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  • Floral biological studies on pear cultivars in relation to fire blight susceptibility
    25-30.
    Views:
    184

    Floral biological characteristics that may influence cultivar susceptibility to fire blight were studied in 10 pear cultivars in two Hungarian orchards from 1999 to 2003. The receptaculo-ovarial, automorphic nectary is usually bigger in tolerant cultivars than in susceptible ones. Nectary stomata are meso- or xeromorphic. Susceptible cultivars tend to have more xeromorphic stomata, where guard cells are located 1-3 cell rows below the epidermis. The size of nectar chambers is usually smaller in susceptible cultivars. Floral nectar, consisting mainly of glucose and fructose, is more abundant and less concentrated if the cultivar is susceptible to fire blight. The amount of chlorogenic acid was higher in the flowers of tolerant cultivars than in susceptible ones.

  • Isolation of living sperm cells and in vitro fusion of Torenia fournieri gametes
    81-85.
    Views:
    118

    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.

  • Sunburn incidence of apples is affected by rootstocks and fruit position within the canopy but not by fruit position on the cluster
    45-51.
    Views:
    278

    Authors investigated sunburn incidence of apples on the combinations of three different growth inducing rootstocks (M.9,MM.106 and seedling) and five varieties (‘Smoothee’, ‘Golden Reinders’, ‘Granny Smith’, ‘Gloster’ and ‘Jonagold Jonica’). Symptoms were classified as sunburn browning, sunburn necrosis and photooxidative sunburn. The frequency of symptoms was recorded at various parts of the canopy (N, E,W, S, and lower canopy, upper canopy) and on the cluster (terminal, lateral). Cultivar susceptibility varied between 0.30 and 5.65% on M.9 rootstock, ‘Granny Smith’ seemed to be the most susceptible cultivar whereas relatively low percentage of damaged fruit was observed for ‘Gloster’. On MM.106 and seedling rootstocks, damage level was significantly lower than on M.9. Remarkable differences were not observed in the share of the three sunburn types between cultivars. The most common symptom observed was sunburn browning. Far less fruit was affected by sunburn necrosis and photooxidative sunburn. Photooxidative sunburn symptoms were not found on ‘Granny Smith’ and ‘Gloster’ fruits on MM.106 rootstock. Latter cultivar did not show sunburn necrosis symptoms either. With increasing growing vigor of the rootstocks the share of sunburn browning increased. Fruits with sunburn symptoms were found in a great majority on theW quadrant of the trees. This was true for all cultivars. Remarkable differences in the location within the canopy of affected fruits between the three types of sunburn were not observed. Specific distribution of sunburned fruit was observed along the vertical axis of the canopy, too. Most of the damaged fruit were found in the upper canopy. This is particularly true for trees on vigorous stocks such as MM.106 and seedling. On M.9 rootstock, depending on cultivars 5.9 to 38.9% of sunburned fruit was located in the lower canopy. Most common symptom in the lower canopy was the sunburn browning, however symptoms of sunburn necrosis were not found at lower canopy level. Low rate of photooxidative sunburn was observed such lower canopy conditions. Sunburn incidence was very similar on king or side fruit. Significant differences were not found in the share of each sunburn types between fruit positions on the cluster. This was not influenced by rootstocks either.

  • Callus induction on standard type Cymbidium cultivars
    108-110.
    Views:
    163

    Tissue cultured Cymbidium PLBs (protocormlike body) were used as starting material to induce embryogenic callus which could serve as objects of genetic transformation. We obtained callus using two methods. The first method was culturing the PLB segments for one month in liquid MS medium in the presence of 0.5 mg/1 benzyladenine and 0.05 mg/1 naphtylacetic acid followed by cultivation on the same composition solid medium with 0.5 g/l activated charcoal for an additional month. Callus formation was observed on 30% of the explants. The second way was to propagate the PLB segments on solid MS medium supplemented with 1 mg/1 thidiazuron. In these cultures we also observed callus formation on 20% of the explants.

