Effect of different sugars on stomatal behaviour inMerremia aegyptia (L.) Urban andM. dissecta Hallier F.

S. S. Sharma, D. N. Sen

Biologia plantarum 18:81-87, 1976 | DOI: 10.1007/BF02923141

The effect of mannitol, glucose and sucrose on the stomatal behaviour of two desert species,Merremia aegyptia andM. dissecta has been studied. Stomatal opening did not uniformly depend on the decrease in turgor of the epidermal and subsidiary cells caused by the different osmotic potential of the sugars. Sucrose caused plasmolysis of the subsidiary cells only but this was not accompanied by the opening of the stomatal pore. InM. aegyptia, no plasmolysis was seen either in epidermal or subsidiary cells, even the stomata opened; inM. dissecta, on the other hand, plasmolysis occurred in these cells without any stomatal opening,...

Aphid transmission of Beet Yellows Virus affected by homologous antiserum

J. Brčák, J. Polák

Biologia plantarum 18:88-92, 1976 | DOI: 10.1007/BF02923142

A thin layer of homologous antiserum (against the beet yellows virus - BYV) between the leaf surface and a Parafilm membrane totally inhibited the acquisition of BYV by aphidsMyzus persicae (Sulz.), but it did not affect the inoculation of BYV by infective aphids. BYV transmission decreased with aphids picking up the virus from leaves coated with a normal rabbit serum. Aphids sucking on purified BYV suspension through the Parafilm membrane as well as aphids allowed to probe into leaves of healthy plants spread with an infectious purified BYV suspension failed to transmit BYV. No BYV particles could be detected in eluates from stylets and labia...

Book review

Ingrid Tichá

Biologia plantarum 18:92, 1976 | DOI: 10.1007/BF02923143

Effects of auxin, cytokinin, ethrel and cotyledon excision on the peroxidase activity in cotylar buds of decapitated pea (Pisum sativum L.) plants

J. Hradilík

Biologia plantarum 18:93-98, 1976 | DOI: 10.1007/BF02923144

In decapitated pea plants an increased peroxidase activity ocours after the cotyledon excision in cotylars growing in axillas of cotyledons prior to the growth of excised cotylars. It was found that peroxidase plays an important role in this correlation.
Auxin applied on epicotyl stumps inhibited the growth of cotylars and the removal of this inhibition by cytokinin or ethrel was associated with an increased peroxidase activity followed by the growth of cotylars situated in axillas of treated cotyledons.

The effect of potassium-deficiency on diamine oxidase activity in Pea

LibušE Paprskářová, J. Minář

Biologia plantarum 18:99-104, 1976 | DOI: 10.1007/BF02923145

Pea plants grown in nutrient solution in which K⁺ ions were equimolarly replaced with Na⁺, NH₄⁺ or Rb⁺ did not show morphological symptoms of potassium-deficiency. The activity of diamine oxidase in these plants was higher than in controls. Similarly higher diamine oxidase activity was found in plants grown in a complete nutrient solution supplemented with putrescine.

Book review

Ingrid Tichá

Biologia plantarum 18:104, 1976 | DOI: 10.1007/BF02923146

Improvement of the method of sap flow rate determination in full-grown trees based on heat balance with direct electric heating of xylem

J. Čermák, J. Kučera, M. Penka

Biologia plantarum 18:105-110, 1976 | DOI: 10.1007/BF02923147

Several improvements of the method of sap flow rate determination in full-grown trees elaborated by the authors are described. The method is based on heat balance with direct electrical heating of the xylem. The accuracy of the relationship for the calculation of flow rate was improved, the influence of unevennesses of flow in different annual rings was reduced. A method of extrapolation of the results obtained by measuring an individual xylem segment against the whole tree and of interpolation to a unit segment was elaborated, a simplified method of connecting the electrodes supplying the thermal input to the segment is described and an indicator...

Transpiration flow rate in a full-grown tree ofPrunus avium L. estimated by the method of heat balance in connection with some meteorological factors

J. Čermák, M. Palát, M. Penka

Biologia plantarum 18:111-118, 1976 | DOI: 10.1007/BF02923148

The course of the transpiration flow rate (Q_w), of transpiration flow acceleration (Q_w/dt) and of the integrated transpiration flow was determined during an average summer day by repeated measurements according to the method of heat balance and the free water capacity of the tree trunk was estimated. The relations between the transpiration flow rate and the temperature and relative humidity of the air and the vapour pressure deficit measured at the same time in their diurnal course, as well as at the single diurnal terms during the whole time at which measurements were carried out were determined by correlation analysis. The problems...

The effect of 2-thiouracil on RNA synthesis in pollen tubesof Nicotiana alata

J. SÜss, J. Tupý

Biologia plantarum 18:119-125, 1976 | DOI: 10.1007/BF02923149

The level of RNA in pollen is approximately 20 mg g^-1 and remains constant during 6 h pollen germinationin vitro also in the presence of 2-thiouracil which stimulates pollen tube elongation. The synthesis of RNA in pollen tubes was investigated according to the incorporation of the label from uracil-2-¹⁴C, 2-thiouracil-2-¹⁴C, orotic acid-5-³H, fructose-U-¹⁴C and from³²PO₄^3- into RNA fractions separated by methylated albumine kieselguhr chromatography. The distribution of radioactivity on elution profiles was different according to the radioactivity source,...

