bluuebunny/crossref_metadata_2025 huggingface dataset:
Tb2(bpdc)3 and Eu2(bpdc)3 Nanoparticles (bpdc: 2,2ʹ-Bipyridine-4,4ʹ- dicarboxylate) and Their Luminescence
Authors: Kuzmanoski Ana , Feldmann Claus
Published: February 2014

Tb2(bpdc)3 and Eu2(bpdc)3 nanoparticles (bpdc: 2,2ʹ-bipyridine-4,4ʹ-dicarboxylate) have been prepared via straightforward precipitation from aqueous solution. The nanoparticles exhibit mean diameters of 41(5) nm (Tb2(bpdc)3) and 56(4) nm (Eu2(bpdc)3) and show a very good colloidal stability in aqueous suspension. Particle size and chemical composition have been characterized based on electron microscopy, X-ray diffraction, infrared spectroscopy and thermogravimetry. Photoluminescence validates an efficient excitation of Tb3+/Eu3+ via the bpdc ligand as an antenna that leads to intense characteristic green and red emissions. The absolute quantum yields of Tb2(bpdc)3 and Eu2(bpdc)3 have been determined at 28 and 12%, respectively. Although rare-earth metal-based photoluminescence is typically quenched in water due to vibronic loss processes (v(O-H)), here, the antenna effect and the shielding of the metal centers via the bpdc ligand are very efficient, allowing for an intense green and red emission of the Tb2(bpdc)3 and Eu2(bpdc)3 nanoparticles even in aqueous suspension.
Understanding Persistent Luminescence: Rare-Earth- and Eu2+-doped Sr2MgSi2O7
Authors: Lastusaari Mika , Jungner Högne , Kotlov Aleksei , Laamanen Taneli , Rodrigues Lucas C. V. , Brito Hermi F. , Hölsä Jorma
Published: February 2014

Similar to many other Eu2+,RE3+-co-doped persistent luminescence materials, for Sr2MgSi2O7:Eu2+,RE3+ the initial intensity and duration of persistent luminescence was also found to depend critically on the rare-earth (RE) co-doping. An enhancement of 1 - 2 orders of magnitude in these properties could be obtained by Dy3+ co-doping whereas total quenching of persistent luminescence resulted from the use of Sm3+ and Yb3+. To solve this drastic disparity, the effects of the individual RE3+ ions were studied with thermoluminescence (TL) spectroscopy to derive information about the formation of traps storing the excitation energy. The charge compensation defects were concluded to be the origin of the complex TL glow curve structure. The tuning of the band gap of the Sr2MgSi2O7 host and especially the position of the bottom of the conduction band due to the Eu2+,RE3+ co-doping was measured with the synchrotron radiation vacuum UV (VUV) excitation spectra of the Eu2+ dopant. The model based on the evolution of the band gap energy with RE3+ co-doping was found to explain the intensity and duration of the persistent luminescence.
Comparative studies on the proteins, carbohydrates, acid phosphatase and ribonuclease in caryopses of two orchardgrass (Dactylis glomerata L.) varieties
Authors: Wieczorek Eleonora , Bijak Anna , Morawiecka Bronisława
Published: February 2014

Comparative studies were carried out on some biochemical components in caryopses of two varieties of Dactylis glomerata. The determined protein content depended upon the solvent and amounted to 0.22-0.39 g, with sugar amounting to 2.7-3.6 g and pentoses to 0.30-0.67 g per 100 g of caryopses. The level of pentoses, acid phosphatase and ribonuclease activity was about twice higher in the caryopses of the 'Motycka' variety than that in 'Nakielska'. Similar differences in the two varieties were found in the enzyme activity in the seed and chaff of the Dactylis glomerata caryopses.
Effect of phytohormones on absorption and distribution of ions in salt-stressed bean plants
Authors: Starck Zofia , Kozińska Maria
Published: February 2014

Bean plant seedlings grown in water culture were treated for 5 days either with NaCl or with 7-times concentrated nutrient solution (diminished water potential by 3-103 hPa in both cases). Control and stressed plants were treated for 24 hrs with zeatin and GA,. NaCl-stress reduced distinctly ion absorption rate (K, Ca and P). Zeatin and GA3 promoted potassium uptake, but only in NaCI-treated plants. These hormones diminished Na accumulation in metabolically active organs but increased P- and Ca-content. In plants grown under both kind of stresses zeatin and GA3 partially reestablished the ratio of the main mono- to divalent cations, which increased in the leaves and apical part of the stressed plants. ABA introduced into the nutrient solution caused inhibition of the ion uptake (K, Ca, Mg and P). similar to that caused by NaCl-stress. The above reported results seem to confirm the supposition, that hormones act as an important factor contributing to regulation of both uptake and distribution of ions. In this way growth substances may also participate in the regulation of transport of various substances (among others - assimilates) in the whole plant.
The influence of kinetin on regeneration of the protonema from isolated protoplasts of the moss Funaria hygrometrica L. Sibth
Authors: Nowak Urszula , Młodzianowski Fortunat
Published: February 2014

No stimulating effect of kinetin was noted on formation of the cell wall surrounding isolated protoplasts of the moss Funaria hygrometrica, although kinetin at a concentration of 1µM distinctly accelerated division of cells obtained from protoplasts and stimulated formation of the protonema and gametophores. At higher kinetin concentrations (5 µM) protoplasts, and later cells, increased their volume, whereas regeneration processes took place considerably more slowly than in the control.
Fine structure of plastids during androgenesis in Hordeum vulgare L.
Authors: Młodzianowski Fortunat , Idzikowska Krystyna
Published: February 2014

