Dichotomie der mixoploiden Wurzelspitzen

Bohumil Němec

Biologia plantarum 7:1, 1965 | DOI: 10.1007/BF02920673

Einige durch Chloroalhydrat behandlung erzielte mixoploide Wurzelspitzen vonVicia faba verzweigen sich dichotomisch und es hat sich herausgestellt, dass die Dichotomie in jenen Wurzeln vor sich geht, welche einen polyploiden axialen Strang, der bis in das Transversalmeristem hineinragt, enthalten. Zu beiden Seiten dieses Streifens differenziert sich durch entsprechend orientierte Zellteilungen je ein neues Transversalmeristem. Wenn der polyploide Streifen nicht axial verläuft, so spaltet sich die Wurzelspitze in einen stärkeren weiter wachsenden und einen schwächeren, meist sein weiteres Wachstum einstellenden Teil. Da sich die polyploiden meristematischen...

Hybrid between tetraploid Phaseolus sp. And P. calcaratus Roxb.

S. Dana

Biologia plantarum 7:7, 1965 | DOI: 10.1007/BF02920674

1. In tetraploid Phaseolus sp. × P. calcaratus cross, shrivelled but viable seeds were produced. One hybrid was raised but it died within a month. Another hybrid was raised to flowering by artificially culturing the embryos before shrivelling.2. The F₁ of tetraploid Phaseolus sp. × P. calcaratus cross, had various leaf abnormalities at an early stage. In most of the characters the hybrid was intermediate between the two parents. The twining habit of P. calcaratus dominated in the hybrid. The F₁ plant had 10.7 per cent pollen fertility. The hybrid died within a week of flowering.3. In...

Attempts to diminish the injurious consequences of low winter temperatures by means of vitamins and growth substances

T. G. Kudrev, A. S. Tsenov

Biologia plantarum 7:13-19, 1965 | DOI: 10.1007/BF02920675

Plants of two varieties of winter wheat-Besostoya 1 and Etoile de Choisie- were raised in the field. The same number of selected plants from each variety were frozen once in a refrigerator at a temperature of -15°C for 24 hrs. After freezing, the plants were gradually thawed and returned to the field. Early in the spring, test and control plants were treated with one of following diluted solutions: vitamin B₁, vitamin B₆, indolyl-3-acetic acid and adenine (the four solutions at a concentration of 0.01% and 5% urea solution in water) by immersion for 15 hrs. at a temperature of 18-20°C. The plants were measured in the spring and...

Contribution to the study of heterogeneity in the leaves of a spring wheat plant

Miroslav Penka, Jiřina Srpová

Biologia plantarum 7:20, 1965 | DOI: 10.1007/BF02920676

The effect of the individual leaf blades of spring wheat on the dry matter of stalks, chaff and grain (caryopses), of spikes and total overground part, was studied. In the experimental plants the individual leaf blades were detached according to the scheme given, at the beginning of shooting, (A), at the beginning of earing (B), and at the beginning of flowering (C). The dry matter (fresh weight) of the stalk was least decreased if either the lowest or the uppermost leaf blade was severed during the developmental phase of shooting. The dry as well as the fresh weights of chaff were least affected in those plants where the leaf blade was removed during...

Studies on energy metabolism of germinating wheat seeds

S. J. Maleszewski

Biologia plantarum 7:31, 1965 | DOI: 10.1007/BF02920677

The amount of energy dissipated in the form of heat in the metabolic processes carried on during the initial period of the germination of wheat seeds was determined directy by means of an adiabatic microcalorimeter. The total energy simultaneously liberated in the respiration of the investigated seeds was calculated from the carbon-dioxide production. The proportion of total energy released in respiration to the amount of energy dissipated as heat indicates that about 5 per cent of respiratory energy is retained in the tissues of growing seedlings. The percentual rate of energy dissipated is not dependent on the temperature or the age of seedlings.

