Kinetics of magnesium uptake by rice plants

N. K. Fageria

Biologia plantarum 18:169-172, 1976 | DOI: 10.1007/BF02922795

Uptake of magnesium was studied by continuous flow technique for 82 days old rice plants in nutrient solution over a range of 0.2 to 1 ppm or 8.2 to 41 µM magnesium concentration. Uptake of magnesium followed a Michaelis-Menten kinetics with a Michaelis constant, K_m of 0.2 × 10^-4M and V_m 156 µg g^-1 h^-1. With increasing flow rate, the rate of magnesium absorption was increased.

The effect of polyethylene glycol-induced water stress on the maize root apex

Milada Čiamporová, Mária Luxová

Biologia plantarum 18:173-178, 1976 | DOI: 10.1007/BF02922796

Following a 24-h exposure to a solution of polyethylene glycol 4 000 of a -12.66 bar osmotic potential the roots of maize ceased growing. The inhibition of growth was conditioned by the inhibition of cell elongation and division. The elongation of cells was substituted by their radial enlargement which took place both in the peripheral and central root parts. The cells either did not divide at all, or sporadic mitoses still occurred in the roots. The meristematic cells treated were highly vacuolized, chromatin condensation being observed in their nuclei. In contrast to growth processes, differentiation was stimulated: the formation of the secondary...

Inhibition of peroxidase by algal humic and fulvic acids

J. R. Pereira, J. Méndez

Biologia plantarum 18:179-182, 1976 | DOI: 10.1007/BF02922798

In contrast to their soil counterparts, algal fulvic acids were more inhibitory than the corresponding humic acids. Fulvic and humic acids fromFucus vesiculosus were more efficient than the correspondingLaminaria digitata acids in inactivating the enzyme.Laminaria humic acids, which have no phenolic hydroxyls, showed a concentration dependent inhibition hardly in accordance with the presumed role played by these groups in the activity of oxidases.

A kinetic study of phosphorus absorption by excised maize roots from flowing solutions influenced by 2,4 dinitrophenol and viscosity of solution

Radmila Čížková-Macůrková, Z. Laštůvka

Biologia plantarum 18:183-189, 1976 | DOI: 10.1007/BF02922800

The effect of 2,4 dinitrophenol and increased viscosity of the absorption solution on the absorption of phosphorus by excised roots of maize plants was investigated. The concentration of the solution was 0.1 mM KH₂PO₄, the activity of³²P was 52 µCi l^-1. The temperature of the absorption solution was 26 °C, pH 5.5, aeration prior to the experiment. There was 11 of solution for every 1 g of roots. Two basic variants were used for comparison: with non-flowing solution and with solution flow (circulation) of 0.162 cm s^-1, respectively. In all cases, 2,4 dinitrophenol reduced the rate of phosphorus...

Changes in respiration and BSMV concentration of infected wheat plants after treatment with 2,4-D

Olga Makovcová, L. Šindelář, Z. Polák

Biologia plantarum 18:190-194, 1976 | DOI: 10.1007/BF02922802

Changes in respiration, activity of cytochrome oxidase and ascorbic oxidase and in BSMV content were investigated on winter wheat plants cv. 'Kaštická osinatka' after application of growth stimulating and growth inhibiting concentrations of 2,4-D. It has been found that the rate of respiration is almost exclusively dependent on the activity of both these terminal oxidases. Consumption of oxygen was regularly increasing with decreasing herbicide concentration and at concentration 10^-7 M was even higher than the control value. Healthy and BSMV inoculated plants treated with 2,4-D differed in ascorbic oxidase activity while activity of cytochrome...

Activity of humus acids from peat as studied by means of some growth regulator bioassays

Hoang Kim Phuong, V. Tichý

Biologia plantarum 18:195-199, 1976 | DOI: 10.1007/BF02922803

Biologioal activities of humic acid (Na salt), hymatomelanic acid (Na salt), lignofulvic acid and of fulvic acids isolated from peat were studied by means of the auxin-, gibberellin-, and cytokinin- bioassays. All the four tested fractions showed higher or lower stimulating activity in these bioassays. However, the stimulating effect is considerably lower and cannot be interpreted as phytohormone activity. Some fractions in some concentrations also showed inhibitory effects. The manner of biological action of the studied fractions might bo the result of interaction of their respective components.

Atypical composition of seed proteins in cultivars ofPhaseolus vulgaris L.

Eva Klozová, J. Kloz, P. J. Winfield

Biologia plantarum 18:200-205, 1976 | DOI: 10.1007/BF02922804

In only one cultivar out of 1200 investigated cultivars ofPhaseolus vulgaris L. could we find an extreme change in the pattern of reserve proteins on the cathodic side: one of the proteins, called protein I, is completely absent in the cultivar 'Krupnaya sakharnaya' and is replaced on the same site by another protein,i.e. a protein completely different in its immunochemical specificity. The case is of interest from both the phylogenetic and systematic viewpoints and deserves further attention.