The fine structure of plastids was studied in the course of androgenesis in in the pollen of Hordeum vulgare L. It was found that these organelles occur in all stages of androgenesis. Their structure was simple and was frequently manifested on the cross section only by the presence of the envelope and matrix of different degree of density. Single thylakoids, nucleoid-like regions and starch grains were, however, also noted. The structure of plastids in embryoids formed from microspores of barley was compared with embryos developed from fertilized egg cell, and we did not found any fundamental differences between them. However, only plastid ribosomes were difficult to identify on ultrathin sections in embryoids and in the embryos.
The effect of nitrogen nutrition on growth and on plant hormones content in Scots pine (Pinus silvestris L.) seedlings grown under light of different intensity
Authors: Michniewicz Marian , Stopińska Jadwiga
Published: February 2014

Pine seedlings were cultivated in the Ingested nutrient solution containing N as NH4Cl at concentrations of 0 and 500 ppm, under a 16-hr day, at a light intensity of 1500 and 500 lx and temperature ± 20°C. Measurements of seedlings and determination of plant hormones were performed 8 weeks after sowing. It was found that more intensive light stimulated initiation of needles and lateral roots as well as elongation of needles and roots, and increased the fresh weight and dry matter of these organs. Growth stimulation of needles was correlated with an increase in free gibberellins, cytokinins, an ABA-like inhibitor and with a decrease in auxins and water content of tissues. A similar effect of light on plant hormones (except ABA) was also observed in roots. The level of this inhibitor depended on N nutrition. Nitrogen bad a similar effect as light on the growth and initiation of needles and lateral roots. However, it strongly inhibited elongation of roots and increased the water content of the tissues. In needles N increased the level of GAs and auxins, under both light variants, as well as the level of cytokinins, under more intensive light. It decreased the amount of ABA-like inhibitor. In roots the effect of N nutrition on the level of plant hormones depended upon the light intensity. Under light of low intensity N decreased the level of GAs and ABA, increased the level of auxins and had nonsignificant influence on the level of cytokinins. Under more intensive light it had no effect on the GAs and auxin levels and increased the level of cytoikinins and the ABA-like inhibitor.
Reduction of nitrates in Cucumis sativus L. seedlings I. Influence of tungsten and vanadium on absorption and reduction of nitrates
Authors: Buczek Józef , Kowalińska Ewa , Kuczera Krystyna
Published: February 2014

Investigations were conducted on the influence of tungsten (Na2WO4) and meta-vanadate (NaVO3) on uptake and reduction of nitrates by cucumber seedlings. Tungsten and vanadium almost completely inhibited nitrate reductase activity (NR) after treating the plants for 24 hours with nitrates in the presence of 10-4 M WO4-2 and 10-3 M VO3-. Uptake of NO3- in the presence of WO4-2 in this same period of time was lowered by about 50 %, while in the presence of VO3- by seventy percent. The ratio of NO3- absorbed to that reducted in control plants was around 3, whereas in the presence of WO4-2 and VO3- 9 and 8 respectively. The effect of NR inhibiting activity by WO4-2 and VO3- was significant but somewhat weaker if both inhibitors were applied to the plants 24 hours after formation of the NR system, whereas NO3- uptake was subject to a slight lowering. The above data suggest that WO4-2 and VO3- after a 24 hour application of these inhibitors to plants, primary inhibit biosynthesis and activity of NR and to a lesser extent effect NO3- absorption. On the basis of results reached the Butz and Jackson (1977) hypothesis concerning the model of NO3- uptake and reduction by plant tissues is discussed.
Accumulation of heavy metals in an ecosystem influenced by zinc-plant emissions
Authors: Czuchajowska Zuzanna , Lorek Elżbieta , Strączek Teresa
Published: February 2014

Accumulation of Pb, Zn, Cd, Mn, Fe and Mg reaching the selected ecosystem in the dust emitted by a zinc-mill, was estimated in the leaves of Pinus silvestris, Vaccinium myrtillus and Vaccinium vitis-idaea, the main plant components of the system, and in the five upper soil layers. The values of metal concentration were different for the three considered species and showed-for each of them - dependence on the pollution degree of the stand. This regularity concerned Pb, Zn, Cd and Mn but not Fe and Mg. A significant positive correlation exists between the content of Pb, Zn and Cd in the soil and their concentration in leaves, the correlation for Mil is significant but negative. Manganese in leaves proved to be an antagonist in respect to the other metals.
Influence of cyclophosphamide on respiration and membrane permeability of plant cells
Authors: Podbielkowska Maria , Zobel Alicja , Wałęza Maria
Published: February 2014

A specific influence of cyclophosphamide, an oncostatic drug of the group of alkylating agents, has been demonstrated on cellular respiration and the permeability of cell membranes. The tested drug under the experimental conditions inhibites cell respiration by about 20-30 per cent as compared with the control. The permeability of the plasmalemma and tonoplast de-creased markedly under the action of cyclophosphamide.
Result of cyclophosphamide effect on meristematic cells of anaerobic respiration
Authors: Podbielkowska Maria , Wałęza Maria
Published: February 2014

