Purification, electron microscopy and serology of virus isolated fromEuonymus europaea

Valéria Šubíková, Helena Baumgartnerová, V. Bojňanský

Biologia plantarum 1974, 16:321-324 | DOI: 10.1007/BF02920991

"Euonymus mosaic virus", purified from cucumber cotyledons by the differential and density-gradient centrifugation, shows typical nucleoprotein absorption spectrum. Electron microscopy reveals isometric virus particles of about 37 nm diameter. No reaction of purified "Euonymus mosaic virus" was observed with antisera against a raspberry ringspot virus, tobacco ringspot virus, cherry leaf roll virus, strawberry latent ringspot virus, tomato ringspot virus, elm mosaic virus, arabis mosaic virus, tomato bushy stunt virus and watermelon mosaic virus.

Control of RNA level and of RNA ratios in the latex ofHevea brasiliensisMüll. Arg. effect of latex tapping and of growth regulators

J. Tupý

Biologia plantarum 1974, 16:325-333 | DOI: 10.1007/BF02920992

The association between latex RNA and latex production was examined using MAK column chromatography techniques. In young untapped trees the introduction of tapping or the treatment of bark with growth regulators resulted in an increase of RNA level and of rRNA/tRNA ratio in the latex. In regularly tapped trees an increase in rRNA but not in tRNA was brought about by increasing the tapping frequency. Treatment with growth regulators had the same effect but essentially only through the related enhancement of latex export from latex vessels. During latex flow, the highest RNA level was registered in latex fractions originating from the most heavily drained...

The influence of cytokinins on apple embryo photosensitivity and acid phosphatase activity during stratification

St. Lewak, Barbara Bryzek

Biologia plantarum 1974, 16:334-340 | DOI: 10.1007/BF02920993

Kinetin (KIN) and benzyladenine (BA) stimulate to different extent the germination of apple embryos isolated from dormant seeds or seeds submitted to stratification. KIN is much more active in the replacement of light requirement in apple embryos germination. Both cytokinins decrease the photosensitivity of embryos isolated from the seeds stratified less than one month, but only BA accelerates the appearance of the second photosensitivity maximum, normally occuring on the 70th day of stratification. Both cytokinins stimulate the activity of acid phosphatase between the 30th and 50th day of apple seed stratification. The stimulation between the 50th...

Investigation of the endogenous rhythm of flowering in Chenopodium rubrum L.

Lola Teltscherová, Jana Opatrná, Dagmar Pleskotová

Biologia plantarum 1974, 16:341-347 | DOI: 10.1007/BF02920995

Under the conditions applied in our laboratory 4 1/2 days old plants ofChenopodium rubrum require 2-3 photoperiodic cycles for maximal flowering response, whereas 2 1/2 days old plants are able to flower after having obtained a single inductive cycle. The period length of the free-running rhythm of flowering observed in 2 1/2 days old plants after a single transfer from light to darkness is 30h and the first peak of flowering occurs at about hour 12 in darkness. When a cycle consisting of 16h darkness and 8h light or of 8h darkness and 8h light precedes the long dark period the rhythm is rephased. Rephasing is greater when the light commenced...

The effect of age on the photosynthetic rate inPrunus laurocerasus L. leaf discs

L. Halás

Biologia plantarum 1974, 16:348-354 | DOI: 10.1007/BF02920996

The photosynthetic rate in leaf discs (P_LD) ofPrunus laurocerasus L. plants taken up from leaves of various ages was measured under constant temperature (20±0.5°C) CO₂ concentration in air (0.03%) complete water saturation and irradiance (71 W m² PhAR). TheP_LD is the highest in mature leaves of the current year. The extent of depression in the second and further years depends on the degree of habitat shading. In a slightly shaded habitat (60 to 73% daily sum of photosynthetically active radiation-PhAR) it decreases by almost 50% in the second year. In a deeply shaded habitat (22.5-28.2%...

Changes in the transpiration rate of barley plants cv. "Profesor Schiemann" infected with powdery mildew in light and in darkness

S. Priehradný

Biologia plantarum 1974, 16:355-358 | DOI: 10.1007/BF02920997

The transpiration rate of intact spring barley plants, cv. Profesor Schiemann resistant to powdery mildew was studied separately in light and in darkness. At the first stage of pathogenesis the fungus temporarily reduced the transpiration rate of the host plants in light (E₁). The transpiration rate in darkness (E_d) was not influenced in this period and only in the period of formation of necrotic spotsE_d in the host plants was somewhat higher than that in the control plants.E₁ of the host plants gradually reached the level of the control plants in this period. The fungus considerably...

Indole auxins in spinach plants grown in long and short days

Ljubinka Ćulafić, Mirjana Nešković

Biologia plantarum 1974, 16:359-365 | DOI: 10.1007/BF02920998

The endogenous auxin-like substances were analyzed in the shoot extracts of young spinach seedlings, exposed to photoperiodic induction. At least eight indole auxins were found. One of them was identified as tryptophan, the other one is most probably IAA. The plants grown in long days had a higher level of ether soluble auxins than the controls in short days. Separate extractions of plants after each of the eight inductive days showed that the auxin content was not constant, but subjected to irregular oscillations. However, parallel oscillations were also found in control plants grown in short days. Staminate plants were found to contain more endogenous...

