Nowadays a number of lignans (arctigenin, matairesinol, pinoresinol and phillygenin) have come to the fore in research due to their various biological activities. In this paper the accumulation of these constituents in leaf extracts of Forsythia plants (F. intermedia, F. ovata 'Robusta’ and `Tetragold', F. suspensa, F. viridissima) was quantified using a new isolation method, supercritical CO2 fluid extraction. The total phenolic and flavonoid contents, the antioxidant capacity and the aglycone lignan profile were determined in leaf extracts of Forsythia species. Within the phenols, the flavonoids were only present in small quantities, but the amount of aglycone lignans was extremely high. F. ovata `Robusta' had the highest total lignan content (103.8 mg/g) of all the Forsythia species. The main lignan in this species is arctigenin, which normally makes up about 60% of the total lignan content, but in the case of F. ovata `Robusta' this value was 96.1%. Since this arctigenin content is outstanding compared to that of other Forsythia species, it could be promising to develop a fermentation technology for the production of this natural compound.
In contrast to most angiosperms, Torenia contains a naked embryo sac and therefore has been considered since many years as an exciting model plant to study the double fertilization process of flowering seed plants. It is thus not surprising that the isolation of protoplasts from the female gametophyte has been reported already 20 years ago by Mol, the isolation of megaspores and megagametophytes has been published by the authors of this manuscript in 1996 and in 1999. The isolation of the male gametophyte and of sperm cells was published by the authors in 2004. The isolation of viable Torenia sperm cells is a crucial part of the elaboration of an in vitro fertilization system. Torenia sperm cells were isolated from in vivo — in vitro cultured pollen tubes. In this system pollen tubes first grow inside a cut style then follow their elongation in a solid isolation medium. The medium contained agarose in order to detain pollen tube contents. Released sperm cells and enzymatically isolated egg cells were collected and handled using glass micropipettes and transmitted to an electrofusion apparatus or polyethylene glycol containing media for fusion probes.
According to previous studies some anatomical features seem to be connected with resistance or susceptibility to scab caused by Venturia ineaqulis (Cke./Wint.) in case of a given cultivar. Study of leaf anatomy of three scab resistant (‘Prima’, ‘Florina’, MR–12) and two susceptible (‘Watson Jonathan’, ‘Golden Delicious Reinders’) apple cultivars have been made. Preserved preparations made of leaves has been studied by light microscope. Studied parameters were: thickness of leaf blade, thickness of palisade and spongy parenchyma, thickness of epidermal cells, thickness of the cuticle. By measuring leaf thickness and epidermal cell thickness visible differences appeared in certain cultivars, while most conspicuous difference has been shown in thickness of the cuticle.
Phaeodactylum tricornutum UTEX 640 strain of microalgae was screened under different culture conditions for their capacity to produce eicosapentaenoic acid (EPA) the most abundant polyunsaturated fatty acid (PUFA). In our experiments, the effect of sodium chlorid, nitrogen source, phosphate, initial pH, as well as the CO2 content of the medium on production of the eicosapentaenoic acid (EPA) by P. tricornutum were investigated. The EPA content of biomass was enhanced by the low pH of the medium, with increased concentrations of B17 vitamin and nitrate, and also with decreasing concentrations of sodium chlorid. The EPA is most likely associated with polar (membran) lipids and the role of EPA appears to be involved with membran permeability in microalge. The synthesis of phospholipids, enhances the EPA content of the cells, as expected. The maximum EPA yields were observed under optimum culture condition 43 — 48 mg/g of dry cell weight.