Hypertrophy of rough ER under the influence of cyclophosphamide (oncostatic substance) in meristematic cells of normal and modified glycolysis pathways has been demonstrated. The organization of ergastoplasmic structures has been considered as a process of adaptation to the changed energy conditions caused by cyclophosphamide since analogous changes in protoplastic structures have been found in meristematic cells of oxygen respiration.
Ribonucleic acids in the embryos of germinating wheat grains of different ripeness
Authors: Weidner Stanisław , Kulka Krzysztof
Published: February 2014

During 48 h germination of wheat grains of different ripeness the amount of RNA in the germinating embryos doubles, while the rate of synthesis is to a large extent correlated with the level of ribonucleic acids accumulated during the development and ripening of the grain. The highest RNA content was noted in the germs developing from grain harvested at the stage of full ripeness, the lowest - in germs from grain at milk ripeness. Intensity of 3H-uridine incorporation into the RNA fraction of the germs during 24-h germination also depends on ripeness. Significantly lower RNA synthesis was noted in germinating embryos from wheat grain harvested during milk ripeness as compared to wax or full ripeness.
Effect of gibberellic acid on the formation and development of antheridia and oogonia in Chara vulgaris L.
Authors: Godlewski Mirosław , Kwiatkowska Maria
Published: February 2014

The experiments were performed on Chara vulgaris thalli cultivated in axenic conditions. It has been found that application of GA3 at concentrations of 10-9 -10-4 M has no effect on the numbers of developing antheridia and oogonia. GA3 stimulates the gemmation of capitular cells thus increasing the number of filaments in antheridia (by 45% when 10-8 M is used). The number of mitotic cycles preceding the differentiation of spermatozoids is not significantly modified by this gibberellin. The number of spermatozoids in antheridia increases by about 20% when 10-8 -10-6 M GA3 concentrations are used. GA3 shortens the duration of spermatogenesis (by 2.5 days, at 10-7 M concentration). This effect is due to a shortening of the mitotic cycles in filaments. On the other hand, the time of spermatozoid differentiation, which in the control material lasts about 5.3 days, is not changed significantly by GA3. GA3 hastens the maturation of oogonia and the formation of oospores - both effects are proportional to the GA3 concentration used.
The growth-retarding effect of daminozide in Spirodela oligorrhiza (Kurz) Hegelm., and its reversal by gibberellin
Authors: Janas Krystyna M.
Published: February 2014

Butanedioic acid mono-(2,2 dimethylhydrazide) (daminozide), in a concentration of 10-3 M retarded growth of Spirodela oligorrhiza and increased chlorophyll and protein content in the fronds. Gibberellin A3 and benzylaminopurine partially alleviated the symptoms of daminozide action.
Messenger RNas : their utilization and degradation during pollen germination and tube growth
Authors: Mascarenhas Joseph P. , Mermelstein Joann
Published: February 2014

During pollen germination and tube growth at least 230 new proteins are synthesized, as determined by 35S-methionime labeling and two dimensional gel electrophoretic analysis of the labeled proteins. The same number and pattern of protein spots is seen whether or not actinomycin D is included in the, medium, indicating that the mRNAs present in the unger-minated pollen grain and those newly synthesized code for the same proteins. The genetic program during at least the latter part of pollen maturation prior to anthesis and that during pollen germination and tube growth thus appears to be similar if not identical. During the first hour of pollen tube growth about 500/0 of the protein synthesis that occurs utilizes previously synthesized mRNAs. The remaining 50% occurs on newly made mRNAs. The ungerminated mature pollen grain contains 196 pg of RNA and approximately 6 X 106 molecules of poly(A)+ RNA, i.e. mRNAs. The rate of protein synthesis corrected for internal pool changes in the labeled amino acid used (3H-leucine) is highest during the first 15 min of pollen tube growth. The rate decreases rapidly thereafter for the next 45 min. Concurrent with the reduction in rate of protein synthesis there is a reduction in the poly(A) content of the pollen RNA and in the amount of poly(A) per pollen, grain. The total RNA per pollen grain, however, appears not to change during this period.
Polysaccharides and lipids in microsporocytes and tapetum of Rhoeo discolor Hance. Cytochemical study
Authors: Albertini Louis , Grenet-Auberger Helene , Souvre Andre
Published: February 2014

The present report, which mainly presents cytochemical results, establishes the determination, localisation and evolution of the cytoplasmic and wall polysaccharides and lipids in the microsporocytes and the plasmodial tape turn of Rhoeo discolor Hance. Enzymatic controls, use of autoradiographic methods, and electron microscopy, have proved the validity of our cytochemical results and permitted to precise these results. In the microsporocytes and pollen grains, the callosic special wall, the carotenoid exine, the pectocellulosic cellulasic in tine, and the callosic and pectic young curved wail. between the generative cell and the vegetative cell, have mainly held our attention. As for the tapetum which remains poor in insoluble polysacharides till the ultimate stages of microsporogenesis, it grows richer in choline - phospholipids during meiosis and, more lightly, in carotenoids beyond the tetrad stage; the periplasmodium does not seem to participate directly in the increase of exine lipids.
IAA-peroxidase relation in the microsporocytes and anther wall during successive stages of meiosis in Larix europaea L.
Authors: Górska-Brylass Alicja , Chwirot Wiesława B. , Michalski Leszek
Published: February 2014