  • Improved evaluation method for reliable distinction of poppy (Papaver somniferum L.) cultivars
    68-73.
    Views:
    200

    Investigating seven Hungarian standard cultivars (i.e. 'A1’, 'Kék Gemona', '13C-2`,'Kék Duna', `Kompolti M’, `Gödi N',

    'Kozmosz) it was proved that for the reliable distinction between cultivars a complex analysis is necessitated. Because of the large morpho­phenological and production-biological plasticity of the species qualitative and quantitative features as well as alkaloid accumulation characters have to be evaluated simultaneously applying discriminant analysis.

    It was proved by the investigations that some of the qualitative and quantitative characters included into the DUS evaluation procedure have slight importance for reliable distinction. As an example the majority of cultivars show high inhomogentity in such characters like the shape of stigmatic disc, the number of stigmatic lobes etc. Furthermore these characters never had been chosen for the goal of any practical selection and are modified by the weather conditions as well.

    In the evaluation process the alkaloid accumulation characteristics (both qualitative and quantitative ones) have to be evaluated on a higher rank. For instance the high accumulation level of morphine in cv. 'A1' (10.5 %o), exceptionally high narcotine accumulation in 'Kék Gemona' (7.8 %o), or the low morphine accumulation level in cv. 'Kozmosz' (1.1 %o) proved to be proper characters for their distinction, alone. However, at the same time the weather conditions existing at the time of experiment have to be taken into consideration. From practical point of view, the years rich in precipitation and poor in sunshine are less suitable for distinction of cultivars selected for higher alkaloid accumulation, especially for production of codeine and thebaine characterized by a higher methylation level. Based on the example of 'Kék Gemona', the accumulation level of morphine decreases from 7.4 %o to 4.1 %o under such conditions, while thebaine and codeine disappear, practically.

     

  • Some relationships between soil and nutrient requirements and nutrient supply of pepper (Capsicum annuum L.) with respect to types grown in Hungary
    93-105.
    Views:
    192

    Exports and local marketability of both pepper protected cultivation and open field pepper production depend on whether we succeed in the near future achieving developments capable of bringing about significant improvement of yield and quality, as well as enhanced yield security. Results from experiments and surveys carried out on farms involved in production suggest that nutrient management is one of the factors whose development could considerably improve the marketability of pepper. Technological improvements in the field of nutrient supply are also urged by the more and more demanding environmental regulations, so it is inevitable to introduce a balanced system of nutrient supply system for pepper as well. The article is a collection and summary of the relevant results of 30-year experimental work in Hungary.

  • In vitro shoot multiplication of apple: comparative response of three rootstocks to cytokinines and auxin
    36-39.
    Views:
    260

    Shoot multiplication responses of rootstocks cvs. M.26, MM.106 and JTE-H to different concentration of BA, BAR and IBA in eight various combinations were tested on MS-medium. The effect of hormones depended on genotype, type of cytokinin and interaction of cytokinin and auxin. Shoot multiplication was significantly enhanced with the use of BAR as cytokinin. High multiplication rate could be achieved in cvs. M.26, MM.106 and JTE-H: 7.7, 6.9 and 9.9 shoots per explant, respectively.

  • Farm-scale evaluation of two widely used sanitation practices for reducing primary inoculums of apple scab in organic apple production
    15-18.
    Views:
    211

    Effects of two widely used sanitation practices were evaluated at farm-scale level on leaf degradation and primary infection by Venturia inaequalis in an organic apple orchard (Eperjeske) on two apple cultivars (Jonathan and Prima) from 2011 to 2013. The tested sanitation practices were eradication of fallen leaves by collection and disc cultivation. Treatments of eradication of fallen leaves by collection and disc cultivation reduced signifi cantly (P< 0.001) leaf litter density with 70–85 and 40–55%, respectively, compared to untreated plots in both years. Above treatments in the same order reduced spring scab incidence with 40–50, and 10–20%, respectively, compared to untreated plots. Incidence of leaf scab in autumn was not signifi cantly lower (P< 0.05) in the treatments in the years.

