Diploidisierung und Polyploidisierung mixoploider Wurzelspitzen

Bohumil Němec

Biologia plantarum 6:161, 1964 | DOI: 10.1007/BF02926672

Wenn sich polyploide Zellstrange oder Sektoren an der Peripherie der Wurzelspitze befinden, so können Initialen, durch deren Teilung sie entstanden sind, ihre weitere Teilung einstellen, und die polyploiden Zellenstränge werden durch Verschleimung der Zellmembran abgetrennt. Es ist ein Chorisevorgang, analog der Abschälung der lateralen Haubenschichten. Nur werden in mixoploiden Wurzelspitzen polyploide Zellstränge abgetrennt, die allerdinga auch vereinzelte diploide Zellstränge enthalten können. Der Vorgang kann zur Diploidisierung der Wurzelspitze wesentlich beitragen. Seltener kann eine Wurzelspitze, wenn sie eine starke Majorität von polyploiden...

Study of a papain activation factor present in the dialysable fraction of soyabean extract

Krishna Bahadur, Indra Saxena

Biologia plantarum 6:165, 1964 | DOI: 10.1007/BF02926673

Soyabean extract contains an activator which passes through parchment paper. The increase in the activity of a mixture of urease and papain with increasing amount of papain in the mixture is due to the increase in the non-dialysable fraction of papain.

Changes in crossing over frequency in barley caused by different concentrations of calcium and magnesium

Miloš Ondřej

Biologia plantarum 6:171, 1964 | DOI: 10.1007/BF02926674

The linkage of barley between rough versus smooth awns and long versus short rachilla hair was influenced by different amounts of Ca and Mg. It was found, that not only lack, but also excess causes an increase of the recombination frequency as against the control.

Inhibition of respiration by sodium fluoride and monoiodoacetic acid in wheat leaves at different oxygen tensions and in the presence of methylene blue and L-cysteine

Marie Krejcarová

Biologia plantarum 6:175, 1964 | DOI: 10.1007/BF02926675

Six-day leaves of wheat (Triticum vulgare) were used to test the effect of oxygen, nitrogen and different mixtures of these gases, methylene blue and L-cysteine on the inhibition of respiration by sodium fluoride and monoiodoacetic acid using the Warburg manometric method. In an atmosphere of 100% oxygen total respiration was increased by an average of 45%, 10% oxygen led to a decrease in respiration by 20%. However, no simultaneous changes were found in the degree of inhibition by these enzyme poisons. On decreasing the oxygen content to 5% inhibition of respiration was almost doubled while at the same time respiration fell by an average of...

The effect of humic acid on transamination in winter wheat plants

Alena Činčerová

Biologia plantarum 6:183, 1964 | DOI: 10.1007/BF02926676

A very low, for the most part unmeasurable glutamic-aspartio transminase activity and a very high glutamic-alanine transaminase activity was found in the overground parts and roots of young wheat plants. The roots had a higher glutamic-alanine transaminase activity than the overground parts in the first and second leaf stage.Plants cultivated in Knop's nutrient solution (variant with humate and without) showed a higher glutamic-alanine transaminase activity than poorly growing plants, cultivated in distilled water (with humate and without). In plants cultivated in nutrient solutions, transaminase activity increased with the age of the wheat plants.As...

Physiology of the cold-resistance of maize during Germination. the reaction of maize (Zea mays L.) to low temperature during germination and its cold-resistance

Vladimír Segeťa

Biologia plantarum 6:189, 1964 | DOI: 10.1007/BF02926677

Attempts to elucidate the physiological basis of cold-resistance during germination led to the investigation of the germination of seeds at low temperature, the effect of pathogenic and parasitic microorganisms being excluded.At the various experimental temperatures (4°, 6°, 8°, 10° and 14°C) it was found that seed samples of different varieties of maize respond to conditions close to the temperature minimum for germination in three quantitatively different ways. Firstly, caryopses germinate considerably later than at higher temperatures, secondly, the kernels will not germinate even after a prolonged period, without losing their viability and,...

Respiration of intact and damaged plants ofSpirodela oligorhiza SCHL

Jiřina Dvořáková-Hladká

Biologia plantarum 6:198-201, 1964 | DOI: 10.1007/BF02926678

The wound effect ("Wundeffekt") was investigated inSpirodela oligorhiza by comparing respiration in intact plants and plants cut into halves and quarters. The effect of damage was not evident immediately after injury but after 18 hours the respiratory rate of cut plants was twice to three times that of intact plants. The increased respiration rate is, therefore, not the direct result of mechanical injury.