During anther meiosis in Larix europaea considerable variations in the level of peroxidase activity and endogenous auxin content occur both in the microsporocytes and in the anther wall. However, the IAA-peroxidase relations are different in each of these two parts of the anther. In the anther wall characterized by the occurrence of anodic isoperoxidases, the changes in peroxidae activity show a positive correlation with those in endogenous auxin content. In the microsporocytes containing almost only cathodic asoperoxidases the levels of endogenous auxin content and peroxidase activity show a reverse correlation. Thus a preponderance of isoperoxidases showing IAA-oxidase properties occur only in the microsporocytes. These results suggest the important role of the IAA=peroxidase system in the mechanism of differentiation of cells undergoing anther meiosis.
The function of the tapetal tissue during microsporogenesis in Lilium
Authors: Reznickova S. , Willemse M. T.
Published: February 2014

The main functional activity -of the tapetum in the Lilium anther is the synthesis of reserve lipids and carotenoid pigments. The fusion of these substances during tapetum desintegration results in the formation of pollenkitt Pollernkitt participates in the formation both of the exine and of sporopollenin-containing structures of the tapetal cell (orbicules, tapetal and peritapetal membranes) during the last steps of anther development.
Formation and development of sperms in angiosperms
Authors: Tatintseva S.
Published: February 2014

Spermiogelnesis has been studied in a large number of Angiosperm species characterizing different levels of phylogenetic system. The formation and development of male gamets can be described as formation of sperm cells that undergo ontogenesis which stimulates changes up to full maturity of the pollen grain. The process of ontogenesis is aimed at creating a suitable delivery system by the pollen tube to a female gamete.
Ultrastructural changes during megasporogenesis in Epipactis (Orchidaceae)
Authors: Bednara Józef , Kuraś Mieczysław , Rodkiewicz Bohdan
Published: February 2014

Plastids were temporarily localized within the micropylar portion of the early first prophase Epipactis meiocyte. Some of these plastids were observed in close proximity to the nuclear envelope. With the exception of this short period plastids were distributed randomly in the meiocyte. During late prophase, starch-containing plastids become cup-shaped and depleted of starch. Plastids were found within both dyad cells and all cells of the tetrad. Elongated segments of ER cisternae in various configurations were present. The chalazal wall of the prophase meiocyte differed from other walls in the presence of the ingrowths and plasmodesmata. The micropylar portion of the nuclear envelope at some stages of the I prophase seemed to be devoid of pores whereas the chalazal part contained numerous pores. These structural characters reflect a polar differentiation of the meiocyte along a micropylar-chalazal axis.
Intercellular relations and wall structures in mature embryo sacs of four species of angiosperms
Authors: Fougére-Rifot Monique
Published: February 2014

During the maturation process of an ovule, the internal walls of the embryo sac becomes gradually thinner from the poles to the central cell. The thinning process results in an association of two plasma membranes with no polysaccharide structure betwen them. The presence of one disymmetrical ER cistern along the walls during the thinning process permits to anticipate a turn-over of carbohydrates.
Ultrastructural organization of the tomato embryo sac at the time of fertilization
Authors: Kadej Franciszek , Kadej Agnieszka
Published: February 2014

In tomato embryo sac at the time of fertilization noticeable multiplication of the endosperm cytoplasm is observed. The cytoplasm of the egg cell, next to the nucleus, appears loose with distinct mitochondria and plastids. At a distance from the nucleus ribosomes become grouped into a cytoplasmic mass of great uniformity. Nucleolar structure of the egg cell nucleus displaces to its periphery. Its new position seems to he related to the process of fertilization. In the area of the endosperm two nuclei in close contact to each other are found which suggests the beginning of secondary fertilization.
Endopolyploidy in the antipodals of Ranunculus subgenus Ba trachium
Authors: Turała-Szybowska Krystyna , Wędzony Maria
Published: February 2014

In three species of Ranunculus subgenus Batrachium, viz. Ranunculus peltatus Schrank., R. penicillatus (Dumort.) Bab. and R. baudotii Godr., differentiation of antipodals is connected with endomitotic polyploidisation. Calculations of nuclei volume and analysis of nuclei structure were performed in successive developmental stages. Nuclei of the antipodals attained different levels of endopolyploidy: 32n (R. penicillatus), 64n (R. peltatus) and 1024n (R. baudotii), as a maximum. In R. peltaius and R. baudotii, which reproduce sexually, the stimulating effect of fertilization on endomitotic polyploidisatian of the antipodals was found. The occurrence of giant chromosomes in highly endapolyploid nuclei of the antipodals in R. peltatus and baudotii was noted.
Relation of the male gametes with embryo sec cells. The hypothesis of double fertilization
Authors: Belayeva N. S.
Published: February 2014

The sperms one after another get out of synergids. The front sperm gets the first into the egg cell attraction zone and then the sperm comes into contact with egg membrane. At this moment Attraction ceases and the second sperm is led by a current of cytoplasma to the central nucleus. In the egg cell the sperm nucleus is led to the nucleus by cytoplasmic current too. After fertilization the character of cytoplasmic motion changes, because of a cell membrane damage. The presence of the sperm in the female nuclei may also serve as a regulating factor.
Structural relationships among central cell and egg apparatus cells of barley as related to transmission of male gametes
Authors: Cass David D.
Published: February 2014

