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Heavily lichenized Physolinum monile (De Wildem.) Printz from damp limestone walls in a dimly lit cave located in Missouri was studied from fresh collections and specimens fixed in situ, and from cultures. The narrow (7-13 μm wide thallus), profusely branched plant consisted of filaments of the alga P. monile ensheathed by clear fungal cells (5-8 in a single layer) that adhered tightly to each other and completely covered the algal cells. Cells of P. monile filaments were uninucleate, each containing a single massive chloroplast with numerous tightly packed thylakoids and lipid droplets and surrounded by a thin layer of cytoplasm. No plasmodesmata occurred in the cellulosic crosswalls between adjacent cells. The ensheathing fungal cells contained concentric bodies, produced haustoria that penetrated the algal cells, and developed hyphae (the tips of which formed clusters of conidia). Ensheathing fungal cells were well situated and constructed to concentrate light on the algal cells. Colonies of blue-green algae were firmly attached to the surface of the fungal cells. The association was slow growing but frequently produced and released aplanospores from the algal cells. Aplanospores were single (not attached to each other) with smooth walls or united in groups of two or more. Structures resembling lichen soredia, composed of aplanospore-like cells attached to one or more comdia-like cells, commonly occurred among the lichenized Physolinum filaments. The single chloroplast that occupies most of the cell's volume, the numerous, tightly packed thylakoids, and light focusing by ensheathing fungus cells may enable the organism to survive in a dimly lit environment. Because the filamentous alga reproduces only by aplanospores, we propose resurrection of the genus Physolinum. The lichenized Physolinum somewhat resembles the lichens Coenogonium moniliforme Tuck. and Cystocoleus Thwaites. 相似文献
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基于形态学和化学研究发现中国蜈蚣衣科地衣中的5个新记录种:美洲哑铃孢、红髓外蜈蚣叶、狭叶红髓黑蜈蚣叶、毛裂芽黑蜈蚣叶和变白蜈蚣衣。对每个种的分类学特征给予了描述和讨论,并提供形态特征图。所有研究的标本保存于中国科学院微生物研究所菌物标本馆。 相似文献
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Here, cyanobiont selectivity of epiphytic lichen species was examined in an old growth forest area in Finland. Samples of the eight lichen species were collected from the same aspen (Populus tremula) and adjacent aspens in the same stand. The cyanobionts of these samples were compared with free and symbiotic Nostoc obtained from other habitats and geographic regions. Our results, based on the phylogenetic analysis of a partial small subunit of the ribosomal DNA (16S rDNA) and the rbcLX gene complex did not show any correlation with the geographic origin of the samples at any spatial scale. Instead, there was a correlation between the cyanobionts and the alleged taxonomy of their mycobionts. The results indicate that the lichen species examined are highly selective towards their cyanobiont partners. Only Lobaria pulmonaria proved to be more flexible, being able to associate with a wide range of Nostoc. A same Nostoc strain was found to form associations with taxonomically unrelated lichens indicating that the cyanobiont-mycobiont associations as a whole were not highly specific in the examined species. 相似文献
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报道了猫耳衣属的2个亚洲新记录种——好望角猫耳衣(Leptogium capense)和拟糠猫耳衣(L.pseudofurfuraceum)。与其他国家和地区的文献报道相比,好望角猫耳衣在中国具有更高的海拔分布,拟糠猫耳衣具有较薄的地衣体。 相似文献
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We report the species composition of subaerial epixylic algae and cyanobacteria from a South-East Asian mountain rainforest
locality in Cibodas, West Java. Green algae (Trebouxiophyceae, Chlorophyceae, Trentepohliales) were dominant and Cyanobacteria were the second most frequent group. We specifically concentrated on the comparison of species composition of closed primary
forest and open antropogenic spaces. Trentepohliales and Cyanobacteria dominated in open spaces with higher light intensities, whereas closed forest localities were dominated by trebouxiophycean
coccal green algae. There was a significantly higher algal diversity in open spaces than in closed forest samples indicating
the limiting effect of light on subaerial algal communities of closed tropical forests. A number of isolated strains and morphotypes
probably represent undescribed taxa.
Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia. 相似文献
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Very old, undisturbed forest stands may be important for biodiversity through their content of microhabitats or for the long periods available for colonisation, or for both. The term Ecological Continuity (EC) has been used to ascribe value to old forest stands. The relative importance of microhabitat and time for colonisation are usually not kept apart when EC is used as a conservation criterium. EC is broadly applied but poorly defined. Use of EC may lead to underestimation of the importance of forest dynamics and dispersal, and to overestimation of the importance of local land use history. If bioindicators of long-term habitat persistence are to be used, species with low dispersal capacity should be chosen. However, many lichens and other fungi, bryophytes and insects cited as indicators of EC, seem to have a patch-tracking lifestyle. They are 'colonists' according to life history strategy classification, and rather seem to indicate specific microhabitats. Terrestrial molluscs, some vascular forest plants, and those bryophytes and lichenized fungi classified as 'perennial stayers' in life history strategy classification, might be used to indicate long-term habitat persistence in forests, but more research is needed to evaluate such indicators. 相似文献