The activity of glutamic acid decarboxylase from intact wheat roots

Stanislav Tesař, Milan Kutáček, Zdenka Hromadová

Biologia plantarum 7:37, 1965 | DOI: 10.1007/BF02920678

Experiments with isolated wheat roots and with intact wheat plants showed that glutamic acid decarboxylase from the roots takes part in the transformation of substance in the medium and that its activity is influenced by the medium. Glutamic acid decarboxylase is thus a factor taking part in the formation of substances excreted by the plants roots.

Untersuchungen über die Photosynthese, Respiration und Transpiration des Maises unter Berücksichtigung von Unterschieden zwischen Populationen, Pflanzen, Blättern und Blattabschnitten

G. Meinl, K. Bellmann

Biologia plantarum 7:41, 1965 | DOI: 10.1007/BF02920679

Mit Ultrarot-Absorptionsschreibern für CO₂ und H₂O wurden die apparente Photosynthese, die Respiration und Transpiration von Maispflanzen und-blättern unter konstanten Bedingungen untersucht.Zwischen den 3 geprüften Sorten, "Schindelmeiser", "Siloma" und "WIR 25" ergaben sich keine signifikanten Sortenunterschiede hinsichtlich der apparenten Photosynthese obwohl sich die Sorten-bedingt durch die unterschiedliche Vegetationsdauer-in den Erträgen deutlich unterscheiden; die Einzelpflanzenstrenungen innerhalb der Sorten lagen bei 25%.Bei fast gleich grosser Einzelpflanzenstreuung innerhalb der Sorte zeigte sich eine signifikantBei...

The effect of 5-azacytidine on the root meristem ofVicia faba

V. Fučík, Z. Šormová, F. Šorm

Biologia plantarum 7:58-64, 1965 | DOI: 10.1007/BF02920680

The primary roots ofVicia faba seedlings were placed in a solution of 5-azacytidine and their further growth was observed after being replaced in running tap water. No inhibition of elongation occurred during the action of the 10^-5 M solution of 5-azacytidine for 24 hours, but during subsequent cultivation in water in the absence of inhibitor, further growth was blocked. This inhibition could be overcome by cytidine, uridine, sodium azide, 5-azidomethyluracil and simultaneously with the 5-azacytidine solution. Inhibition was accompanied by a high incidence of chromosome stickiness and to a less extent by an incidence of chromosome...

Research on substances inactivating the X virus present in sap from potato leaves

Evžen Jermoljev, Liana Albrechtová

Biologia plantarum 7:65-73, 1965 | DOI: 10.1007/BF02920681

The work ofJermoljev andBrčák (1964) showed that the sap of potato leaves contains substances inactivating X, Y and S viruses and that there was an increasing trend in the content of these substances in varieties resistant to these viruses. In further research it was found that potato tubers of varieties which are resistant and susceptible to the viruses contained the same amounts of inactivating substances. Differences in the power of inactivating the viruses evidently appeared in the leaves. Inactivating substances could be removed by boiling, they did not pass through a dialysing membrane and were adsorbed by animal charcoal. On centrifuging sap...

Etude du maintien de l'état vivacechezTeucrium Scorodonia L. (Labiée)

Claude Jouglard

Biologia plantarum 7:74, 1965 | DOI: 10.1007/BF02920682

1. Teucrium Scorodonia L., plante vivace et caulescente, doit être placèe à 3°C pendant 8 semaines au moins, pour être vernalisé.L'induction et l'initiation florales ont lieu en jours longs.2. Chez cette plante, l'état vernalisé est instable dans les bourgeons axillaires ainsi que dans le bourgeon terminal qui peut être dévernalisé, même après une réfrigération complètement vernalisante, par des photopériodes courtes ou par des températures élevées (35°C).D'autre part, la dévernalisation des bourgeons axillaires consécutive à l'inhibition de la croissance de ces bourgeons...

Über die Keimwurzelanzahl bei Weizen

Blanka Rovenská

Biologia plantarum 7:79-80, 1965 | DOI: 10.1007/BF02920683