Barley embryo sacs were examined using light and electron microscopy before and during fertilization. One synergid degenerates after pollination with loss of nuclear and cytoplasmic organization and cell wall material between synergid and central cell. Some wall between egg and central cell is also lost. After pollen tube discharge into the degenerate synergid, the male gametes leave the synergid entering a pocket of central cell cytoplasm separated from the synergid only by membranes. This could provide for efficient gamete transmission and possible recognition through specific membrane contacts.
Nucellar and integumentary embryony in angiosperms
Authors: Naumova T. N.
Published: February 2014

The form of adventive embryony is determined by the type of ovule. Nucellar embryony is possible in crassinnucellate ovules, and integumentary embryony in tenuinucellate ovules.
Note on apomixis in ferns
Authors: Tilquin J. P.
Published: February 2014

In 1964, two new types of apogamy were described in ferns. The sporangia contain at the starting-point 16 spore mother cells and at the endingpoint 32 diplospores. On the one hand, the meiosis is replaced by a mitosis, on the other hand, the first meiotic division aborts and the restituition nucleus divides mitotically. The author's observations imply that the second process is a variant of the first one.
Biochemical changes in embryos of dormant and after-ripened seeds of Caryophyllaceae
Authors: Köhler Karl-Hermann , Hecker Michael
Published: February 2014

The dependence of 14C-leucine, 3H-uracil and 3H-thymidine incorporation in dormat and after-ripened seeds is demonstrated and discussed together with other metabolic events. Striking differences in dependence on the physiological state in both types of seeds could only be found in the axes of after-ripened seeds.
Chlorophyll content and culture of flax embryos in vitro
Authors: Petrova A. , Ciamporova M. , Erdelska O.
Published: February 2014

During in vitro cultivation of green flax embryos excised 14 days after fertilization on White's medium the chloraphylls a and b are gradually destroyed and the lamellar system of plastids is disintegrated. It was possible, to prolong somewhat the presence of chlorophyll and to enhance embryo growth by culture in the dark and by adding kinetin. Light has a stimulating effect on the germination of embryos. Streptomycin inhibits chlorophyll synthesis not earlier than at germination. Young, green embryos are unable to sumvive and develop on media without sucrose. It is supposed that photosynthesis does not occur in flax embryos in vitro, and that green embryos are not more autotrophic in vitro than those of leucoembryophytes.
Embryological features of some Piperales
Authors: Nikiticheva Z. I.
Published: February 2014

Embryological investigation of some Piperales (Piperaceae and Saururaceae) as well as analysis of the available data confirm the ancient origin and natural character of this order. Similarity of the seed structure and a great variety of modes of formation of the embryo sac, endosperm and embryo are found in Piperales.
Evolution of sexual structures in higher plants (main types of meiosis)
Authors: Yakovlev M. S.
Published: February 2014

A new conception of evolutionary development of sexual structures in Magnaliophyta is presented. This group has no gametophyte phase. Their gametes differentiate in the following pattern: somacyte - meiocyte - gametocyte - gamete.
Mitochondria during androgenesis in Hordeum vulgare
Authors: Idzikowska Krystyna
Published: February 2014

Different number of mitochondria of varying structure was observed in particular stages of the development of barley (Hordeum vulgare) microspores, stimulated by the in vitro culture to form embryoids. This variability was reflected in different shape of sections, different ratio between total area of mitochondria profiles and area of cytoplasm sections, varying number of cristae, and different density of the matrix. Within the cristae of some mitochondria crystalline inclusions were observed. Mitochondria divided by a contraction. In the matrix of some mitochondria spheric bodies were formed. They were surrounded by one or two membranes. It is suggested that the bi-membrane forms constituted promitochandria, whereas unimembrane forms could constitute promicrobodies.
"Carpelloid stamens" in Lotus sp.
Authors: Wojciechowska Wanda
Published: February 2014

The anatomy and cytology of flower buds in which one or two stamens underwent modifications of various degree, termed in the teratological terminology "carpelloid stamens" were analysed in Lotus. It is presumed that these disturbances were due to the hybrid character of the studied plants.
Development and structure of hawthorn seeds (Crataegus L.) from species occurring in Poland
Authors: Pelc Stanisław , Ptak Krystyna
Published: February 2014

The development, internal and external structure of seeds of Crataegus monogyna Jacq., C. curvisepala Lindm., C. lindmannii Hrabĕt-Uhr., C. oxyacantha L. em. Jacq., C. palmstruchii Lindm., C. macrocarpa Hegetsch were investigated. It was found that the embryo development is specific, and the development of endosperm precedes that of the embryo. In mature seeds of the examined species endosperm is present under the seed coat and the embryo with large cotyledones and radicle is completely immersed in it. The external appearance of the seeds of particular species differs, and on this basis their specific appurtenance may be determined.
A species concept in the genus Pleurocladula (Hepaticae)
Authors: Krzakowa Maria , Szweykowski Jerzy
Published: February 2014

On the basis of comparative cultures, biometric studies, variability of isozymes and phenolic compounds, the authors come to conclusion that two genetically different taxa are in evidence.
The map of potential natural vegetation as a basis for comparative studies and geobotanical regionalization
Authors: Plit Joanna
Published: February 2014

A method of typology and regionalization of landscape units of vegetation on the basis of a map of potential natural vegetation is presented. Particular attention has been paid to the methodical basis of the conducted division. The map of potential natural vegetation was subsequently compared with maps of other elements of the natural environment and the result of geobotanical botanical regionalization was compared to the complex physicogeographical regionalization.
Nonparallelism of cambium cells in neighboring rows
Authors: Włoch Wiesław
Published: February 2014

