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41.
青霉素对蓝藻细胞的作用 总被引:1,自引:1,他引:0
1967年,Biggins首次报道通过溶菌酶处理获得了有生活力的篇藻(Phormidium luridum)原生质球。此后,虽然许多作者在这方面作了不少工作,但原生质球的再生和融合问题至今没有得到解决。再生和融合与分离制备方法密切相关,因此, 相似文献
42.
Using high magnification Nomarski interference microscopy a series of optical sections has been obtained through flagellated cells of several green algae in an attempt to establish the absolute orientation of their basal bodies. Using this technique we have confirmed that in Spermatozopsis similis basal bodies are displaced into the 1/7 o'clock position, whereas in gametes of Enteromorpha linza, and zoospores of Trebouxia erici basal bodies are displaced into the 11/5 o'clock position. In addition we report for the first time that in zoospores of Microthamnion kuetzingianum basal bodies are also displaced into the 11/5 o'clock position. Basal body absolute orientations can thus be determined by light microscopy and do not require serial section electron microscopy. The method should be useful for class-level recognition of unknown green algae at the light microscope level. 相似文献
43.
柴达木盆地荒漠土壤蓝藻群落的初步研究 总被引:6,自引:0,他引:6
本文分析了柴达木盆地东部和中部具有代表性地区的丘陵、戈壁和沙丘的蓝藻种类组成、生物量及主要的土壤化学成分;采用了模糊聚类、系统聚类及多元线性回归等方法分析藻类的群落及其与环境因子的关系。共鉴定出21种蓝藻,其中6种为国内首次报道。研究表明:土壤含磷量、总盐量及与粘性和湿度有关的土壤结构是决定柴达木盆地蓝藻群落组成的重要因素。 相似文献
44.
Theodore I. Grand 《Zoo biology》1992,11(1):3-15
This model of growth offers a quantitative definition for altricial and precocial newborns, makes muscular strength a benchmark for locomotor independence, and discriminates related genera as well as genera across major taxonomic divides. The model contrasts four theoretical conditions of the neonate (I, small brain, weak musculature; II, small brain, strong musculature; III, large brain, weak musculature; IV, large brain, strong musculature) with species from three orders of placental mammal. Each species exhibits a distinct mother-infant strategy from the altricial red panda cub (condition I) and the golden lion tamarin (condition III) to the precocial wildebeest calf (condition IV). The model proposes that early growth rates of brain and muscle correlate with nutrition, maternal effort during gestation and lactation, and parental care, whereas postnatal muscular growth correlates directly with adult body size and locomotor repertoire. An example of condition II (small brain, strong musculature) has not been found. This suggests that muscle does not grow in advance of the brain and that the brain acts as a pacemaker of growth. In order to increase our understanding of exotic species, noninvasive measures (body weight and length) and observations (opening of the eyes and ears, hair density, weaning, and the abilities to ther-moregulate and to move) should be supplemented with analysis of the differential tissue and organ growth. In both theoretical and practical ways analysis of deceased individuals contributes to the understanding of all species. 相似文献
45.
P. R. Warman 《Plant and Soil》1991,134(1):115-119
A field-size experiment was initiated in 1982 on an acid, low fertility Springhill silt loam to determine the effect of five
unfertilized green manure crops (alsike clover, sweet clover, single- and double-cut red clover, and buckwheat) on subsequent
oat production and soil fertility. The field was limed in 1982 and green manures were seeded (without fertilizer) in spring,
1983 in 1400 m2 strips randomly assigned within three treatment blocks. Plant tissue samples were taken from different locations in each
plot in the fall of 1983 and all crops were incorporated. In 1984 the field was separated into an upper and lower section
and each section received three rates of NPK fertilizer (0; 30-36-36; 60-72-72 kg ha-1) spread across the previous strips. Gary oats were seeded and at harvest were divided into grain and straw. The results indicated
significant effects of field sample location, green manure type and fertilizer level on oat yields. Buckwheat significantly
reduced oat production compared to the four clovers, while the highest fertilizer rate improved oat yields compared with the
other levels of fertilizers. Elemental analysis of the green manure crops and soil fertility was compared with data of the
same crops grown in more fertile, neutral soils. 相似文献
46.
