A New Method For Axenic Mass Cultivation of Paramecium Tetraurelia*

SYNOPSIS A method is described for the axenic mass cultivation of Paramecium tetraurelia strains 51s and 299s. the ciliate is grown in an enriched axenic medium developed by Soldo, Godoy & van Wagtendonk. Under continuous shaking on a rotary shaker, cultures were grown in one-liter Erlenmeyer flasks with 330 ml medium yield cell densities of 32,000 cell/ml and 20,000 cells/ml for strains 299s and 51s respectively. Doubling time is considerably shorter under these conditions than in the conventional static cultures. A 20-liter airlift bioreactor is described in detail which can be used successfully to otain up to 100 g wet weight of Paramecium in a single run; in this reactor the cell density reaches 38,000 cells/ml for strain 299s. and 23,000 cells/ml for 51s. This technic should facilitate the study of minor protein components of the ciliate.     

An updated angiosperm classification

DAHLGREN, C, 1989. An updated angiosperm classification. A new two-dimensional diagram, reflecting the system of classification of the angiosperms, is presented. It combines the dicotyledon diagram in G. Dahlgren (1989) and an adapted monocotyledon diagram after that in Dahlgren (1985) in a single diagram. An updated monocotyledon taxonomy is presented and the classification is appended.     

Effects of Ca2+ and Cd2+ on the Carbohydrate Metabolism in Sugar Beet (Beta vulgaris)

Sugar beet (Beta vulgaris L. cv. Monohill) were cultivated ina nutrient solution with different combinations of Ca²⁺ (36,180, 720 or 3560µM) and Cd²⁺ (0, 1, 5 or 20µM).The dry and fresh weights, the content of Ca²⁺ and Cd²⁺ , sucrose,fructose, glucose and starch in 5-week-old plants was analysedas well as the rate of [¹⁴C]-sucrose uptake in discs from 3-month-oldstorage roots. The carbohydrate metabolism was indirectly affectedby the presence of calcium or cadmium. Cadmium caused a diminisheddry weight and carbohydrate concentration. The dry weight wasunaffected by the Ca²⁺ level but the carbohydrate distributionbetween storage and growth processes was affected; at low Ca²⁺in the tissue, the growth was retarded and the level of storagecarbohydrate increased, while at high Ca²⁺ the opposite wasfound. The [¹⁴C]-sucrose uptake decreased in tap roots cultivatedat low Ca²⁺ . Long term exposure to Cd²⁺ also decreased thesucrose uptake in tap roots. Direct Cd²⁺ addition to the assaymedium, however, increased the sucrose uptake, probably at thetonoplast, while Ca²⁺ had no transient effect on the uptake.Cadmium increased the Ca²⁺ concentration in the plant, but Ca²⁺did not affect the net-uptake of Cd²⁺. Key words: Sugar beet, cadmium uptake, calcium uptake, carbohydrate formation, growth     

Variation in leaves and petals of Ranunculus subgenus Batrachium on the Aegean Islands, analysed by multivariate analysis

Variation in leaves and petals was studied using canonical variate and cluster analyseS. In total of 33 populations from eight islands leaf variation in laminar, floating leaves was studied in Ranunculus peltatus subsp. peltatus, subsp. baudotii and subsp. saniculifolius, and in R. Tripartitus, all of which are heterophyllous in the Aegean area. The petal data set also included the homophyllous R. Trichophyllus. The results of the analyses show that the populations are morphologically well differentiated and that petal shape has a tendency to discriminate between the populations somewhat better than leaf shape does. There was no basis for subdividing the populations into taxa on these characterS. Analyses showed that up to 70% of the variation was distributed between populations, the remainder (5–18%) being within populations.     

Relationship of Hypochaeris salzmanniana (Asteraceae, Lactuceae), an endangered species of the Iberian Peninsula, to H. radicata and H. glabra and biogeographical implications

Hypochaeris salzmanniana DC. (Asteraceae, Lactuceae) is an endangered species on the Iberian Peninsula, known from only eight coastal populations. Most authors have treated it as a variety, subspecies or simply as a synonym of H. glabra L. On the basis of morphological and cytological characters, Talavera recently separated H. salzmanniana (2n = 8) from H. glabra (2n = 10). Material of H. salzmanniana, H. glabra and H. radicata was collected from Spain, Italy, Sicily and Tunisia in order to assess taxonomic status and population relationships. Amplified Fragment Length Polymorphism (AFLP) analysis revealed three well-differentiated species. A close relationship between H. salzmanniana and H. radicata is also confirmed by AFLP analysis and chromosome number (2n = 8), morphology, and rDNA localization (FISH, fluorescence in situ hybridization). Hypochaeris salzmanniana and H. radicata share three fixed diagnostic AFLP fragments out of 348 fragments scored. The population structure of H. salzmanniana reveals distinct groups in southern Spain that are separated geographically. High differentiation among a western (Conil to Zahara), an intermediate (Punta Paloma and Los Algarbes) and an eastern (Algeciras and La Línea) group may reflect ancient separation. Population sizes and genetic compatibility differ greatly among populations and can be used to explain levels of within-population genetic diversity, together with recent documented loss of habitats resulting from tourist developments. Population structures of H. radicata and H. glabra show a similar geographical patterning: strongly differentiated populations from the Betic Cordillera and from the Iberian Massif, which are separated at present by the Guadalquivir river. Geological events at the end of the Tertiary (Tortonian–Messinian Miocene) might help explain patterns of differentiation in these three species of sect. Hypochaeris. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 146 , 79–95.