The periclinal walls of cambial cells in neighboring lineages (rows) may not be parallel when viewed in their radial aspect. This lack of longitudinal parallelism may be so extensive that in active cambium pairs of cells from neighboring rows may be in contact only along restricted segments. This means that the initial cells, rather than farming a continuous layer, may be arranged in an irregular network pattern from which some parts project inward or outward from the layer of their mutual cantacts. The longitudinal nonparallelism of cambial cells becomes more pronounced during symplasitic radial growth. Unequal periclinal divisions counteract this, and in initial cells abscission of the parts projecting from the layer of mutual contact occurs. When the cambium passes from a period of activity to a Period of rest a continuous layer of initials is reestabhshed. This involves elongation by intrusive growth of those cells previously shortened as the result of irregular periclinal divisions. The division walls in cambial cells may be warped, that is they change their orientation along the longitudinal direction perhaps even similar to an aircraft propeller. A division wall may thus be periclinal in one part of the cell and anticlinal in another.
Generative reproduction of Vaccinium myrtillus in laboratory conditions and the influence of zinc-smelter emissions on it
Authors: Czuchajowska Zuzanna , Strączek Teresa
Published: February 2014

The germination of Vaccinium myrtillus seeds and the development of the seedlings in laboratory conditions are described. The dynamics, the power of germinaltion and Pieper coefficients for the seeds were strongly influenced by the intensity of zinc-,smelter pollution of the forest stand from which they originated. The rates of survival were also estimated for seedlings transferred from filter-;paper into polluted and unpolluted samples of soil and litter. The differences noticed in the latter parameter point to the possibility of formation in the polluted stand of ecotypes more resistant to the influence of pollution than the original ones.
Specific effects of certain salts on the growth of roots of young corn seedlings
Authors: Hatata Mohammed , Farah Michel
Published: February 2014

The effect of different concentrations of NaCl, Na2SO4, MgCl2 and MgSO4 on the growth in length of the first seminal root of corn, and on the change in dry weight of the whole seedling and its separate parts have been studied. The effect of mannitol was also investigated for comparison and to study the osmotic effect. The effect of salts on root growth was dependent on the salt species; all effects were specific for the ions investigated, not due to osmotic activity of the solution. The growth of corn roots was suppressed by concentrations of salts much lower than those required to suppress germination. All solutions tested from 1 to 20 meq/l inhibited growth of the root; the retardation increased with increase of concentration. The effect of salts on growth of corn roots was due to both cations and anions and the effect of sodium was stronger than that of magnesium and chloride was more effects than sulphate.
Attempts to induce haploids in anther cultures of sugar, fodder and wild species of beet
Authors: Rogozińska Janina , Gośka Maria
Published: February 2014

In the present investigation, aimed at obtaining beet haploids from anthers, the effect of mineral media, potato and sugar beet extract and p-fluorophenylalanine (PFP) in combination with growth substances was tested. Nutrient-starved plants as anther-donors, anther-starvation, cold treatment and photoperiod were also analysed. On all mineral media the anthers produced callus and roots; however, the percentage depended on the combination of growth substances used. The best medium for differentiation was that of Linsmaier and Skoog with 25 µM zeatin or 6-(3-methyl-2-butenylamino)purine with 5 µM naphthalene-l-acetic acid (25.5%). The addition of PFP caused an increase in the percentage of anther differentiation (41.6%). Besides callus and roots on one of the anthers (in ca. 140000 tested), vegetative buds were formed from which numerous plants were obtained (2n). Plant and anther nutrient starvation did not improve the anther response to differentiation, nor did it induce haploid development, similarly as cold treatment of inflorescences or isolated anthers. The anthers of wild species showed lower ability to differentiate than those of sugar or fodder beets. Cytological analyses showed formation of multicellular structures until ca. the 12-th day of anther culture; afterwards, they degenerated.
Pollen dimorphism and androgenesis in Hordeum vulgare
Authors: Idzikowska Krystyna , Ponitka Aleksandra , Młodzianowski Fortnat
Published: February 2014

Dimorphism of binucleate pollen grains of Hordeum vulgare has been confirmed. It is considered, however, in contrast to the accepted opinions, that some of the large pollen grains with dense cytoplasm lying close to the tapetum are the outset forms for embryoids, and not the small pollen grains with scarce cytoplasm lying in the pollen sac centre.
Structural and functional polymorphism of plastids in leaves of Clivia miniata Rgl. II. Ontogenesis of plastids in mesophyll cells and in cells surrounding vascular bundles
Authors: Mikulska Eugienia , Damsz Barbara , Żołnierowicz Halina
Published: February 2014

In mesophyll cells and in cells adjoining vascular bundles of leaves in Clivia miniata Rgl. there occur chloroplasts differing with respect to their structure and the type of accumulated substances. Chloroplasts of mesophyll cells have a well-developed system of grana and intergrana thylakoids; within the stroma they accumulate solely inclusions of lipid character. Chloroplasts of cells surrounding the bundles are smaller than chloroplasts of mesophyll cells, have a poorly developed system of inner membranes and are able to accumulate only considerable amounts of starch. The third type of chloroplasts occurs in parenchymateous cells of the vascular part of the bundles. These chloroplasts, much smaller than those described above, have a reduced system of inner membranes and are not capable of accumulating either starch or lipid droplets. In stroma, they contain only plastoglobules. It seems probable that morphologically uniform proplastids are the precursors of all the studied types of chloroplasts. Their developmental sequence is determined by the degree of cellular differentiation, the type of cell as well as by the function it performs.
Apical control of xylem formation in the pine stem. II. Responses of differentiating tracheids
Authors: Porandowski Jarosław , Rakowski Krzysztof , Wodzicki Tomasz J.
Published: February 2014