Anatomical relations of root formation are traced throughout the life cycle of the strawberry plant from the germinating seed up to the runners of the adult plant. Histological picture of the root changes a lot during the development of the plant. First the radicle of the germ grows to a main root, which makes branches into side roots and later adventitious roots are formed on the growing rootstock or rhizome. The anatomy of the different types of roots is also conspicuously different. First tiny branches appear relatively early after germination on the seedling's radicle, but soon the hypocotyl of the seedling thickens and develops side roots, which are already somewhat stronger. During this interval, the first true leaves are formed. The 4th or 5th of them being already tripartite, and the initiation of new roots extends into the epicotylar region of the shoot. The second years growth starts with the development of reproductive structures, inflorescences and runners starting from the axils of the new leaves. Near the tips of the runners below the small bunch of leaves, new root primordia are initiated. The tiny radicle of the germ develops a cortical region of 5-6 cell layers. Cells of the central cylinder are even smaller than the cortical parenchyma and include 3-4 xylem and 3-4 phloem elements as representatives of the conductive tissue. Roots originating from the shoot region are much more developed; their cortical zone contains 17-20 cell layers, whereas the central cylinder is about half as large. In the next year, new roots are formed at the base of the older leaves. These roots differ hardly from those of the last season in size and volume, however, they are recognised by colour and their position on the rhizome. The roots of the last year are dark, greyish-black, and grow on the lower third length of the rhizome, on the contrary, the new ones, on the upper region, are light brown. Roots starting from the shoot or rhizome are, independently from their age or sequence, mainly rather similar in size and diameter, thus being members of a homogenous root (homorhizous) system, i.e. without a main root. Plants developed and attained the reproductive phase develop in the axils of the leaves runners being plagiotropic, i.e. growing horizontally on the surface of the soil. The runners elongate intensely, become 150-200 mm, where some long internodes bear a bunch of small leaves and root primordia on short internodes and a growing tip. Runners do not stop growing, generally, further sections of 15-25 cm length are developed according to the same pattern, with small leaves on the tip. The growing tip of the runners is obliquely oriented, and small, conical root primordia are ready to start growing as soon as they touch the soil. The roots penetrate the soil, quickly, and pull, by contraction, the axis of the runner downwards, vertically, developing a new rhizome. The short internodes elongate a little and start developing adventitious roots. At the end of the growing season, the plantlets arisen on the rooted nods of runners are already similar to the original plants with homogenous root system. On the side of the adventitious roots, new branches (side-roots) are formed. The root-branches are thinner but their capillary zone is more developed being more active in uptake of water and nutrients. The usual thickening ensues later.
The process of in vitro rooting and the anatomical characters of in vitro and ex vitro leaves and roots of Prunus x davidopersica 'Piroska' were studied. Best rooting percentage (50%) and highest root number (5.0) was achieved in spring on a medium containing 0.1 mg/I NAA + 30 g/1 glucose. At the end of rooting the parenchyma of the in vitro leaves was more loose and spongy, than during the proliferation period. In the first newly developed leaf of an acclimatised plant, the parenchyma was much more developed, contained less row of cells and less air space too, compared to the leaves developed in the field. The in vitro developed root had a broad cortex and narrow vascular cylinder with less developed xylem elements, but at the end of the acclimatisation the vascular system became dominant in the root.
Two strains of Pseudomonas syringae subsp. savastanoi were isolated from Forsythia sp. and Nerium oleander in Hungary in 1997. The effects of growth regulators produced by the bacteria were studied in different experiments. The strains were co-cultured with Sorbus redliana in vitro shoots without being in contact with the plant on solid media. Further culture filtrates in different concentrations were added to the culture medium. The growth regulators presented in the agar caused knot formation on the shoots and on the leaves in both kinds of culture. There were significant differences in the cultural and physiological characters, auxin and cytokinin activity of the strains of different origin.
The most important components of fruit drop are: the rootstock, the combination of polliniser varieties, the conditions depending of nutrition, the extent and timing of the administration of fertilisers, the moments of water stress and the timing of agrotechnical interventions. Further adversities may appear as flushes of heat and drought, the rainy spring weather during the blooming period as well as the excessive hot, cool or windy weather impairing pollination, moreover, the appearance of diseases and pests all influence the fate of flowers of growing and become ripe fruits. As generally maintained, dry springs are causing severe fruit drop.
In analysing the endogenous and environmental causes of drop of the generative organs (flowers and fruits), the model of leaf abscission has been used, as a study of the excised, well defined abscission zone (AZ) seemed to be an adequate approach to the question. Comparing the effects active in the abscission of fruit with those of the excised leaf stem differences are observed as well as analogies between the anatomy and the accumulation of ethylene in the respective abscission tissues.
Immature in vitro leaves showed similar structure of the mesophyll tissue to the immature field-grown (in vivo) leaves of Prunus x davidopersica `Piroska'. Mature leaf anatomical characteristics of in vitro plantlets differ from the field-grown plants. The mesophyll tissue of in vitro plantlets were thinner than the in vivo plants and consisted of only one layer palisade parenchyma, the shape of the cells and the structure of spongy parenchyma basically differed from the field-grown plants. In the case of Sorbus rotundifolia similar anatomical differences were found both in vitro and in vivo as in the case of Prunus x davidopersica `Piroska'.