Book review

Blanka Úlehlová, Ingrid Tichá

Biologia plantarum 18:125, 1976 | DOI: 10.1007/BF02923150

Effects of kinetin and gibberellin a₃ on callus growth and organ formation inLimnophila chinensis tissue culture

R. S. Sangwan, B. Norreel, H. Harada

Biologia plantarum 18:126-131, 1976 | DOI: 10.1007/BF02923151

The action of exogenously applied hormones in the induction of morphogenesis inLimnophila chinensis (Osb.) Merr. tissue culture has been demonstrated. Stem expiants were grown on Murashige and Skoog's medium containing various levels of kinetin, gibberellic acid and indole-3-acetic acid. Formation of roots, shoots (normal or abnormal), plantlets and friable, hard or nodulated calluses depended largely on the hormone levels used. The formation of normal shoots and roots were stimulated by treatment with kinetin. GA₃ treatment stimulated the bud differentiation but inhibited the root initiation. A combination of kinetin and GA₃...

Effect of a lack of manganese on the structure and functioning of the photosynthetic apparatus of Funaria hygrometrica spores.

D. Chevallier

Biologia plantarum 18:132-139, 1976 | DOI: 10.1007/BF02923152

Funaria spores must structure their photosynthetic apparatus before germination. A lack of manganese in the culture media affects neither the final structure of chloroplast nor the chlorophyll synthesis. Fixation of CO₂, reducing power of chloroplasts (DPIP) and RPE photo-induced signal S II are modified by this lack of manganese. The study of Mn/Chl and CO₂ fixed/Mn ratios shows that Mn is a limiting factor for CO₂ fixation and that in the spores depleted of Mn the residual Mn is "structural" Mn.

On the nature of RNA synthesized in pollen tubes ofNicotiana alata

J. Süss, J. Tupý

Biologia plantarum 18:140-146, 1976 | DOI: 10.1007/BF02923153

The RNA formed in pollen tubes during 4 hours of growthin vitro was resolved by chromatography on methylated albumine on kieselguhr (MAK) into three principal fractions. Acoording to the labelling from uracil-¹⁴C about 11% was eluted with tRNA and 5 S RNA (low molecular weight RNA), 76% just after rRNA (D-RNA) and nearly 14% was recovered from the column by SDS at 35 °C (TB-RNA). In the presence of actinomycin D at concentration of 30 μg ml^-1 the synthesis of the three classes of RNA was inhibited by 71%, 97% and 70% respectively. On sucrose density gradient the radioactive low molecular weight RNA sedimented at 4 S-5...

Comparison of the effect of some phenolic compounds on wheat coleoptile section growth with their effect on iaa-oxidase activity

Ivana Macháčková, Z. Zmrhal

Biologia plantarum 18:147-151, 1976 | DOI: 10.1007/BF02923154

P-coumaric acid (HCA), 2,4-dichlorophenol (DCP) and resorcionol acted as cofactors for IAA-oxidase isolated from young wheat plants. Ferulic acid (FA) and 3,4-dihydroxybenzoic acid (DHBA) induced a lag phase prior to IAA oxidation. HCA, FA (0.2-1 mg ml^-1) and DCP (0.03-1 mg ml^-1) strongly inhibited wheat coleoptile section growth. DHBA (0.01-1 mg ml^-1) slightly stimulated it and resorcinol was without effect. HCA inhibited IAA-induced growth of coleoptile sections and FA stimulated it at low IAA levels and inhibited it at higher ones. DHBA, DCP and resorcinol did not affect IAA-induced growth of coleoptile sections.

Book review

Ingrid Tichá

Biologia plantarum 18:151, 1976 | DOI: 10.1007/BF02923155

Book reviews

Vlasta Čatská, Ingeid Tichá, J. Tupý, Věra Balatková

Biologia plantarum 18:158-160, 1976 | DOI: 10.1007/BF02923158

Studies on the physiology of hyacinth bulbs (Hyacinthus orientalis L.) the effect of plant growth regulators on metabolic activities in non-chilled hyacinth bulbs

Joanna Nowak, R. M. Rudnicki

Biologia plantarum 18:161-168, 1976 | DOI: 10.1007/BF02923159

The effect of gibberellic acid, benzyladenine and a mixture of these compounds on the activity of some hydrolytic enzymes was studied in hyacinth bulbs non-exposed to low temperatures. Plant growth regulators were applied on the heel of dormant bulbs in the middle of July. An intensive elongation of the inflorescence was observed only in the plants treated previously with GA₃ and grown in a warm greenhouse for 63 and 84 days. The activities of amylase, invertase and acid phosphatase were higher in the flower buds of unrooted bulbs treated with growth regulators than in the control plants, although growth regulators did not affect the level...

Book review

J. Brčák

Biologia plantarum 18:168, 1976 | DOI: 10.1007/BF02923160

Identification of alfalfa mosaic virus and tomato bushy stunt virus in hop (Humulus lupulus L.) and grapevine (Vitis vinifera subsp.sativa (DC./HEGI) plants in czechoslovakia

J. B. Novák, Julie Lanzová

Biologia plantarum 18:152-154, 1976 | DOI: 10.1007/BF02923156

In agreement with the results of biological tests with transmission to herbaoeous indicators and on orientation electron microscopic investigation, alfalfa mosaic virus (AMV) and tomato bushy stunt virus (TBSV) were serologically identified in the leaves of some of 8 samples of hop plants and of 17 bushes of grapevine, showing a complex of symptoms described in this paper. The latter reacted in double gel diffusion tests toPetunia strain but not to artichoke strain. The identification of these two viruses in grapevine is the first finding in Czechoslovakia, whereas in hop it is probably the first finding anywhere.

Size of stomata and palisade parenchyma on cotyledon adaxial side in someBrassica oleracea L. varieties

Jarmila Novotná, Blanka Rovenská

Biologia plantarum 18:155-158, 1976 | DOI: 10.1007/BF02923157

Cotyledons of 15 day-old seedlings of fiveBrassica oleracea L. varieties were surveyed to identify salient anatomical features. Both palisade parenchyma cells present in the first subepidermal layer and stomata were found to differ in size.