The effect of auxin supplied to the main stem of 5-year-old Pinus silvestris trees during various periods after decapitation upon differentiation of the secondary xylem tracheids was investigated. The results revealed the complexity of auxin involvement in the regulatory system of tracheid differentiation of secondary xylem. It is manifested both as the inductive effect to which the cells respond in the meristematic phase and in the continuous control during the consecutive stages of radial growth and maturation. A lack of auxin during the meristematic phase resulted in smaller cell diameters and reduced the daily rate of cell wall deposition even though these cells progressively grew and matured in the presence of auxin. The intensity of these two processes increased and the cells deposited thicker walls when auxin was supplied during all stages of tracheid differentiation even though the period of maturation decreased. Under these conditions tracheids of compression wood type differentiated. Continuous availability of auxin causes earlier termination of tracheid maturation while lack of auxin results in a delay of autolysis of protoplasts. In this case auxin probably functions in a system specifying information concerning the position of the cells in respect to the cambial layer.
Abscisic acid as a factor in regulation of photosynthetic carbon metabolism of pea seedlings
Authors: Faltynowicz Maria , Lechowicz Waldemar , Poskuta Jerzy
Published: February 2014

The influence of abscisic acid (ABA) on carbon metabolism and the activity of ribulosebisphosphate (RuBP) and phosphoenolpyruvate (PEP) carboxylases in 8-day-old pea seedlings was investigated. It was endeavoured to correlate the changes observed in metabolic processes with the endogenous ABA level. In plants treated with ABA incorporation of labeled carbon into sucrose, glucose, fructose and sugar phosphates was depressed, while 14C incorporation into starch, ribulose and malic acid was enhanced. The activity of RuBP carboxylase was considerably lowered, whereas that of PEP carboxylase was slightly increased. It is considered that inhibition of photosynthesis due to the action of ABA is caused to a great extent by the obstruction of the C-3 pathway and reduced activity of RuBP carboxylase, whereas (β-carboxylation was not blocked.
The effect of chromate on the synthesis of plastid pigments and lipoquinones in Zea mays L. seedlings
Authors: Krupa Zbigniew , Ruszkowski Marek , Gilowska-Jung Ewa
Published: February 2014

Maize plants cultivated on nutrient solutions containing increasing amounts of CrO42- (from 10-7 to 10-4 M) showed growth inhibition, strong reduction of the root system and an increase of dry matter of leaves. The highest accumulation of chromium in plant organs appeared in the roots. Chromate taken up into leaves caused changes in the content of plastid pigments and lipoquinones similar, in general, to those in senescent plants.
Changes in ribosomal proteins of wheat embryos during accelerated ageing of the grain
Authors: Zalewski Kazimierz , Weidner Stanisław
Published: February 2014

Electrophoretic separation of ribosomal proteins of wheat embryos from grain analysed immediately after the harvest (control) yielded four anodic and six cathodic fractions. In caryopses subjected to accelerated ageing the ribosomal proteins separated into 5 anodic and 8 cathodic fractions. With the advance of ageing an increase in the amount of low molecular weight molecules was observed in the ribosomes of the embryos. In ribosomes from wheat caryopse embryos (control) 76 individual proteins - 10 acidic and 66 basic ones - were recorded. In the embryos of aged caryopses 53 proteins were found - 16 acidic and 37 basic ones. The mobility of nearly all individual proteins was also changed as compared to that in the control sample. This is additional evidence of the modification of the proteins in the ageing process and leads as consequence to a change in their electric charges.
Rape embryogenesis. IV. Appearance and disappearance of starch during embryo development
Authors: Tykarska Teresa
Published: February 2014

Starch appears first in the suspensor of the proembryo with two-cell apical part. It is observed in the embryo proper from the octant stage. At first it is visible in all the embryo cells in the form of minute transient grains which disappear during cell divisions. But the columella mother cells and their derivatives have persistent large grains. When the embryo turns green in the heart stage a gradual accumulation of storage starch begins and lasts to the end of embryogenesis. Storage starch grains appear first in the auter cortex layers of the hypocotyl where the largest grains are to be found later, and afterwards in all the other tissues. Starch is usually absent in the frequently dividing cells, but even there it appears in the form of minute grains after the end of cell divisions. Disappearance of starch starts when the intensive green colour of the seed coat begins to fade. The first to disappear are the smallest granules in the regions where they were noted latest. In the embryo axis the starch grains remain deposited longest in dermatogen and cortex cells in the lower hypocotyl part. They are visible there, still when the seed turns brown. In black seeds starch may be only found in the columella the cells of which throughout embryogenesis contain amyloplasts filled with starch. These grains disappear completely at the time when the seeds become dry.
Flavonoids in the leaves of Polish species of the genus Betula L. IV. The flavonoids of Betula pubescens Ehrh., B. carpatica Waldst., B. tortuosa Ledeb., and B. nana L. leaves
Authors: Pawłowska Lucyna
Published: February 2014

