Types of the daily course of transpiration rate in seedlings of forest trees

M. Penka

Biologia plantarum 9:407-415, 1967 | DOI: 10.1007/BF02926982

Types of the daily course of transpiration rate were studied in two-year old seedlings ofPinus silvestris L.,Picea excelsa L.,Larix decidua L.,Tilia cordata Mill., andAlnus glu-tinosa (L.) Gaertn. The curves illustrating the daily development of transpiration rate (Figs. 3 - 8) may be grouped in two types, showing a midday maximum (one-peak curves) and a midday depression (two-peak curves). Unlike herbaceous plants, the seedlings ofPinus silvestris L. were found to show, during the night-time, lower but not negligible values for the rate of transpiration (see Figs. 3 and 8). The following times are considered...

Growth and nitrogen distribution in callus and crown-gall tobacco tissue cultures treated with kinetin and (2-Chloroethyl)trimethylammonium chloride (CCC)

Aldona Rennert, J. S. Knypl

Biologia plantarum 9:416, 1967 | DOI: 10.1007/BF02926983

1. Kinetin at a supra-optimal dose of 1.0 mg/l reduces the growth inhibitory effect of CCC at 5 × 10^-2 M on tobacco callus and increases it on tobacco crown-gall.
2. CCC increases the content of total, acid soluble, protein anti nucleic acid nitrogm in both tissues. Kinetin partially reduces the effects of CCC on nitrogem metabolism in callus tissue, and increases it in crown-gall.
3. It is suggested that (1) CCC affects the synthesis of RNA directing the synthesis of protein, and (2) interaction of kinetin with CCC realizes via the genetic apparatus of the cell.

Development and structure of foliage in wheat stands of different density

Danuše Hodáňová

Biologia plantarum 9:424-438, 1967 | DOI: 10.1007/BF02926984

The effect of sowing density (21, 85, 340 and 3400 plants per 1 m on the leaf area index (LAI), vertical arrangement of developing foliage and dry matter production was investigated in stands of wheat (Triticum aestivum L. cv. Niva).
1. With increasing sowing density.
a) The LAI increased and the highest LAI = 9.6 was obtained with 3400 plants. m-2. The largest development of foliage took place at ear emergence with 85, 340 and 3400 plants. rn-2, and in the flowering phase with 21 plants. m-2.
b) The overal leaf area duration was reduced, with a difference of 11 days between the lowest and the highest density.
c) The number...

Utilisation de la culture in vitro pour une étude du développement floral chez Anagallis arvensis L., ssp. phoenicea Scop.

Jeanne Brulfert, Denise Fontaine

Biologia plantarum 9:439-446, 1967 | DOI: 10.1007/BF02926985

Par la température de ľunique journée longue permettant la mise à fleurs chezAnagallis arvensis, il est possible do déterminer la formation do 2 types do boutons, par la suite, en jours courts: les uns évoluent en fleurs normales; les autres on fleurs proliféres - mais dans tune proportion do 50% seulement. Excisés précocement, à un stade de leur dévoloppement oè seuls, les sépales sont initiés, ces 2 types de boutons sont placésin vitro sur un milieu simple. Leur développement s'achéve, sur ce milieu, par la formation, soit de fleurs normales s'épanouissant, soit de fleurs proliféres dans la mêm proportion...

The Effect of Wilting on the Redox Potential of Cereal Leaves

J. Benada

Biologia plantarum 9:447-453, 1967 | DOI: 10.1007/BF02926986

The redox potential of wilted leaves of cereal seedlings grown in a greenhouse was higher than in the fresh leaves. However, the redox potential in the wilted leaves of plants during the stem extension was lower than in fresh leaves. The reaction of barley leaves var. Japan 2003, which belongs to the dundar-beyi Zhuk.-group, differed materially from the European cereal varieties. The cause of the change of redox potential is discussed in connection with the ontogeny of cereals and resistance against obligate parasites.

Cytoplasmic Components of the Broad Bean Root Tip Cells

A. F. M. Maniruzzaman, K. Beneš, J. Ludvík

Biologia plantarum 9:454-461, 1967 | DOI: 10.1007/BF02926987

The cytoplasmic components of broad bean (Vicia faba L.) root tip cells were studied light- and electronmicroscopically. Using a light microscope, differences were revealed between cells from the cortex and from the central cylinder. For electron microscope studies the cells near the boundary between the mentioned parts of the root tip were selected at a distance of about 2 mm from the initials. The orientation of objects during embedding made possible fairly accurate localization. No peculiar, strikingly osmiophillic bodies were seen, which could be identified without doubt as osmiophillic platelets. It follows that some of the current cytoplasmic...

Growth response to different constant soil moisture levels in maize (Zea mays L.) during the vegetative phase

J. Václavík

Biologia plantarum 9:462, 1967 | DOI: 10.1007/BF02926988

The effect of different constant soil moisture levels (90, 60, 30% and 90, 60, 40% respectively, of the maximum capillary capacity) on the vegetative growth of maize was studied by the methods of growth analysis. The constant soil moisture in vegetation pots was maintained by means of the injection method. The constantly decreased soil moisture was applied in one experiment just from the sowing of germinated corns and in the other from the phase of 4-6 leaves. In both the cases plants responded to the different soil moisture levels by a progressively lower growth rate of the total dry weight according to the degree of soil moisture lowering. When the...

The effect of secondary cosmic rays on spontaneous mutability

M. SOSNA

Biologia plantarum 9:473-475, 1967 | DOI: 10.1007/BF02926989