The presence of antimicrobials in root, hypocotyl and cotyledon homogenates of Norway spruce was studied using in vitro assays with soil-borne pathogens. For the studies presented here Norway spruce (Picea abies (L.) Karst.) as a typical host and forest tree and Pythium as a typical soil-borne pathogen were used. The highly virulent species Pythium ultimum and the less virulent species Pythium irregulare were chosen for all experiments. They are both the causal agents of damping-off disease, which can affect plants at a very early stage. The strongest antimicrobial effect was observed using medium prepared from older seedlings and containing extracts from cotyledons. The influence of various treatments on antimicrobials accumulation in spruce extracts was also tested. Seed coat shedding was observed to affect mortality of Picea abies seedlings infected by Pythium. Seedlings which had shed their seed coats were more resistant to Pythium attack. This phenomenon could be correlated with antimicrobial production in well developed cotyledons.
Autafluarescence of the pollen wall of Lilium shows a correlative change with its development. When the pollen of Gasteria is injected into the anther of Lilium, it exhibits almost the same characteristics of wall autofluorescence as those of Lilium. Only the last stages of wall development are dissimilar. During this period the pollenkitt sticks to the pollen wall in Lilium only. The conclusion is that in the exine of Gasteria pollen, in contact with the locular fluid of Lilium, polymerization of Lilium sporapollenin occurs instead of a structural addition to the wall. This polymerization is a continuous process during the entire development.
The egg apparatus of Spinacia was studied from the time the embryo sac reaches its maximal size to just before fertilization, i.e., until about 8-9 hours after pollination. At maturity each synergid has a large elongated nucleus and prominent chalazal vacuoles, Numerous mitochondria, plastids, dictyosomes, free ribosomes, rough endoplasmic reticulum (RER), and lipid bodies are present. The cell wall exists only around the micropylar half of the synergids and each cell has a distinct, striated filiform apparatus. In general, degeneration of one synergid starts after pollination. The egg cell has a spherical nucleus and nucleolus and a large micropylar vacuole. Numerous mitochondria, some plastids with starch grains, dictyosomes, free ribosomes, and HER are present. A continuous cell wall is absent around the chalazal end of the egg cell.
The cellularization of the endosperm of Brassica napus was investigated with light microscopy after embedment in Technovit 7100. The microtubular cytoskeleton was visualized by immunofluorescence techniques after embedment in butyl methyl metacrylate (BMM). The analyses of sectioned seeds, sampled at various developmental stages, revealed that the endosperm has a nuclear phase up to the early heart shaped stage of the embryo. From the heart shaped stage onwards cells and alveoli are formed in the endosperm. The cellularization of endosperm was preceded by alveolus formation except in the region surrounding the embryo suspensor and in the chalazal zone of the embryo sac where the nuclear endosperm vacuolated and cell walls were formed all around the nuclei. Alveolus formation only occurred when nuclei had attained a dense distribution in the layer of cytoplasm aligning the wall of the central cell. When nuclei divided within the alveoli, cell plate formation resulted in the formation of mononuclear endosperm cells along the embryo sac wall. When the walls of the alveoli grew towards the centre of the embryo sac, alveoli regularly closed leaving space for enlargement of the remaining alveoli. In this way endosperm cells enlarged going from the periphery to the central area of the embryo sac. The microtubular cytoskeleton was visualized in the nuclear, alveolar and cellular endosperm. The pattern observed, showed that the organization and function of the microtubular arrays was as generally found during endosperm development.
The pattern of total transcription activity in terms, of steady state levels of poly(A)+ containing mRNA during callus initiation and somatic embryogenesis in a high (A188) and a low (A632) embryogenic line of maize was analyzed using digoxigenin labelled oligo-dT probes. A gradual increase and a preferential accumulation of label was observed in both lines, differing temporally up to 4 days in culture. In the A188 line of maize the callus gave rise to somatic embryos. The globular embryos showed less label than the callus; this labelling was mostly present in the basal part of the embryos. At a later stage upper embryogenic and lower non-embryogenic layers were observed in the A188 callus, showing conspicuous differences in the amount of label. In the late globular stage the poly(A)+ RNA signals were seen all over the embryo but at the junction of the suspensor and the callus tissue no label was observed.