  • Security of growing habits and bud formation of German sour cherry varieties
    45-48.
    Views:
    238

    Intensive sour cherry production is concerned to find the most productive varieties under special growing conditions. High planting density, adapted to manual picking or on the other hand to mechanical harvesting. Almost as important is the prolongation of the ripening season by enlarging the choice of varieties. Unfortunately, three of our four leading commercial varieties are ripe almost at the same date.
    Therefore, new varieties ought to be examined thoroughly. In the Pallag Experimental Station of the Debrecen University, five European varieties have been grown (’Schattenmorelle’, ’PI-SA 12,100’, ’Jade’, ’Gerema’, ’Achat’) and a Hungarian one, ’Debreceni bôtermô’ used as a check for the experiments to compare their growing and yielding habits in 2010. The plantation was three years old, standing on Prunus mahaleb rootstocks, in high density (5 x 2 m) and trained to slender spindle crowns. The results are proving that some of the varieties in
    question are suitable to prolong the harvesting season. Growing habits and yields of the varieties related to the variety ’Debreceni bôtermô’ were similar or even better as ’Jade’, ’Gerema’ and ’Achat’. The ’Jade’ excelled with its vitality and ’Gerema’ with its generative character. Further studies are expected to prove the utility of
    one of them at least to enlarge the ripening season on the fruit market.

  • Effect of water supply on canopy temperature, stomatal conductance and yield quantity of processing tomato (Lycopersicon esculentum Mill.)
    13-15.
    Views:
    336

    Tomato (Lycopersicon esculentum Mill.) is one of the most extensively cultivated horticultural crops in the world.Water supply is important for yield quantity and quality. The aims of the present study were 1) to evaluate the canopy temperature and the stomatal conductance on processing tomato substances with different water supply, 2) to investigate the effect of different water supply on yield quantity. There were two irrigated treatments, one of them was the reguralry irrigated plant stand which got 333 mm water during investigated period, including the precipitation and the other was the cut off substance which means the irrigation (drip) was stopped at the beginning of the ripening process and there was a control as well which got 189 mm precipitation. The canopy temperature was measured row by row with a Raytek MX 4 type infrared remote thermometer. The stomatal conductance was measured by Delta-T AP4 type porometer. There were significant differences between the control and irrigated plants according to the water supply which was formulated the canopy values. The plants with a deficient water supply were decreased the transpiration rate, therefore its cooling effect didn’t show up. The regularly irrigated tomato plants’ yield exceeded the unirrigated ones more than twice. It is emerged from the study that the irrigation has a positive effect on the amount of the harvestable yield in this year type.

  • Nectar production of pear (Pyrus communis L.) cultivars
    67-75.
    Views:
    299

    Detailed studies were made on the nectar production of 44, 16 and 18 pear cultivars, respectively, in a cultivar collection of pear during three consecutive years with highly different weather in the blooming. Results clearly show that pear does not necessarily produce small amount of nectar as stated in the world literature. In fact, pear can produce extremely high amount of nectar sometimes much higher than other temperate zone fruit trees species but its nectar production is highly subjected to weather, first of all to air temperature. Low nectar production seems to be more frequent than high one and cold weather can prevent its nectar production at all. On the other hand, results corroborate to the earlier statements on the low sugar concentration of pear nectar. There is a highly significant negative correlation between the amount of nectar produced by pear flowers and its sugar concentration (r = -0.52, n = 291, p< 0.001 for 1996, r = -0.34, n = 197, p< 0.001 for 1998). Sugar concentration in individual flowers may be up, to 40% in exceptional cases but generally it is well below 20%. Very high figures for sugar concentration in pear nectar at the literature seem to be incomprehensible. In contrast of some earlier statement in the literature no real difference could be established in the nectar production of pear cultivars, based on much more measurements than in earlier studies. Very low sugar concentration in pear nectar can explain the fact that the overwhelming majority of honeybees are pollen gatherers at pear trees even in the case of exceptionally high nectar production.

     

  • Studies on the essential oil of different fennel (Foeniculum vulgare Mill.) populations during onthogeny
    27-30.
    Views:
    228

    In the recent studies two Foeniculum vulgare Mill. populations (Hungarian and Korean) had been studied in open field trials in 1997-98 in Budapest for the identification of their essential oil characteristics. The essential oil accumulation level as well as the composition of the oil were studied during ontogenesis and at 6 phases of the umbel development from budding to overripening.