W. A. Berzonsky R. L. Clements H. N. Lafever 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1991,81(5):629-634
One cultivar (GR876) and two advanced Ohio soft red winter wheat lines (OH413 and OH414), with Kavkaz in their pedigrees, were examined for the presence of the Kavkaz, 1RS/1BL rye/wheat chromosome translocation. Another advanced line (OH416), with Amigo in its pedigree, was examined for the presence of the Amigo, 1RS/1AL translocation. Only two satellited chromosomes were observed in most mitotic root-tip cells from GR876, OH413, and OH414, compared to four in most cells from OH416. Heteromorphic bivalents were observed in most PMCs from hybrids produced by crossing GR876, OH413, and OH414 as females to Chinese Spring. No heteromorphic bivalents were observed in PMCs from OH416 x Chinese Spring hybrids. When GR876 and the Ohio lines were hybridized with Chinese Spring dimonotelosomic-1B, telosomic trivalents, consisting of the short- and longarm telosomes paired with chromosome 1B, were only observed in PMCs from 43-chromosome hybrids involving OH416. The long-arm telosome paired with the translocation chromosome, while the short-arm telosome remained unpaired in all other 43-chromosome hybrids. Separation of gliadin proteins from GR876 and the Ohio lines by PAGE revealed that secalin bands for GR876, OH413, and OH414, migrated similarly to the secalins for Kavkaz. Bands for OH416, identified as possible secalins, migrated similarly to those for Amigo. Cultivar GR876 and advanced Ohio soft red winter wheat lines OH413 and OH414 carry the Kavkaz translocation, while OH416 carries the Amigo translocation.Communicated by K. Tsunewaki 相似文献
47.
Cecilia Zazueta José A. Holguín Jorge Ramírez 《Journal of bioenergetics and biomembranes》1991,23(6):889-902
We describe a calcium transport that is sensitive to ruthenium red in liposomes reconstituted with mitochondrial extracts. This system is able to build an internally negative membrane potential, which allows the electrogenic influx of Ca2+ and Sr2+. Proteins with molecular weights higher than 35 kDa were incorporated to the vesicles, and enhanced the accumulation of the cation in an energy-dependent fashion. 相似文献
48.
The nucleotide sequences of the plastid 16S rDNA of the multicellular red alga Antithamnion sp. and the 16S rDNA/23S rDNA intergenic spacers of the plastid DNAs of the unicellular red alga Cyanidium caldarium and of Antithamnion sp. were determined. Sequence comparisons support the idea of a polyphyletic origin of the red algal and the higher-plant chloroplasts. Both spacer regions include the unsplit tRNAIle (GAU) and tRNAAla (UGC) genes and so the plastids of both algae form a homogeneous group with those of chromophytic algae and Cyanophora paradoxa characterized by small-sized rDNA spacers in contrast to green algae and higher plants. Nevertheless, remarkable sequence differences within the rRNA and the tRNA genes give the plastids of Cyanidium caldarium a rather isolated position. 相似文献
49.
Ester Cecere Orestina D. Saracino Margherita Fanelli Antonella Petrocelli 《Journal of applied phycology》1992,4(4):323-327
A survey is reported of the drifting algal community in Mar Piccolo, a polluted basin subject to sewage outlets. The key role was played by a few key species, mainly floridean red algae. 相似文献
50.
Piero Pollesello Renato Toffanin Erminio Murano Roberto Rizzo Sergio Paoletti Bjarne J. Kvam 《Journal of applied phycology》1992,4(2):149-155
Lipid extracts of the red algaGracilaria longa were studied by1H- and13C-NMR spectroscopy. Peaks in the13C-NMR spectra attributable to sterols, chlorophylls and carotenoids allowed free and acylated cholesterol, chlorophylla and lutein to be identified as the most abundant components of these classes. A content of 0.5 ± 0.1 μmoles of total cholesterol/g
wet alga was estimated from the1H-NMR spectrum, which also allowed the determination of the phosphatidylcholine/total lipid molar ratio (9.5 ± 0.5%). The13C-NMR spectroscopic experiments provided information on the position of the double bonds on the fatty acid residues. A comparison
between NMR spectra of lipid extracts obtained for wet and dried alga showed that the alga undergoes both a dramatic peroxidation
and some glycolipid degradation during the drying process. 相似文献