The paper analyses the distribution and occurrence conditions of Loiseleuria procumbens in the Spanish Pyrenees. The species represents a typical arctic-alpine element in the flora of Europe. In the Pyrenees it reaches its southernmost European localities. The Pyrenean populations of the species are not numerous in the majority of the localities. L. procumbens occurs most frequently in the alpine and subalpine zones, at altitudes between 2100 and 2650 m, with a minimum at 1750 m and a maximum at 2900 m. It has been reported nearly exclusively in the siliceous substrata, and predominantly on the north-facing slopes, on the regosols and/or on flat tops of rocks. It forms its own communities, mostly included into the Loiseleurio-Vaccinion alliance, and rarely enters associations of the Festucion airoidis and Rhododendro-Vaccinion alliances. Its typical community, Cetrario-Loiseleurietum procumbentis, is found only in the eastern and central parts of the Spanish Pyrenees. Peer reviewed
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.
The organel-sequence in ovular cells of Pinus silvestris was investigated by light- and electronmicroscopy during the post-pollination and pre-fertilization period. Changes in starch and lipid storage suppose starch to be a pool for lipid synthesis and a reserve for ovule development. The base nucellus plays an important role in the distribution of metabolites all over the ovular tissues. Lipid, starch and callose are of interest for the cells to protect them against low temperatures by means of isolation, antifreeze and plug formation respectively.
Paper deals with the results of statistical analysis of the type of frequency distribution of species occuring in the field layers of two forest phytocoenoses. In the both cases frequency distributions were ranged out for the surface area of 1, 2, 4, 8, 16, 32 and 64 m2. The types of frequency distributions were determined on the grounds of the values of Fisher's and Pearson's K coefficients. Analysed distributions were classified into Pearson's system. Also the size of the sample plot at which the empirical frequency distributions were symetrical, from the statistical point of view, nad where they were U-shaped was determined.
In this paper the author presents a review of the previous studies on Dactylis L., dealing with cytology,genetics, experimental studies and evolution. Following cytotypes of Dactylis are distributed mostly in Central Europe: 16 diploids, 7 tetraploids and also 2 hexaploids in North Africa. Some aneuploids and accessory chromosomes were also found in this genus. Data dealing with karyotypes of some taxa, and geographical distribution of cytotypes are also listed. Selected problems concerning crossing within diploids as well as tetraploids and also between diploids and teraploids were presented. Some opinions regarding the evolution in the genus Dactylis were also demonstrated. In all these hypotheses the following diploids are considered to be the oldest: D. smithii Link subsp. smithii, D. g. subsp. aschersoniana (Greabn.) Thell. and D. g. subsp. himalayensis Dom.
The influence of optimal concentrations 5 × 10-6M - 10-6M of 11-deoxycorticosterone (mineralocorticoid) and prednisolone (glucocorticoid) on the growth (fresh and dry weight) and content of soluble proteins, reducing sugars and nucleic acids in the green alga Chlorella vulgaris (Chlorophyceae). Both corticosteroids at concentration 5 × 10-6M were most strongly active metabolically between the 5th-15th day of the cultivation and this probably was caused by their chemical biotransformation. The applied corticosteroids induced the strongest stimulative effect on the content of soluble proteins in the range of 167-196% and reducing sugars (233-275%) when compared to the control (100%). Prednisolone showed lower stimulative activity on the content of proteins But 11-deoxycorticosterone showed weaker stimulation of on the content of sugar. Both of the corticosteroids showed a stimulating or inhibitory influence upon the content of nucleic acids in C. vulgaris cells without regard to the concentration.