    In the vegetative phases, the accumulation level of the essential oil was higher in the Hungarian genotype. In the leaf rosette stage, anethole is the main compound in both genotypes (40-96%), except the root of the Korean populations which contains 54% dillapiol. The accumulation level of anethole is slightly decreasing, while dillapiol is slightly increasing during the ontogeny. a- and [3-pinenes are characteristic compounds of the leaves, especially in the Korean genotype (10-11%). Before seed setting, fenchone was present in a considerable amount (7.5%) only in the umbels of the Hungarian genotype.

    During the generative development, the maximum values of essential oil content are reached at the milky fruit stage (10,11%) in the Hungarian. and at the green fruit stage (7.1% ) in the Korean type, while the composition of the essential oil changed only slightly. The ratio of fenchone is increasing after flowering and being stable during ripening. Anethole varies to a smaller extent in the umbels, only.

    We proved, that the dinamics of essential oil accumulation and the oil composition may vary according to genotype. Based on our results, the Korean population is characterized in the system of Bernáth et al. (2) as a high anethol-low methyl chavicol chemoform of the anethol chemovariety (fenchone<15%; anethole>68%; methyl chavicol< 3,2%).

     

  • Partial and total rejuvenation pruning of sour cherry trees
    11-15.
    Views:
    322

    Sour cherry can be considered as a special fruit species regarding the growing characteristics, as most of the cultivars are characterized by strong balding. With the aging of the tree the inactive (passive) parts of the canopy are increasing steadily, so the productive cropping surface and the yielding capacity decrease  significantly. In our experiments partial rejuvenation pruning was carried out in a 12 years old orchard, and total rejuvenation pruning was performed in a 21 years old plantation to regenerate the cropping surface of the trees. Thanks to the latter one the canopy of the sour cherry trees were regenerated during only two years. The yields of the rejuvenated trees in cv. ‘Debreceni bőtermő’ exceeded the yields of the control trees, as in the case of the cvs. ‘Érdi bőtermő’ and ‘Újfehértói fürtös’ approached it. At the same time the total rejuvenation pruning has a positive effect on the fruit size.

  • Comparison of Xanthomonas arboricola pv. juglandis isolates from walnut trees grown in Romania and Hungary
    65-69.
    Views:
    286

    Among diseases that affect walnut, bacterial blight is considered the most important one in all walnut growing areas both from Hungary and Romania. For the determination of susceptibility/resistance of walnut cultivars in our posterior work planned, 61 bacterial isolates were collected from walnuts showing symptoms of blight, with the purpose of isolating Xanthomonas arboricola pv. juglandis (Xaj). The characteristic Xaj colonies, frequently present as saprophytes in the infected plant tissues, were separated from other bacteria according to their morphology, yellow colour, hydrolysis of starch, and oxidation of glucose. All isolates were tested for pathogenicity by hypersensitive reaction on tobacco leaves (Nicotiana tabacum L.), bean pods (Phaseolus vulgaris L) and unripe nuts (Juglans regia L.). Determination of taxonomy of the selected isolates denotes a possible subdivision (races, biotypes) of Xaj occurring in different geographical areas, API 20NE and API 50CH kits were used. Hungarian and Romanian strains showed a high degree of similarity of carbohydrate utilization but slightly differed from the type strain. All were Cu-sensitive.

  • Preliminary characterization of the self-incompatibility genotypes of European plum (Prunus domestica L.) cultivars
    23-26.
    Views:
    236

    European plum is an important fruit crop with complex, hexaploid genome of unknown origin. The characterization of the selfincompatibility (S) locus of 16 European plum cultivars was carried out using the PaConsI-F primer in combination with the EM-PC1consRD primer for the first intron and the EM-PC2consFD and EM-PC3consRD primers for the second intron amplification. Altogether, 18 different alleles were scored indicating high genetic diversity. These alleles were labelled using alphabetical codes from SA to SS. We  identified 5 different alleles in 9 cultivars, 4 alleles in 5 cultivars, while 3 alleles were shown in two of the assayed cultivars. A total of 16 different S-genotypes were assigned, and discrimination of all plum cultivars was successful based on their unique S-genotypes. However, further research is required to reliably identify the S-alleles based on their DNA sequence and clarify complete S-genotypes.