Book reviews

Ingrid Tichá

Biologia plantarum 1974, 16:365 | DOI: 10.1007/BF02920999

The interrelation between elongation and IAA-1-¹⁴C metabolism in wheat coleoptile sections

Elwira K. Lis, R. Antoszewski

Biologia plantarum 1974, 16:366-372 | DOI: 10.1007/BF02921000

It has been shown that intensive elongation of wheat coleoptile sections is correlated with indoleacetic acid-1-¹⁴C metabolism. In tissues actively growing the disappearance of indoleacetic acid-1-¹⁴C and formation of conjugates and metabolites (indoleacetamide, indoleacetyl-β-D-glucose, indoleacetyl aspartic acid) is twice as high as in sections where growth has been stopped by physical constraint (plaster) or in tissue which did not elongate by an unknown reason.

Tissue culture cultivation ofLaunaea nudicaulisHook f. infected with a mosaic virus disease

R. Padma, V. S. Verma, Shamsher Singh

Biologia plantarum 1974, 16:373-375 | DOI: 10.1007/BF02921001

Healthy and mosaic infected leaves ofL. nudicaulis have been cultivated onMS and modifiedMS media (MC). Profuse growth and differentiation of tissue have been obtained onMS medium in diseased tissues as compared to the modified medium. It has been found on bioassay that although there is no difference between the concentration of the virus in tissue culture and glasshouse material yet the incubation period of the virus is decreased in tissue cultures.

Book reviews

Ingrid Tichá, Z. Šesták

Biologia plantarum 1974, 16:375 | DOI: 10.1007/BF02921002

Activity of phosphatases and content of free saccharides inN. tabacum ev. 'Samusun' infected by potato virus Y

L. Šindelář, Olga Makovcová

Biologia plantarum 1974, 16:376-381 | DOI: 10.1007/BF02921003

The content of carbohydrates and activities of phosphatases onN. tabacum cv. 'Samsun' inoculated with Y-virus were studied. Dynamic manner of the systematic studies allowed to find new immediate connections. The results of this experiments with the results of our previous investigations gived the explanations of the varying content of carbohydrates in the tissues. The investigated time period of 10 day were divided into 2 parts with breaking point arround fourth day. During the first part at the decreased activity of hexokinases and at the increased activity of phosphatases the accumulation of saccharides in tissues was observed. During the...

Aneuploidy in guava

Shafaat Mohammed

Biologia plantarum 1974, 16:382-388 | DOI: 10.1007/BF02921004

Aneuploids have been identified cytomorphologically in progenies from triploid and diploid-triploid crosses. 30 trisomics, 2 double trisomics, 1 tetrasomic, and 2 higher aneuploids were obtained. Some of the aneuploids were found to be different from those reported earlier and higher aneuploids carried eight extra chromosomes. The plants with one extra chromosome occurred more frequently (67%) than the other aneuploid types.
The changes in morphological traits such as a reduction in the amount of growth and the size of leaf etc. distinguished aneuploids from diploids. In the higher aneuploids the plant parts were highly exaggerated and pollen sterility...

CO₂ and water vapour exchange through adaxial and abaxial surfaces of tobacco leaves of different insertion level

J. Václavík

Biologia plantarum 1974, 16:389-394 | DOI: 10.1007/BF02921005

CO₂ uptake (P _N ) and water vapour efflux (E) through adaxial and abaxial surfaces were measured separately and the corresponding diffusive resistances for water vapour (r₁) were calculated in leaves of different insertion levels during vegetative growth of tobacco plants. Relatively higher values of the abaxialP_N/E ratio in comparison with the adaxial one were found in agreement with relatively higherE_ad/E_ab coefficients and the distribution of the gas exchange in plants in all measurements carried out. Because of the more rapid...

Fogg, G. E., stewart, W. D. P., Fay, P., Walsby, A. E.: The blue-green algae

Jiřina Dvořáková-Hladká

Biologia plantarum 1974, 16:340 | DOI: 10.1007/BF02920994

Grell, K. G.: Protozoology

J. Vávra

Biologia plantarum 1974, 16:400 | DOI: 10.1007/BF02921008

Further natural host plants of a necrotic TMV-strain

Věra Sosnová, Z. Polák

Biologia plantarum 1974, 16:395-396 | DOI: 10.1007/BF02921006

Additional three plant species were found to be natural hosts of a necrotic TMV. strain,Silene inflata SM.,Melandrium albumGarcke andAtriplex nitensSchkuhr.

Substances with cytokinin activity in apple shoots during the vegetative season

A. Friedrich, L. Chvojka

Biologia plantarum 1974, 16:397-399 | DOI: 10.1007/BF02921007

The content of naturally occurring free substances with cytokinin activity was investigated in growing apices of apple shoots during the vegetative period. In the end of May one substance with cytokinin activity was found. During the first period of growth activity we found three such substances with more hydrophobic behaviour and in the culmination of the second period of growth activity we found other three or four substances displaying on the chromatogram more hydrophylic behaviour.