Seasonal activity of cambium has been investigated in Salvadora persica L., one of the commonest evergrenn tree of northern India, from March, 1974 to February, 1975 in the main stem and the branch. Secondary vascular cambium behaves abnormally on the xylem side, by producing xylem and phloem in succession, resulting in the formation of interxylary phloem. It has a storied (sitratified) cambium organization, comprising short fusiform and isodiametric ray initials. The fusiform initials show characteristically beaded cell walls due to the presence of primary pit fields and are uninucleate. These are highly vacuolate during the active period. The cambial activity starts in the month of March, reaches the peak in August and finally slows down in the main stem. In an young branch, however, it is initiated in March-April and reaches the peak in July and then declines till November. It once again showed an upward trend gradually. It appears that the initiation of the combial activity in this tree takes place by a hormone produced in the newly formed leaves, coupled with the high rainfall, enhanced relative humidity, optimum temperature, and short-day conditions. Size measurements for the fusiform initials showed considerable variations during the span of a year. A comparision of the organization of three types of phloem 'normal', 'included' and 'internal' occurring in this plant has also bean presented.
Among the offspring of a problematic form of Achillea sp., a 2n = 126 seedling which probably arose as the result of fusion of unreduced octo- and hexaploid gametes (72 + 54) was found along with seedlings having an octaploid chromosome number (2n = 72). Putative paths leading to the formation of problematic octaploid forms and plants with 126 chromosomes are discussed.
Pythium species and environmental factors in various types of water bodies (2 springs, 2 rivers, 3 ponds and 6 different trophic lakes) were studied. Samples of water were collected every two months (springs, rivers, ponds) and every three months (lakes) in the years 1996-1999 for hydrochemical analysis and in order to determine the Pythium species content. From springs rivers and ponds collected were also ice blocks for determinations of presence of Pythium species. Buckwheat- and hemp-seeds, cellophane and snake exuviae were used as bait. Forty-five species of Pythium were found in various types of water bodies. Pythium acanthicum, P. complectens, P. complens, P. diameson, P. dissimile, P. elongatum, P. lucens, P. megalacanthum, P. nagae, P. oedochilum, P. oryzae, P. palingenes, P. periilum and P. polysporum were recorded for the first time in Poland. The largest mean number of species was observed in spring Cypisek, a bit fewer in spring Jaroszówka and lake Białe (oligotrophic-like waters). The lowest mean number of Pythium species was noted in pond Akcent and Pałacowy (polytrophic waters). In all types of water bodies the higest mean number of species was found in winter,and the lowest in summer.
Reduction of photosynthetic activity by 6 or 7 days of preshading increased to some extent migration of 14C-assimilates to the stem and decreased that to the roots. Restriction of roots demand for assimilates by feeding them with sucrose decreased the share of roots in 14C-export from the blades and increased 14C-transport to the other acceptors: stem and apical part, mainly in plants with roots actively accumulating radioactive substances in control plants, in which competition for assimilates was strong. A very small or even no effect of sucrose was observed in seedlings with relatively lower activity of roots as well as in the plants translocating labelled assimilates in darkness.
The experiments were carried out to study the effect of salt-stresses and ABA on the growth, photosynthesis and translocation of assimilates in bean plants. It was planed to reduce the content of GA3 and cytokinins and increase ABA content in salinized plants. The results show that salt-stress (NaCl and concentrated nutrient solution), reduce all the investigated processes in a different degree. NaCl-stress retarded most seriously growth of apical part and blades in contrast to 7-times concentrated nutrient solution decreasing mainly the rate of root and blade growth. Photosynthesis and 14C-translocation of 14C-assimilates were retarded more seriously by NaCl than by 7-times concentrated nutrient. solution. In the case of seriously stressed plants GA3 and cytokinins (more effectively) reversed the ,negative effect of stress conditions both on the photosynthesis and on the 14C-tramslocation. On the basis of the obtained results, it seemes that changes in the rate of investigated processes in salinized plants are due to hormonal disturbances which cause directly or indirectly retardation of photosynthesis and trans-location of assimilates.