  • Flower density and winter damage of apricot and peach varieties
    53-56.
    Views:
    291

    Hungary is located on the northern boundary of economical apricot and peach production. The present assortment of varieties and the actual, not adequately selected growing sites cause a permanent risk of winter and spring frosts in their cultivation. The field observations are performed at Debrecen, the Experiment Station Pallag, on 20 apricot and 21 peach varieties. The flower density among the varieties attained 3-4-fold differences. Three categories have been suggested for both species. The density was inferior in Hungary established varieties compared with the new varieties of foreign origin. The minimum temperatures of January 9, 2009 was –17,6 °C , and of December 21, 2009 also –17,6 °C. In some varieties the damage of buds attained 100%. For estimating the yield security, we need to consider also the flower density and the frost damage together. For a mediocre yield, we need a flower density in both species of at least 0.2 living bud/cm. The results confirm the statement that in Hungary, the revision of growing sites is indispensable in order to develop a profitable and competitive apricot and peach growing industry.

  • The founding father of biotechnology: Károly (Karl) Ereky
    9-12.
    Views:
    3531

    Nowdays it is generally expressed opinion of the leading scientific circles that the purposefully planned biotechnological actions of the 21st century will be indispensable of realizing the sustainable technical development in the supplementation of the increasing population, especially those who suffer privation, thus the long-distance interests of mankind will be met without impairing the world's ecological integrity. In 1989 Robert Bud gave account of the fact that the father of the term "biotechnology" was the Hungarian agricultural engineer, Karl Ereky. Recently, we have explored and found some important biographical sources and scientific documents which had been published by Károly (Karl) Ereky, the which, however, have already been forgotten. This article expands on that more contextual treatment to explore the man and his doctrine. It draws upon Hungarian and private sources as well as on German publications.

  • The effect of Regalis® (prohexadione calcium) on the reduction of fire blight (Erwinia amylovora) severity in apple trees
    61-66.
    Views:
    202

    Due to the lack of effective and non-phytotoxic materials for control of the blossom and shoot blight phase of fire blight in pome fruit trees, two novel control strategies have emerged: shoot growth retardation by bioregulators and applying resistance inducer compounds. Prohexadione calcium (ProCa) is the active ingredient of the bioregulator Regalis® registered in several European countries. The reduction of shoot growth elongation is the most obvious effect of ProCa. Furthermore, it causes significant changes in the spectrum of flavonoids and their phenolic precursors, leading to the considerable reduction of susceptibility to fire blight.

    In Poland, potted one-year-old apple trees of cvs. Gala Must grafted on M.26 and Sampion on M.9 (in 2001) as well as Gala Must on P.60 (in 2002) were treated with Regalis® at a range of concentration of 250, 150 or 150 + 100 ppm, respectively. The inoculation of shoots was made with the strain No.691 of E. amylovora (107 cfu/ml), on the 7th and 21st'day after treatments with Regalis. In Hungary, during the years of 2002 and 2003 one-year-old container grown apple trees of the cvs. Idared/M.9 and Freedom/M.9 were treated with the prohexadione-Ca, the active ingredient of Regalis® 100, 150 or 200 ppm, two weeks before inoculation with the Ea 1 strain of E. amylovora (107 cfu/m1).

    In Poland, the suppression of fire blight in shoots reached up to 80%, depending on concentration and application time of Regalis®. In Hungary, the effect of prohexadione-Ca treatments, determined by the length of necrotic lesion developed, proved to be better than that of streptomycin used for comparison.

  • Increment analysis in black locust (Robinia pseudoacacia L.) stand – a case study
    106-109
    Views:
    289

    The study on the diameter and volume increment of black locust (Robinia pseudoacacia L.) stand (age 10-27 years, yield class II) have shown that in comparison to the periodic annual increment of the breast height diameter of tree in height class I, trees in height class II have reached 83.3%, while in class III only 43.9. The same relations for volume were found 59.0% and 24.5%, respectively. The mean values of the whole stand were close to those of height class II. According to the distribution of the periodic annual increment of volume between 10 and 27 years of age, 50% of the values were between 2.00 and13.88 dm3, 73% were between 2.00 and19.82 dm3, and 96% were between 2.00 and 37.64 dm3. The range of 13.88–19.82 dm3 had the highest occurrence (24.5%).