The modification of antigenic properties of tissues during seed germination and development of horse bean plants (Vicia faba)

V. Ghetie, L. Buzila

Biologia plantarum 6:202, 1964 | DOI: 10.1007/BF02926679

It was shown that in the horse bean seeds (Vicia faba) the cotyledon proteins are identical, from an immunochemical standpoint, with those coming from the extracotyledon parts (radicle, young stem and embryonal leaves, in totality). However, the beginning of the germinative process exerts a different influence on the antigenic properties of the constitutive parts of the seed. The modification of the antigenic structure in cotyledons takes place slowly. On the contrary, in the extracotyledon parts a rapid decrease was found of the number of antigens present in the non-germinated seed. As the organs become differentiated, the hydrolysis process...

Randomization of carbon atoms in the glucose molecule and changes of specific radioactivity of¹⁴CO₂ liberated by the callus tissue ofDaucus carota L. from glucose-6- and -1-¹⁴C

Jiří Luštinec, Věra Hadačová-Pokorná, Miroslav Kamínek, Jack Edelman, Eva Petrů

Biologia plantarum 6:209, 1964 | DOI: 10.1007/BF02926680

On incubation of the callus tissue ofDaucus carota L. in solutions of glucose-6-¹⁴C and -1-¹⁴C the distribution of radioactivity in the molecule of endogenous glucose will change and the ratio of activities of liberated¹⁴CO₂ (C₆/C₁) will rise The limits of possible changes of specific activity of¹⁴CO₂ and of the C₆/C₁ ratio were calculated with respect to the observed randomization and it was shown that the mutual exchange of carbon atoms in the molecules is not the decisive cause of the rise of the ratio.The specific radioactivity...

The anatomy of the shoot apex of wheat (Triticutn aestivum L.) during transition from the vegetative to the reproductive state and the determination of the primordia

J. Opatrná, F. Seidlová, K. Beneš

Biologia plantarum 6:219, 1964 | DOI: 10.1007/BF02926681

An investigation was made of the anatomical structure of the shoot apex of wheat in the first four stages of organogenesis according toKuperman (1961). It was found that the shoot apex is first covered only with dermatogen (first stage). Then the hypodermis gradually differentiates (second stage) followed by differentiation of the subhypodermis (third stage). In the first stage, the central core of the apex is formed by more or less uniform isodiametric cells so that no zones are distinguishable. During the initiation of the primordia of the assimilating leaves, i.e. in the second stage, a group of larger cells was observed in the apical part of the...

Changes in the anatomical structure of the shoot apex ofSenecio vulgaris L. during ontogenis in relation to the formation of leaves and inflorescence

Frideta Seidlová, Bořivoj Hořavka, Jana Opatrná, Jan Krekule

Biologia plantarum 6:226, 1964 | DOI: 10.1007/BF02926682

An investigation was made of the anatomical structure of the shoot apex ofSenecio vulgaris L. a photoperiodically neutral plant, and compared with the formation of successive leaf primordia along the axis up to the initiation of the terminal inflorescence. In the shoot apex of a germinating plant a central zone can first be distinguished from the peripheral zone which is composed of small and intensely stained cells. Later, a rib meristem appears. At the time of the initiation of the middle (the largest) leaves, the shoot apex has a distinct small central zone and a well developed peripheral zone and rib meristem. Between these zones there is...

Enzymatic synthesis of 5-bromo-2'-deoxyuridine-2-¹⁴C and of 5-iodo-2'-deoxyuridine-2-¹⁴C and their incorporation into deoxyribonucleic acid (Allium cepa)

V. Fučík, J. Káká

Biologia plantarum 6:232-235, 1964 | DOI: 10.1007/BF02926683

5-Bromo-2'-deoxyuridine-2-¹⁴C was prepared from 5-bromouracil-2-¹⁴C and 2'-de-oxyguanosine using trans-N-deoxyribosylase fromLactobacillus helveticus and incorporated into DNA ofAllium cepa roots. After isolating the DNA and hydrolyzing it enzymatically to deoxynucleoside-5'-phosphates a radioactive nucleotide was detected which yielded 5-bromo-2'-deoxyuridine-2-¹⁴C on enzymatic dephosphorylation. The incorporation of 5-iodo-2'-deoxy-uridine-2-¹⁴C was followed only by microautoradiography.

Gibberellin and sympodial branching inTilia

Rudolf Dostál

Biologia plantarum 6:236-237, 1964 | DOI: 10.1007/BF02926684

Preservative effect of saccharose solution on some plant viruses

Zdenko Polák

Biologia plantarum 6:238-239, 1964 | DOI: 10.1007/BF02926685

The identification of hybrids ofPhaseolus vulgar is L. ×Phaseolus coccineus L. Using immunoehemical methods

Eva Klozová, Josef Kloz

Biologia plantarum 6:240, 1964 | DOI: 10.1007/BF02926686