Roots of whole 3 week-old seedlings of maize were exposed for 24 h to a solution of PbCl2. The concentrations of Pb were: 0, 200, 400, 800, 1200, 2400 mg dm-3. The amount of Pb taken up by roots was independent of the concentration of this element in the medium. The Pb taken up by shoots increased linearly with increasing treatment concentration. Pb caused: concentration-dependent inhibition of photosynthesis (PS), transpiration (T), 14CO2 uptake and incorporation of label into photosynthetic products. The largest limitation by Pb of the flow of photoassimilated carbon occurred into starch and sugar phosphates. Among the water-soluble photoassimilates, the largest limitation of carbon flow occurred into organic acids and sugars and the smallest into amino acids.
The aim of present study was lo compare the role of strawberry daughter plant in the translocation of assimilates, with that of roots in other species. Only in the autumn's experiment (No 1), where translocation was relatively low, daughter plants removal influenced a little migration of assimilates to the runner. In all the other cases a marked decrease of ¹⁴C-lranslocation to the runner, deprived of daughter plant was observed, as compared with intact plant. This effect was more pronounced in older runners, after excision of bigger plants. The "filling" of the tissue, of intact, younger runners with ¹⁴C-assimi lates, seems to be delayed as compared with that of older ones. The distribution of labelled compounds in radial direction, depended on the age of runner, but not on the presence of daughter plant. In younger runners, more labelled assimilates were located in the outer layer, inversely to the older ones. All these facls seems to suggest, that the daughter plant - an acceptor of assimilates, influence the velocity (or/and rate) of translocation of assimilates in strawberry, in different degree depending on its "sink power". This effect was similar to that, exerted by roots removal, or some part of them, reported in previous paper, (Starck 1964a, b). The mechanisms of these effects are still little known.
In young seedlings of bean plants translocation of ¹⁴C-assimilates continued at least for 2 hrs after ¹⁴C-bIades removal. In this period the stem, (especially the epicotyl), and petioles, become the main donor of ¹⁵C-assimilates. These organs exported ¹⁴C-photosynthates mainly to the apical part of the stem with the youngest leaf and to the roots. Petioles and stem exported 80% of the cthanol soluble compounds and also some part of the ¹⁴C-substances previously incorporated into the 80%-ethanol insoluble fraction. Derootment caused: 1) an increase of upward and decrease of downward translocation, 2) an accumulation of ¹⁴C-substances in the petioles and 3) decrease of ¹⁴C-incorporation into the ethanol insoluble fraction, as has been already observed in a previous paper. In plants deprived both: of blades and roots, translocation of organic substances was greatly diminished. The results obtained seem to suggest, that mobilisation of organic substances may involve some sort of pulling as well as pushing forces.
In a series of radish plants, with very thin hypocotyl and with a normal storage organ, the rates of photosynthesis, photorespiration and dark respiration did not differ. Therefore, the conclusion may be advanced, that translocation to the swollen hypocotyl is not determinated by the photosynthetic productivity, but rather the by storage capacity. To check it this is connected with an unbalanced hormonal content, plants were treated with lanoline paste, with IAA, GA3, zeatin and all three in mixture or with injections of GA3-water solution into the swollen hypocotyl. In young radish plants, with high rate of growth of aerial parts, treatment with the above mentioned substances stimulated 14CO2-assimilation and increased retention of assimilates in 14C-donors, probably owing to retardation of their senescence. It increased the competition for photosynthates between shoot and storage organ. In older plants, in the stage of accumulation of nutrients in the swollen hypocotyl, IAA +GA3+zeatin did not affect 14CO2-assimilation, but in plants treated with growth regulators separately, assimilation decreased; IAA and GA3 stimulated transport and accumulation of labelled substances in the swollen hypocotyl. On the basis of experimental data the conclusion may be advanced that responsiveness of the particular organs and processes to growth regulators depends on the stage of plant development. Phytohormone did not changed quantitatively the pattern of 14C-assimilates distribution. They stimulated processes with preference for particular stages of development.
