidentally. Each fragment develops into a new filament. Akinete formationSome of the vegetative cells of Ulothrix are converted into thick walled akinetes. Food reserves are accumulated within the akinetes. When the conditions are favourable each akinete develops into a new plant. References1. ^See the NCBI [https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=43940 webpage on Ulothrix]. Data extracted from the {{cite web | url=ftp://ftp.ncbi.nih.gov/pub/taxonomy/ | title=NCBI taxonomy resources | publisher=National Center for Biotechnology Information | accessdate=2007-03-19}} 2. ^1 2 3 4 5 Guiry, M.D., John, D.M., Rindi, F and McCarthy, T.K. (ed.) 2007. New Survey of Clare Island Volume: The Freshwater and Terrestrial Algae Royal Irish Academy. {{ISBN|978-1-904890-31-7}} 3. ^1 Burrows, E.M. 1991. Seaweeds of the British Isles Volume 2 Chlorophyta. Natural History Museum, London {{ISBN|0-565-00981-8}} External links{{Taxonbar|from=Q226127}}{{Ulvophyceaye-stub}} 3 : Ulotrichaceae|Ulvophyceae genera|Taxa named by Friedrich Traugott Kützing |
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