  • Pilot study for irrigation modelling of a pear plantation
    81-84.
    Views:
    368

    Our investigation was carried out in the area of Fruit growing Research and Consultant non-profit company, at Újfehértó. The pear requires large water quantity, but this pear plantation hasn’t irrigation system not yet. This study reviews the drainage conditions of the area based on digital elevation model, and examined the canopy cover of pear trees by evaluating of the hyperspectral image. Our aims were to determine the exact watershed based irrigation modelling and determining of the canopy% of the pear orchard to facilitate a precision irrigation decision support system.

  • The relationship of the plant protection and the applied technology in the integrated apple production
    11-14.
    Views:
    304

    The indirect elements of the integrated plant protection can infl uence the effectiveness of the chemical control, however their significance are often extenuated. The characteristic of the plants are almost completely disregarded at the protection decisions. The condition can determinate basically the rate of the damages caused by the pests. The plant in good conditional state has higher tolerance and lower susceptibility against the pests. With the optimal general and annual condition we can establish and maintain the harmony between the growth and the bearing, what is the basis of effective plant protection.

  • Sour cherry for fresh consumption in the retail sector A consumer aspect
    81-84.
    Views:
    195

    The basic objective of our study is the promotion of fresh consumption of sour cherry and the enhancement of necessary knowledge. Primer collection of data was planned in three groups of retail shops, always sour cherry being the matter of study. The sampling dates were adapted to the sour cherry season weeks in Hungary. Three samples per week have been taken. Every time a short interview and purchase was planned. Every time, it was stated that the commodity was held for a longer period on the shelf, which trespasses the optimum of the fruit. At the same time there was no concordance between quality and price. From the point of view of the consumer this cannot be accepted.

  • Anatomical relations of root formation in strawberry
    71-75.
    Views:
    211

    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.

  • Obtention of new ornamental leaf variants of giant reed (Arundo donax L.) originated from somatic embryogenesis and their photosynthetic parameters
    18-24.
    Views:
    457

    Giant reed (Arundo donax L.) is a perennial rhizomatous herbaceous plant, it has been widespread all over the world by human activities. It is a 2-8 meter high, polyploid, sterile species (not produce viable seeds), it can be propagated only by vegetative methods (rhizomes, stem cuttings, in vitro biotechnological methods). It has considered promising dedicated energy crop thanks to high biomass production (20-40 dry tons per hectare depending on microclimate), adaptability of different kind of soils and environment and low energy input required for its cultivation. It has been utilized for energetic purposes, biogas/bioethanol production, cellulose/paper production and ornamental purposes. The objectives of the present study were to determine morphological properties of new ornamental giant reed leaf variants originated from somatic embryogenesis and to evaluate their photosynthetic pigment content and photosynthetic activities. The most typical changes was the appearance of different colour (white, yellow, light green) longitudinal stripes on leaves (also on petiole and on leaf blade). It was significant differences (p<0.05) between green and leaf variants in case of photosynthetic pigments content and photosynthetic activity (Fv/Fm value). There was no detectable chlorophyll a or b content in the white bands of leaves and albino shoots. Total chlorophyll content of the white striped leaf variety was more than twice than the light green leaves. Photosynthetic activity and content of photosynthetic pigments also confirm and determine the morphological characteristics and growth habit of leaf variants.

  • Growing characteristics of apple cultivars in environmentally friendly growing systems
    7-10.
    Views:
    255

    Nowadays the condition of the good saleability of the fruit is the application of controlled environmentally friendly technologies. Success of the growing is basically influenced by the production value of the cultivars, and their flexibility to the different technologies. In our examinations the effect of the integrated and organic farming  system has been evaluated on the growing characteristics of the apple cultivars. According to our results the trunk thickness of the trees both in the initial and both in the later bearing period is higher in the integratedproduction compared to the organic farming system. This differences most likely caused by the variance of the crop load.