The experiments with different-aged buckwheat (Fagopyrum esculentum Mnch.) and white mustard (Sinapis alba L.) plants showed that the sub-apical and middle leaves, before they had reached their approximate final sizes, had the highest rates of 14CO2 absorption. The intensity of this process decreases in each leaf with age of the plant. White mustard leaves showed a little higher absorption rate of 14CO2 than analogous leaves of buckwheat plants. In the investigated leaves no close relationship between the intensity of 14CO2 assimilation and chlorophyll a and b concentration was observed. Some possible reasons for the higher intensity of photosynthesis in the sub-apical leaves are discussed.
The number of chromosomes was determined in mitosis, the course of meiosis was analysed and the degree of pollen viability determined in plants with intermediate enzymatic phenotypes between Aconitum napellus and A. variegatum. One allotriploid plant was found with 2n=24 and a group of plants with 2n=32 showing disturbances in mitosis and meiosis. In mitosis somatic reduction and polysomaty were observed and in meiosis monads, diads, triads and polyads were present. These plants are considered as introgressive hybrids arising owing to a small scale gene flow from A. variegatum to A. napellus.
The variability of six enzymes in pure and mixed populations of Aconitum napellus and A. variegatum, both from the Tatra Mountains was analysed by means of electrophoresis on starch and polyacrylamide gels. The enzymes differentiating the studied species are: glutamate dehydrogenase, isocitrate dehydrogenase, esterases and peroxidases. A group of plants was isolated with phenotypes intermediate between A. napellus and A. variegatum. Among them were most probably both F1 and introgressive hybrids.
The experiments were conducted on developing triticale var. Grado caryopses. Treatment of freshly gathered, unripe triticale caryopses with abscisic acid (ABA) decreased their precocious germination throughout the entire period of development and ripening. The more mature the embryos that were germinated, the lower the inhibition by ABA. This indicates that the sensitivity of the embryo to ABA decreases during the course of caryopsis development and that the role that this hormone can play in the prevention of spouting in ears during the final stages of maturation, is limited. A known inhibitor of gibberellin synthesis, the retardant AMO-1618, was also tested in these experiments. This compound caused the reduction of germination capability only in the initial stages of development of triticale caryopses. Its most visible effect was noted during the germination of caryopses collected 30 days after flowering. The effect of this compound on the precocious germination of isolated embryos also decreased as the degree of maturity of these embryos increased. In the opinion of this author, this is connected with the fact that intense gibberellin synthesis and accumulation occurs only in the early stages of caryopsis development.
Effects of GA3 (10-11-10-4 M) and AMO-1618 (10-6-10-4 M) on the development of generatively matured thalli of Chara vulgaris were investigated during 21-day culture of plants in axenic conditions. It has been found that in the main bud the divisions of apical cells of the thalli are not stimulated by GA3, whereas in the lateral buds the cell divisions are stimulated by higher GA3 concentrations. Subsequent mitotic activity of the apical cells in the branches of the main axis is not stimulated by GA3, whereas the lateral buds of these branches are activated. The development of rhizoids in younger nodes is accelerated by high GA3 concentrations. The elongation of the polynuclear, internodal cells of the main axis and that of pleuridia are inhibited proportionally to the GA3 concentration. AMO-1618 stimulates the development of new nodes, elongation of internodes and delays the activation of lateral buds as well as the formation of rhizoids. These results suggest that the GA3-induced inhibition of elongation of the thalli and diminution of the apical domination is connected with a high level of endogenous gibberellins in the generatively matured thallus.
The distribution and ecology of Chara braunii Gmellin 1826 in Poland is described, based on herbaria collections, literature data and own investigations. Maps showing the distribution of Ch. braunii are presented, as well as a list of localities with brief descriptions of the habitats. Additionally, some remarks on the distribution limit in the northern hemisphere are given.
A species new in the Polish flora, Spirogyra lagerheimii Wittr, was found in the old riverbed of the Raba River in Mszana Dolna (Nowy Sącz Voivodship) and in a peat bog in Magdalenów (Piotrków Voivodship). Figures showing hitherto unknown scalariform conjugation, germinating zygotes, inflated vegetative cells in conjugating filaments are shown.