Besides the flavonoids detected earlier, the leaves of purebred B. pubescens specimens were found to contain quercetin 3-arabinoside, isorhamnetin 3-galactoside, luteolin 4'-glucoside, isoquercitrin, acacetin 7-glucoside, and perhaps scutellarein 7-glycoside, whereas B. nana exhibited a low content of myricetin 3-galactoside and quercetin 3-arabinoside, and also possibly quercetin 7-rhamnoside. The qualitative composition of the flavonoids of desiccated B. tortuosa leaves seems to point to the validity of the assumption that this birch is of hybrid origin. The set of flavonoids in B. carpatica was almost identical with that in B. tortuosa.
Flavonoids in the leaves of Polish species of the genus Betula L. V. The taxonomic position on the basis of flavonoid composition
Authors: Pawłowska Lucyna
Published: February 2014

A comparison of the qualitative composition of leaves from specimens of Polish taxa of the genus Betula L. points to a specific distinction of B. pendula Roth., B. pubescens Ehrh., B. humilis Schrk., B. nana L., and B. oycoviensis Bess., and also B. "nova" which requires description according to the International Code of Botanical Nomenclature. B. obscura Kot. can be recognized only as a subspecies of B. pendula, whereas B. carpatica Waldst. and B. tortuosa Ledeb. may be geographical variaties of one and the same subspecies distinguished within B. pubescens.
The development rhythm of the flower-bud in some Papilionaceae species. III. Macrosporogenesis, microsporogenesis and early gametogenesis in several species of the Vicieae tribe
Authors: Wojciechowska Wanda
Published: February 2014

Each of the examined species of the tribe Vicieae (Vicia faba, V. sativa, V, villosa, Lathyrus silvester, L. pratensis and Pisum sativum) has its peculiar characteristic development rhythm of the bud. A similarity has been demonstrated between the development rhythms of flower buds of Vicia faba and Pisum sativum. It was found that mature flowers of autogamous species had long calyces, whereas those of the allogamous species were short as compared with the petals of the corolla.
Imbibition and germination in the seeds of Heliotropium supinum L.
Authors: Bhatia Ramesh C.
Published: February 2014

Imbibition in the seeds of Heliotropium supinum L. varies under different temperatures. The optimum temperatures for imbibition and germination are also different. For germination 39% imbibition is essential, and this capability is achieved by 12-week-old seeds. With duration of dry storage imbibition increases. The imbibition and germination percentages decline on re-dry storage of seeds after embeding in mud. A soil moisture of 44% is optimal for germination. A correlation exists between imbibition and germination.
Autoradiographic analysis of the effect of cytokinin on protein and RNA syntheses in the Ceratodon purpureus protonema
Authors: Woźny Adam , Nowak Urszula , Szweykowska Alicja
Published: February 2014

In the protonema of Ceratodon purpureus (Hedw.) Brid., apical parts of the protonemal filaments (apical cells, initials of protonemal side branches and of gametophore buds) proved to be preferential sites of [14C]-leucine incorporation into proteins. In some filaments, a similar preference for [3H]-uridine incorporation into RNA was observed, whereas in others there was a rather uniform distribution of label over all cells. A short (0.5-2 h) treatment with cytokinin (N6-2-isopentenyladenine) enhanced [14C]-leucine incorporation, without changing the relative distribution of label. No such enhancement, as well as no change in label distribution could be observed in [3H]-uridine incorporation. No direct relationship seems to exist between the early promotion of protein synthesis by cytokinin in the protonema and cytokinin induction of gametophore buds.
The formation of polyribosomes during the germination of grains of wheat of different ripeness
Authors: Weidner Stanisław
Published: February 2014

The total ribosomal fraction was isolated from whole seedlings from grains of wheat gathered at the milk-, milk-wax and full-ripeness stages. A gradual increase in the amount of the total ribosomal fraction was observed during germination until the 6th day in all of the studied groups. From the 6th to 12th days of germination a decrease in this, fraction was found. In all of these groups polysomes constituted 88-90% of the total ribosomal fraction after 48 hrs of germination. From the 2nd to the 12th day, polysomes made up a decreasing percentage of the total ribosomal fraction. The percentage of polysomes contained in this fraction at the begining (0-24 h) as well as at the end (10-12th day) of the studied period of germination of immature grains was lower than in mature ones, which is synonymous with a lower level of protein synthesis in their tissues. When the results were calculated per seedling, it was shown that the less mature the grain, the lower the total ribosome content. These results show that grains gathered at full ripeness are the most vigorous.
Influence of aluminium chloride and sulphate on the root meristem of Vicia faba L.
Authors: Wojciechowska Barbara , Kocik Halina
Published: February 2014

The influence of various (0.1, 0.05, 0.01, 0.001 and 0.0001 M) aluminium chloride and aluminium sulphate concentrations on the mitotic activity of the root meristem of the bean Vicia faba L. was investigated after 24 h of incubation. A mito-depressive action of the tested compounds, irreversible at higher concentrations was observed. The tested substances induced chromosome aberrations (fragmentation and bridges in anaphase or telophase, micronuclei, binuclear cells) and inhibited elongation of roots. The results of topochemical analysis are described.
Chromosome numbers of Polish vascular plants (Part 4)
Authors: Mizianty Marta , Mirek Zbigniew , Frey Ludwik
Published: February 2014

The authors give results of karyological studies carried out on 20 species of vascular plants from Poland. Most of the results are reported for the first time for this country. The chromosome number of Gnaphalium hoppeanum 2n=28 was established for the first time.