Substances of plant flowering

M. Kh. Chaïlakhyan

Biologia plantarum 17:1-11, 1975 | DOI: 10.1007/BF02921064

The investigation of the hormonal nature of plant flowering in connection with their photoperiodic reaction has shown that flowering depends on a bicomponental system of hormones, gibberellins regulating stem formation and growth and substances of the anthesin type regulating flower formation. In agreement with the division of the photoperiodic reaction into a leaf and a stem phase the study of the internal factors acting on plant flowering was carried out by means of leaf and stem (apex, bud and callus) models. The results obtained from work with leaf models proved the presence of two groups of hormones of flowering in plants. The data obtained from...

Dynamics and some characteristics of natural free cytokinin content in growing apices of apple tree shoots during the vegetative season

A. Friedrich, L. Chvojka

Biologia plantarum 17:12-16, 1975 | DOI: 10.1007/BF02921065

The changes of content and some chromatographic characteristics and biological activities of natural free cytokinins were studied during the vegetation season in the growing apices of apple tree shoots. Biological cytokinin activity was discovered in two groups of compounds differing in the time of their biological actions. Rf values and in the time of their maximal content in the growing apices. The time of maximal content was in accordance with their biological activity.

Tuberization, dormancy and in situ RNA synthesis in jerusalem artichoke (Helianthus tuberosus L. cv. D-19)

M. Gendraud

Biologia plantarum 17:17-22, 1975 | DOI: 10.1007/BF02921067

In Jerusalem artichoke tuber,in situ RNA synthesis along vegetative cycle shows two maximums. The first one appears during tuberization and installation of dormancy and a growth inhibition is sufficient to bring it about. The second reveals breaking of dormancy and precedes germination.

Auxin decarboxylation and isoperoxidases in strawberry petiole extracts

Th. Gaspar, M. Dubucq, R. Antoszewski

Biologia plantarum 17:23-30, 1975 | DOI: 10.1007/BF02921068

Most of the peroxidase activity of strawberry petiole is obtained from ionic treatment and pectinase-cullulase digestion of the cell-walls: two ionically-and three covalently- bound isoperoxidases were separated by starch gel electrophoresis. A technique is described for preparing an active IAA-oxidase extract. Final oxidation products of indoleacetic and indoleacrylic aeids appear to be the most effective IAA-oxidase promoters.

Influence of zeatin on respiration and photosynthesis of mesophyll protoplasts ofPetunia

U. Kull, F. Hoffmann

Biologia plantarum 17:31-37, 1975 | DOI: 10.1007/BF02921070

Application of 1 ppm zeatin raises the respiration rate (measured by the Warburg method) of leaf mesophyll protoplasts ofPetunia hybrida by about 50% after 4 h; afterwards there is a rapid decrease. While the rate of respiration in the controls rises after 5 to 6 h, 1 ppm zeatin has a strong inhibitory effect. When the protoplasts are incubated with 0.1 ppm zeatin the rise in the rate is much slower, and after 7 h the rate is 30% higher than in the controls. Abscisic acid (10 ppm) decreases the respiration rate so that after 5 h it is less than half that of the controls. Later on there is a rise as in the controls, perhaps caused by senescence...

Manometric estimation of respiration of isolated protoplasts ofPetunia

F. Hoffmann, U. Kull, I. Potrykus

Biologia plantarum 17:38-42, 1975 | DOI: 10.1007/BF02921071

Respiration of protoplasts isolated from the leaf mesophyll ofPetunia hybrida was estimated by the Warburg method. The time course of respiration rate shows an initial decrease followed by a prominent increase which is caused by shaking of the protoplast suspension. The absolute respiration rates are low and show an unusual spread, but the temporal form of the curve is always similar to that one shown in Fig. 1.
The RQ-values shift from below 1 during the initial phase to far above 1 during the increase of the respiration. For isolated protoplasts from petals the same is true. Feeding the protoplasts with DNA does not influence the respiration...

Elongation and circumnutation oscillations of hypocotyl of pine seedlings (Pinus silvestris L.)

M. Spurný

Biologia plantarum 17:43-49, 1975 | DOI: 10.1007/BF02921073

The elongation of pine seedlings (Pinus silvestris L.) is associated with nutation movements. Trajectories of these growth oscillations were recorded by film technique in horizontal and vertical projection during a three day period of growth. On the basis of these data the parameters of elongation and nutation oscillations,i.e. rate, amplitudes and frequency of oscillations, were calculated and their changes during plant development compared. Oscillation trajectories are circular or elliptic spirals the amplitudes of which are increasing with the age of hypocotyl from 1.5 mm to 7.5 mm. The frequencies of nutations are decreasing during...

