The fluctuations in the level of endogenous growth regulators in seeds ofAcer pseudoplatanus L. in the course of stratification

BoŽena GregorovÁ

Biologia plantarum 19:321-330, 1977 | DOI: 10.1007/BF02922726

In the course of cold stratification ofAcer pseudoplatanus L. fruits a statistically significant alternation occurs in their seeds of a rise and fall in the level of endogenous growth regulators. In the initial weeks the inhibitory effect slightly declines, or, on the contrary, the stimulatory effect slightly increases; in the middle phase of stratification a marked increase in inhibitions and reduction of stimulations appears, and towards the end of stratification the stimulatory effect of isolated substances in the individual biotests rises again, or their inhibition effect is decreased. No direct dependence was found between the decrease...

Changes in sulphate uptake and accumulation along the primary root during tissue differentiation

Margita Holobradá

Biologia plantarum 19:331-337, 1977 | DOI: 10.1007/BF02922727

Experiments were made with the uptake of 35-S sulphate along the axis of the intact seminal root of maize seedlings.Using short exposures the most intensive sulphur uptake was found in the apical 10 mm long region of the root. In the differentiating cells the maximum of sulphur uptake was in the first two 1-mm segments of the elongation zone immediately behind the meristem and then in the zone of the root hairs. Apart from the high activity in the area of the root hairs, two and three peaks, respectively, of increased sulphur accumulation were found in the area of the formation of laterals in case of longer exposure.

The influence of pretreatment with different cations on anaerobic nitrite production by excisedPisum sativum roots

J. Sahulka

Biologia plantarum 19:338-345, 1977 | DOI: 10.1007/BF02922728

The influence of pretreatment with some cations on anaerobic nitrite production (in an assay medium lacking nitrate) by excised primary roots of pea (Pisum sativum L., ov. Raman), detached from six-day-old seedlings germinated in distilled water, was investigated. When the excised roots were precultivated in one-salt-solutions of KNO3, then these roots produced at 9 mM and 15 mM NO3- concentrations under anaerobic conditions significantly more NO2-, than those precultivated in a nutrient solution containing besides K+ ions also Ca2+ and Mg2+ ions, and they produced nitrite for a longer time. The KNO3 dependent increase in anaerobic NO2- production...

Isolation from barley embryo of endonuclease specific for apurinic sites in DNA

J. Velemínský, Jiřina Švachulová, J. Šatava

Biologia plantarum 19:346-352, 1977 | DOI: 10.1007/BF02922729

The endonuclease activity specific for apurinic sites in DNA was detected in barley embryos. The enzyme was partially purified. It reveals high activity on partially depurinated DNA but low or nil activity on intact and alkylated DNA. The method used for the detection of enzyme activity was based on the changes in the sedimentation velocity of substrate DNA in neutral sucrose gradients with 80 % formamide.

Book review

J. Krekule

Biologia plantarum 19:352, 1977 | DOI: 10.1007/BF02922730

Regulation of seed germination and polarity in seedling development inOrobanche aegyptiaca by growth substances

Usha Kumar, N. S. Rangaswamy

Biologia plantarum 19:353-359, 1977 | DOI: 10.1007/BF02922731

InOrobanche aegyptiaca PEES. (Orobanchaceae) the mature seed is tiny and contains a subglobose embryo which is not differentiated into radicle, hypocotyl, plumule, and cotyledons. In aseptic seed cultures on medium TB supplemented with yeast extract or coconut milk, both roots and shoot originated from the morphological radicular pole of the embryo (monopolar pattern). The bipolar mode of seedling formation, that is a shoot originating from the plumular pole and roots from the radicular pole, ensued on the basal medium THS and on TB supplemented with certain concentrations of IAA, kinetin, GA3, or strigol.

Effect of toluidine blue on pollen germination and pollen tube growth

Sunanda Ghosh, K. R. Shivanna

Biologia plantarum 19:360-364, 1977 | DOI: 10.1007/BF02922732

Toluidine blue is known to induce gynogenic haploids in significant numbersin Populus]. Because the efficacy of a chemical in inducing gynogenesis depends largely on its effeot on pollen germination, on pollen tube growth, and on male gamete formation, the effect of toluidine blue (0, 1, 10 and 100 mgl-1) on these processes was studied in treated pistils ofSolatium nigrum (4 X), as well as on cultured pollen grains ofS. nigrum andTrigonella foenumgraecum.Irrespective of the time of application, toluidine blue (1 and 10 mg I-1) had no effect on pollen germination or pollen tube growth in pistils ofS. nigrum; at...

Protease activity during rice leaf senescence

M. Kar, D. Mishra

Biologia plantarum 19:365-369, 1977 | DOI: 10.1007/BF02922733

A protease activity was detected in rice (Oryza sativa L. cv. Ratna) leaves that hydrolysed hemoglobin more efficiently than bovine serum albumin. The activity was high when the enzyme was extracted and assayed with tris-maleate buffer [tris (hydroxymethyl) methyl amino-maleate] pH 7.0 rather than with water or with citrate-phosphate buffer pH 7.0. The enzyme had a strong dependence on sulfhydryl groups for its activity without which it was inaotive. The pH optimum was 7.0 and the temperature optimum was 40 °C. Protease activity expressed per unit leaf fresh weight (absolute activity) increased only little during senescence of detached rice...