The influence of the fungicide folcidin on the distribution and metabolism of³²P in gherkin plants

I. Hanker, Anna Kůdelová, A. Friedrich, L. Taimr

Biologia plantarum 18:206-213, 1976 | DOI: 10.1007/BF02922806

High accumulation of³²P was observed in the leaves of intact gherkin plants 9 days after their roots had been treated with 0.005% suspension of the systemic fungicide Folcidin 50WP (cypendazole),i.e. 8 days after the roots had been exposed to labelled phosphate. Folcidin also influenced phosphorus metabolism in the plants. High biologic cytokinin-like activity of the fungicide was established when using a callus cytokinin bioassay.

The effect of calcium on the growth ofChlorella andScenedesmus

Jlřina DvOřáková-Hladká

Biologia plantarum 18:214-220, 1976 | DOI: 10.1007/BF02922808

The paper deals with the problem of the significance of Ca²⁺ for the growth of algae, its participation in the process of nitrate and ammonium nitrogen utilization, and with the possibility of substituting Sr²⁺ for it. It was revealed that calcium represents a microbiogenous element for the algae tested, which takes part in the utilization of nitrate nitrogen. It cannot be replaced by strontium especially at a high growth rate of mixotrophically cultivated algae (ina glucose medium).

Effect of different sugars on flowering ofChenopodium rubrum L. in dependence on the conditions of germination and initial growth

Lola Teltscherová, Dagmar Pleskotová

Biologia plantarum 18:221-226, 1976 | DOI: 10.1007/BF02922810

Flowering ofChenopodium rubrum seedlings fed different sugars at a concentration of 0.6 and 0.4 M, reap, during a single inductive cycle was stimulated or inhibited in dependence on the conditions of germination and initial growth. Plants allowed to germinate at alternating temperatures of 28 °C and 5 °C showed a slower initial growth and their development was stimulated by some sugars as compared to controls induced in the absence of sugars. Plants germinated at alternating temperatures of 32 °C and 5 °C exhibited a rapid initial growth and flowering was inhibited after induction in the presence of sugars. On the other hand, development proceeded...

Book reviews

Ingrid Tichá, Z. Opatrný

Biologia plantarum 18:229, 1976 | DOI: 10.1007/BF02922812

Salinity tolerance through seed treatment with proline

A. R. Bal

Biologia plantarum 18:227-229, 1976 | DOI: 10.1007/BF02922811

The treatment of rice seeds with 0.02% proline increased the germination under saline conditions.

Changes in Water Uptake in Light and Darkness of the Barley Cultivar 'Professor Schiemann' Infected with Powdery Mildew

S. Priehradný

Biologia plantarum 18:230-233, 1976 | DOI: 10.1007/BF02922813

In the investigated barley cultivar resistant toErysiphe graminis f. sp.hordei Marchal a temporary decrease in water uptake may be observed during the first days following infection in light. No marked differences could be detected in darkness. Starting from the stage of formation of fructification organs the ratio between water uptake in light and in darkness in the resistant cultivar is similar to that of the control, while the opposite is true in the susceptible cultivar where the ratio markedly decreases with the development of powdery mildew. The resistant cultivar responds more rapidly to the pathogen by changes in water uptake...

Kinetics of Chloroplast Contraction and Negative Phototaxis inMougeotia sp. Induced by High Radiant Flux Density

J. Hřib

Biologia plantarum 18:234-236, 1976 | DOI: 10.1007/BF02922814

Time-lapse microcinecmatography showed that the negative prototactic response of the chloroplast lasted 11-19 min and was completed 40 min after the beginning of irradiation; the contraction reached 11% in 60 min.

Contribution of Individual Leaves to Plant Photosynthesis During Plant Ontogenesis

Ingrid Tichá

Biologia plantarum 18:237-240, 1976 | DOI: 10.1007/BF02922816

Plants ofPlectranthus fructicosus were grown in two controlled environments -"spring" and "summer" conditions - differing in temperature and air humidity (day/night 20/15 and 27/22 °C; 80/98 and 50/80 % relative humidity) in order to study the influence of environmental conditions on the development of photosynthetic characteristics of individual leaves. The contribution of individual leaves to plant photosynthesis was very similar in both environments, the maximum shifting from bottom leaves to leaves of middle insertion levels during plant ontogenesis. On integrating the values of leaf photosynthesis for the whole vegetation period, the 5th...

Die photosynthetische Aktivitat, Mineralstoffernährung und Produktivität der Pflanzen

Ingrid Tichá

Biologia plantarum 18:178, 1976 | DOI: 10.1007/BF02922797

Environmental and biological control of photosynthesis

J. Čatský

Biologia plantarum 18:182, 1976 | DOI: 10.1007/BF02922799

Allfemeine Biologie. Eine Einführung für Biologen und Mediziner

Ingrid Tichá

Biologia plantarum 18:189, 1976 | DOI: 10.1007/BF02922801

The chemistry and biochemistry of plant proteins

Eva Klozová

Biologia plantarum 18:205, 1976 | DOI: 10.1007/BF02922805

Phytotronics III phytotronics in agricultural and horticultural research

J. Krekule

Biologia plantarum 18:213, 1976 | DOI: 10.1007/BF02922807

The germination of seeds

Vlasta Čatská

Biologia plantarum 18:220, 1976 | DOI: 10.1007/BF02922809

Ion transport in plant cells and tissues

Z. Šesták

Biologia plantarum 18:236, 1976 | DOI: 10.1007/BF02922815