The rain induced fruit cracking is a big, serious and costly problem for cherry growers. Cracked fruits lose their value and they are not marketable because of the poor fruit quality. Cracked fruits have different storage diseases and shorter storage and shelf life.
There are many influencing factors of the cherry fruit cracking such as: water uptake; fruit characteristics (fruit size, fruit firmness; anatomy and strength of the fruit skin, stomata in fruit skin, cuticular properties, osmotic concentration, water capacity of the fruit pulp, growth stage of the fruit,); orchard temperature and other environmental conditions;
The most effective protection technique is the plastic rain cover over the tree rows. The installation of these equipments is too expensive for the cherry growers. That is the reason why researchers tried to find other less expensive and sufficiently effective ways against the Lim induced fruit cracking.
Several calcium formulas: calcium chloride (CaC1,), calcium hydroxide (Ca (OH)2) and calcium nitrate (Ca(NO3)2 ) can be sprayed in appropriate concentration. Spraying with other mineral salts (aluminium and copper salts, borax) and PBRs (Plant Bioregulators) may be also effective to reduce fruit cracking.
Comparitive histological studies were made on the underground and the aboveground stem parts of Rosa rugosa taken from one year old suckers. The underground stem parts were characterized with thicker primary cortex, phloem and pith, weaker phloem fibers, wider cambial zone, medullary rays, xylem and phloem rays as compared with the aboveground stem parts. The most marked differences in the underground stem parts were in the wide cambial zone and in the development of some adventitious roots.
In the present study histology of the leaves of strawberry (Fragaria ananassa Duch.) variety Elsanta was the objective, which has been performed with the beginning of seedling stage, cotyledons, primary leaves and later true leaves, first cataphyll of the runner shoot as well as the bracteoles of the inflorescence. Structures of the leaf blade, the upper and lower epidermis, the petiole have been also observed. The leaf blade of cotyledons already contains a typical palisade as well as spongy parenchyma tissues, i.e. being bifacial showing a structure similar to that of the true leaf. However, the petiole displays differences from the true leaf. There are a narrow (4-5 layer) primary cortex and a tiny central cylinder. Primary leaves bear already hairs on the adaxial surface and the transporting tissue-bundles are recognised in cross sections having a "V" shape. The first true leaf composed by three leaflets is of a simple structure showing characters reminding of cotyledons and primary leaves. Leaves of intermediate size continue to grow, whereas their inner anatomy changes dramatically. In the central region of the leaflets, near to the main vein, a second palisade parenchyma appears, further on, transporting tissue bundles are branching in the petiole. Collenchyma tissues enhance the stiffness and elasticity of the petiole. Older true leaves develop thick collenchyma tissues around the transporting bundles being represented by increasing numbers. The doubled palisade parenchyma layers of the leaf blades are generally observed. The cataphylls of the runners have a more simple structure, their mesophyll is homogenous, no palisade parenchyma appears. It is evident that leaves grown at successive developmental stages are different not only in their morphological but also anatomical structure. There is a gradual change according to the developmental stage of the leaves.
The traditional methods for vegetative propagation of apple and its varieties are the T-budding, and the winter grafting, but this latter way is a difficult and expensive procedure.
In our experiment carried out in the Fruit Tree Nursery Soroksár, the healing process of chip- and T-budded apple trees 'Jonagold' on MM 106 rootstock was studied.
The budding (T- and Chip-) was made in the first week of August, samples for microscope examination were taken monthly after this time until leaf fall.
The investigated part of plants was made soft with 48 % HF (hydrogenfluoride), then cross and longitudinal section were made and examined by microscope.
Based on analysis of microscope pictures in case of Chip-budding, it was established, that development had started quickly after budding on the rootstock and scion too. But the callus originated almost entirely from the rootstock tissue as new parenchyma cells fills the gap between the two components of graft (scion and stock), becoming interlocked and allowing for some passage of water and nutrients between the stock and the scion. This quantity of callus in case of T budding was under the scion buds larger, than the Chip-budded unions, where the thickness of callus mass is uniformly thick round the chip. The large mass of callus pushes the scion bud outwards from the shoot axis, which later results in a larger shoot-curvature above the bud union.
Following this process on the Chip-budding it can be observed also, that a continuity of the cambium is established between bud and rootstock. Then the newly formed cambium started typical cambial activity, forming new xylem and phloem.
Later the callus begins to lignify, and it is completed within about 3 months after budding.