Biologia plantarum, 1966 (vol. 8), issue 5

Article

Über die Wirkung von Wasserextrakten aus der Blattlaus Brachycaudus napelli Schrk. auf abgeschnittene Tomatenpflanzensprosse

Václav Kazda

Biologia plantarum 8:347-353, 1966 | DOI: 10.1007/BF02930671

1. Wasserextrakt aus zerriebenen BlattläusenBrachycaudus napeli Schrk. verursachte in Verdünnungen von 1∶9 und 1∶25 an abgeschnittenen und in die Extrakte gestellten Tomatensprossen Welkeerscheinungen, d. h. das Welken und Einrollen der Fiederblätter, das Welken der Blattstiele und der Gipfelblätter. Die Wirkung stärker verdünnter Extrakte und solcher, die durch den Bakterialfilter filtriert wurden, war schwächer.2. Durch Versuche unter normalen und konstanten Bedingungen wurde festgestellt, dass Wasserextrakte aus derselben Blattlausart in Verdünnungen 1∶9 und 1∶25 eine wesentliche Hemmung der Wasseraufnahme...

Utilization of organic substrates during mixotrophic and heterotrophic cultivation of algae

J. Dvořáková-Hladká

Biologia plantarum 8:354, 1966 | DOI: 10.1007/BF02930672

Pure cultures ofChlorella pyrenoidosa (82) andScenedesmus obliquus (125) were grown in the nutrient medium according to Benson in the presence of 0.05m sugars or 0.025m sodium salts of organic acids. The density of culture was measured throughout the course of growth. Satisfactory heterotrophic sources of nutrition forChlorella pyrenoidosa appear to be galactose, glucose and acetate, whereasScenedesmus utilizes glucose, cellobiose and acetate. The growth ofChlorella in the light is enhanced by galactose, glucose, fructose, cellobiose and maltose, that ofScenedesmus by glucose, fructose, cellobiose, galactose,...

Sorption of some ions by algae related to their trophic conditions

M. Dvořák, Jiřina Dvořáková-Hladká, Svatava Fialová

Biologia plantarum 8:362, 1966 | DOI: 10.1007/BF02930673

The unicellular algaeScenedesmus obliquus (125),Chlorella pyrenoidosa (82) andCoccomyxa solorinae saccatae (111) were studied with respect to the form of uptake of potassium, phosphate, calcium and zinc ions and to the energy sources involved: light under autotrophic conditions, glucose under mixotrophic or heterotrophic conditions (in light and in darkness or together with yeast extract as an auxotrophic substrate). We respected the trophic conditions of algae when preparing the experimental material (precultivation). The following conditions were reached:(1) The three algae grow faster in a glucose medium under mixotrophic...

Spiral feedback oscillations of growing hypocotyl with radicle inPisum sativum L.

M. Spurný

Biologia plantarum 8:381, 1966 | DOI: 10.1007/BF02930674

Cinematographic records of longitudinal growth showed that hypocotyl with radicle inPisum sativum L. undergoes spiral oscillations during growth. This phenomenon can be characterized by the following time-space limits:(1) Curvature of the hypocotyl with radicle takes place always in the zone of most rapid elongation (Fig. 2, 8).(2) Maximum deflections of the root tip from a straight positive geotropic direction of growth correspond to the time when the maximum growth rates were demonstrated (Table 4, Fig. 8).(3) Shift of zones of maximum elongation proceeds in a spiral path, acropetally to the region of the root tip; as may be seen...

Preventive effect of inhibitors from potato leaves on local infection with virus X

Evžen Jermoljev, Jaroslav Brčák

Biologia plantarum 8:393-397, 1966 | DOI: 10.1007/BF02930675

Substances inhibiting local infection with virus X were isolated from leaves of potato cultivars Saphir, Saco, and Blaník by means of ultracentifugation and were concentrated with ammonium sulphate. These inhibitors were effective if rubbed into leaves of some host plants at least 2-4 days prior to infection without using any abrasives.

Synthesis of protein and RNA in pollen tubes stimulated with 2-thiouracil

Jaroslav Tupý

Biologia plantarum 8:398, 1966 | DOI: 10.1007/BF02930676

1. Protein synthesis in pollen tubes ofNicotiana alata Link etOtto estimated by the incorporation of leucine-¹⁴C is linear over six hours of artificial cultivation after a short lag phase. 2-Thiouracil and other growth-stimulating antimetabolites of natural pyrimidines and purines, such as 6-azauracil, 5-nitrouracil, 8-azaguanine and 8-azaadenine, stimulate the incorporation of leucine-¹⁴C into protein. The intensity of stimulation of protein synthesis is associated with the intensity of growth stimulation by antimetabolite.2. Synthesis of RNA is inhibited by 2-thiouracil (according to the incorporation of uracil-¹⁴C,...