The role of gibberellic acid (GA₃) in the removal of dormancy inFraxinus excelsior L. seeds

Barbara Wciślińska

Biologia plantarum 19:370-376, 1977 | DOI: 10.1007/BF02922734

The seeds ofFraxinus excelsior L. were stratified at 17-20 °C (warm stratification), at 4-6 °C (cold stratification) and at alternating temperature (warm - cold stratification). The seeds subjected to warm stratification only, remained dormant. The seeds stratified only at 4-6 °C germinated gradually during a long period of time. The seeds subjected to warm - cold stratification, however, germinated with great intensity within a relatively short period of time.GA₃ was shown to stimulate the growth of embryos markedly, and its effect on the germination of seeds depended on the temperature of stratification. GA₃ applied...

Book review

Ingrid Tichá

Biologia plantarum 19:376, 1977 | DOI: 10.1007/BF02922735

The differential effect of abscisic acid onChenopodium rubrum L. in dependence on growth and developmental state

Lola Teltscherová, Feideta Seidlová

Biologia plantarum 19:377-380, 1977 | DOI: 10.1007/BF02922736

According to plant age at induction and rate of initial growth ABA leads either to stimulation or inhibition of growth and flowering in youngChenopodium rubrum plants. This differential effect is linked with the morphogenetic potential of the plants at the time of ABA application. Different modes of germination and cultivation of the plants prior to floral induction affect growth and photoperiodic sensitivity of the plants which may also explain differences in the effect of ABA.

Book review

Ingrid Tichá

Biologia plantarum 19:386, 1977 | DOI: 10.1007/BF02922739

Book review

Vlasta Čatská

Biologia plantarum 19:390, 1977 | DOI: 10.1007/BF02922741

Book reviews

J. Brčák, A. Kotyk, Marie Ulrychová, Jana Pospíšilová, M. Kamínek, J. Tupý

Biologia plantarum 19:397-400, 1977 | DOI: 10.1007/BF02922744

Meiotic anomalies induced by x-rays inCapsicum annuum L.

K. Subhash, J. Nizam

Biologia plantarum 19:381-382, 1977 | DOI: 10.1007/BF02922737

Various types of meiotic anomalies in Mi generation such as multivalents, fragments, bridges, mioronuclei, polyads and in particular the multispindle formation, were observed after seed X-ray irradiation inCapsicum annuum L. As the dose increased there was a gradual increase in the number of aberrations.

Chalazal germination inTrichodesma amplexicaule Roth.

R. P. Bansal, D. N. SEN

Biologia plantarum 19:383-386, 1977 | DOI: 10.1007/BF02922738

Seed germination studies onTrichodesma amplexicaule were carried out. Seeds show abnormal behaviour of germination which is termed "Chalazal germination". This abnormal behaviour of germination is due to the presence of an obturator at the micropylar end. Seeds showed maximum (60 per cent) germination with 110 min concentrated H₂SO₄ treatment.

Localization of starch in shoot apices of vegetative and photoperiodically induced plants ofChenopodium rubrutn

Frideta Seidlová

Biologia plantarum 19:387-390, 1977 | DOI: 10.1007/BF02922740

Starch was determined by means of IKI reaction in shoot apices ofChenopodium rubrum plants induced to flowering by two short days and in non-induced plants. Small starch grains were already observed in the meristematic cells at an age of four days after sowing. Larger grains were found in the subapical region of the apex. Heterogeneity increases during further growth of the plants in induced, as well as in non-induced vegetative plants. Starch disappears from the cells potentially giving rise to axillary buds, while the number and size of starch grains increase in cells from which leaf primordia will be formed. This metabolic specifity of leaf...

The effect of different combinations of soil salinity and CCC on dry matter accumulation and yield of cotton plants

A. I. Gabr, S. A. El-Ashkar

Biologia plantarum 19:391-393, 1977 | DOI: 10.1007/BF02922742

CCC in either absence or presence of salinity slightly and irregularly affected the shoot dry weight, but consistently increased the seed cotton yield. The extent of such positive effect upon yield tended to be larger in the presence rather than in the absence of salinity when using CCC as a seed-soaking medium alone, but the reverse if applied as a spray after seed-soaking.

Effect of lunularic acid on auxin-oxidase activity

M. C. Mato, Rosa Calvo

Biologia plantarum 19:394-396, 1977 | DOI: 10.1007/BF02922743

Lunulario aoid was isolated from fresh thalli ofTargionia hypophylla L. This acid was found to enhanoe the destruction of IAA by auxin-oxidase from lentil roots. Such action can explain, at least partially, its inhibitory effect on IAA-induced plant growth.