The serological specificity of S alleles of homozygous incompatible lines of the marrow-stem kale (Brassica oleracea var.acephala DC.)

V. Kučera, J. Polák

Biologia plantarum 17:50-54, 1975 | DOI: 10.1007/BF02921074

The preparation of antisera against S alleles of homozygous incompatible lines of the marrow-stem kale (Brassica oleracea var.acephala DC.) is described. The antisera obtained reacted specifically with homologous antigens on using the serological method of double diffusion into agar. The results confirmed the specificity of S alleles of incompatible lines of the marrow-stem kale.

Kinetics and implications of seedling growth responses to 2-chloroethylphosphonic acid

N. O. Adedipe

Biologia plantarum 17:55-59, 1975 | DOI: 10.1007/BF02921075

The effects of soaking seed in 2-chloroethylphosphonic acid (CEPA) for 24 or for 48 h on the cumulative 5-day seedling growth ofCucumis sativus L. (cucumber) andPisum sativum L. (peas) were studied. Each cucumber seed absorbed an average of 0.015 ml of CEPA solution, while pea seed absorbed 0.365 ml, over a 24 h period.
In cucumber, 240 mg l^-1 CEPA concentration decreased radicle length by 23%, regardless of soaking duration. The same concentration increased radicle weight in a 24 h soaking duration, but decreased radicle weight when soaking was for 48 h. At 48 h, CEPA concentrations of 0.24 and 2.4 mg l^-1 increased...

Streptomycin induced changes in growth and metabolism of etiolated seedlings

S. Mukherji, Archana Bag, A. K. Paul

Biologia plantarum 17:60-66, 1975 | DOI: 10.1007/BF02921076

Effects of various concentrations of streptomycin sulphate either alone or in combination with different cations and hormones on mungbean (Phaseolus aureus L.) seedling growth were studied. The relative inhibition of root growth was stronger than that of hypocotyl growth. Root growth inhibition was completely overcome by calcium, while other cations were ineffective. Inhibition of hypocotyl elongation could not be prevented by cations. IAA and GA₃ were capable of relieving streptomycin inhibition but kinetin was ineffective.
In the coleoptiles of streptomycin-treated rice (Oryza sativa L.) seedlings, there were accumulation...

Histochemical investigation of dehydrogenases in shoot apices of wheat plants at different ontogenetic stages

Jana Opatrná

Biologia plantarum 17:67-74, 1975 | DOI: 10.1007/BF02921077

The activity and localization of alcohol (AD), lactic (LD), malic (MD), isocitric (ICD) and succinic (SD) dehydrogenase, resp. was histochemically determined in shoot apices of plants in the vegetative condition during transition to flowering and at the reproductive state. The enzymes were determined in freehand sections, as well as in shoot apices incubatedin toto according toNachlaset al. (1958) using Nitro-BT. The characteristic localization of the enzymes depending on the ontogenic stage of the shoot apex is described. Different parts, layers and cell groups of the apex showed differences in enzyme activity. SD could not be detected...

Beek, J., Frissel, M. J.: Simulation of nitroyen behaviour in soils

F. Pospíšil

Biologia plantarum 17:16, 1975 | DOI: 10.1007/BF02921066

Walter, Heinrich: Vegetation of the earth in relation to climate and the eco-physiological conditions

Jiřina Slavíková

Biologia plantarum 17:30, 1975 | DOI: 10.1007/BF02921069

Maksymowych, R.:Analysis of leaf development

Ingrid Tichá

Biologia plantarum 17:42, 1975 | DOI: 10.1007/BF02921072

A device for the measurements of radiation in stands with automatically moving sensors

J. Vidovič

Biologia plantarum 17:75-78, 1975 | DOI: 10.1007/BF02921078

The construction of the track for automatic, continuous horizontal transporting of the sensor which measures radiation with controlled velocity at various heights above the ground in a plant stand has been described.

Intercellular communication in the maize root endodermis

Albína Klasová

Biologia plantarum 17:79-80, 1975 | DOI: 10.1007/BF02921079

The endodermal cells of the maize roots are linked to each other via plasmodesmata mainly localized at the proximity of the Casparian band on the anticlinal walls. In this part of the walls was noticed the absence of the suberin lamella in the thickening endodermal cells.