Modification of the medium composition was a trial to improve germination and conversion in somatic embryos of Norway spruce. The mature embryos germinated for 1 week in the medium supplemented with either auxin (IAA, IBA, NAA ? 0.05; 0.25; 0.1 or 0.5 muM) or gibberellin (GA3, GA4+7 - 25; 50; 125 or 250 mg dm-3). The hormone-free medium used for the next 2 weeks of germination was enriched or not with activated charcoal (10 mg dm-3). The auxin applied in the medium did not affect embryo germination nor root and shoot growth. GA3 stimulated root and shoot growth in germinating somatic embryos, whereas the highest concentration of GA4+7 completely inhibited embryo germination.
Drying active baker's yeast in order to increase its storage life is aparticularly difficult process as yeast is a biologically active, easily degradable material.The present paper offers a method for drying baker's yeast on porous carriers.Experimental investigations proved that yeast dried on carriers is better quality than pure yeast dried in the same conditions.
The structure, dynamics and chlorophyll a content of lithoreophilous communities of Cyanobacteria and algae in two periodically drying sectors of the stream: in its upper (alpine ), and middle part (forest) zones were investigated. In both sectors the diversity of species was low. After snow melt, in the upper part, the stones were successively colonized by Cyanobacteria (with Chamaesiphon polonicus (Rostafinski.) Hansgirg prevailing), and green alga Klebsormidium rivulare (Kutz.) Starmach, finally obtaining stable and abundant communities. In the middle part of the stream, a spring explosion of Klebsormidium rivulare and species from the Chlorococcales group was observed. They developed temporary, since they disappeared after the June spate. Later this area was colonised mainly by Homoeothrix janthina (Bornet et Flahault) Starmach, Hydrurus foetidus (Villars) Trevisan, and diatoms, coming from a neighbouring non drying part of the stream. The chlorophyll a content in both sectors was low (2 - 55.8 mg m ?2) .
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