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Bioactive phenols in leaves of Forsythia species
57-59.Views:217Nowadays 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.
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Apple powdery mildew caused by Podosphaera leucotricha: some aspects of biology
19-23.Views:348Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. Biology of the pathogen is widely investigated all over the world in the past 100 years. In this review, a summary from this enormous research is made for biology of apple powdery mildew in the following aspects: geographical distribution, morphology, taxonomy of the causal agent, symptoms, host susceptibility, resistance durability and disease cycle.
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Certification programme for production of virus-free propagating material of grapevine and its results in Hungary
39-43.Views:139In Hungary, detection of virus and virus-like diseases of grapevine began in 1960's at the Research Institute for Viticulture and Enology by János Lehoczky and his colleagues. At present, sixteen virus and virus-like diseases of Vitis vinifera are known to occur in Hungary.
Regular virological screening of grapevine varieties started in 1972. The present system of screening (visual selection, indexing, ELISA) has been established using methods with continuous improvement according to recommendations of international organizations.
In the first year symptomless grapevine plants are selected and marked during surveys carried out twice in the vegetation period: at about flowering and in the second half of September. At the first selection time plants are sampled for ELISA.
In the spring of the second year, overwintered canes are checked by woody indexing on 8 indicator species in the field.
In the third and fourth years the nursery is evaluated twice again. At the end, the marked grapevine plants, giving negative results on all indicators in every case, are considered virus-free.
In autumn of the fourth year, the virus-free material is planted out under screenhouse and also in a special mother block (nuclear stock) for maintenance and propagation.
Mother blocks of virus-free scion varieties have been established on 2 ha and those of rootstock varieties on 0.5 ha planted with the following number of varieties included in the national list: 71 European scion — and 12 rootstock varieties or variety candidates/clones. It is necessary to increase the area of Pre-base, Base and Certified stocks exclusively with tested virus-free (clean) material.
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Flavonoids, chalcones and phenyl-propanoids in apple and pear flowers
35-38.Views:138The presence of phloretin-glycosides in the hypanthium and pistil of apple and pear flowers can be verified. Thin layer chromatography is a reliable method for detecting phloretin, gained by acidic hydrolysis. The dominance of phloretin was equally characteristic for flowers in apple (`Sampion', 'Freedom') and pear (Tem-re Bosc', 'Conference') cultivars treated with various bioregulators (Biomit, Bion 50WG, Regalis), no significant difference could be found visually as compared to control samples. Chlorogenic acid and caffeic acid was detected in all apple and pear samples, rutin was present only in pear, and hyperoside was found only in a few apple samples.
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Floral biology of hazelnut (Review article)
7-19.Views:211Floral biology of hazelnut (Review article)
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Transformation of tobacco plants with virEl gene derived from Agrobacterium tumefaciens pTiA6 and its effect on crown gall tumor formation
53-56.Views:137The VirEl protein plays a key role in the transport of VirE2 protein from the bacterium to the plant cell during crown gall tumor induction by Agrobacterium. The virEl gene of A. tutnefaciens pTiA6 was cloned into the plant transformation vector pTd33 yielding pTd93virEl that was introduced into A. tuniefaciens EHA101 and used for tobacco transformation. The presence of the foreign DNA in the putative transgenic plants was confirmed by PCR analysis. Nine of the 41 transformed plants formed only small tumors following infection with the wild-type A. vitis octopine strain AB3. This property was inherited into the T1 generation. The expression of virEl gene in TI plants was demonstrated by Northern blot analysis.
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Reproductive biology of Duranta repens L. (Verbenaceae) in relation to its environment
51-55.Views:218Impact of environmental changes (temperature and RH) on reproductive biology in Duranta repens (Verbenaceae) growing at ten different sites of Agra was studied. It flowers throughout the year, with optimum flowering in September. The flowers are arranged in loose clusters on terminal or axillary racemes. They are either blue or lavender in colour, hermaphrodite, actinomorphic and complete. The plants exhibit floral polymorphism (increase and decrease in number of petals and stamens) and considerable variation in extent of pollen fertility, floral density, insect pollinators and fruit-set percentage. The changes in temperature and relative humidity during the entire flowering period, was found associated with the variation in floral structure, pollen fertility and fruit-set percentage. Based on the percentage of fruit-set during different seasons of a year, there were three distinct periods, namely maximum, moderate and minimum periods. The present paper deals with the comparative view of reproductive biology of this ornamental plant in these periods. During the months of August—November when temperature ranges between 13.7-36.6 °C and RH between 79-89% the plant exhibits maximum fruit-set percentage (68-85%). This was associated with maximum flowering, increase in floral size, and increase in visitation rates of pollinators and higher degree of pollen fertility. On the other hand, with temperature reaching to the maximum (15.1-41.5 °C) and reduction in RH (14.1-41.3%), the percentage of fruit-set was reduced to the minimum (21-30%). During this period, number of flowers/plant, floral size, pollen fertility, visitation rates of pollinators were reduced to the minimum. During this period floral polymorphism was also 'recorded.
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Floral biology of tree fruit rootstocks
153-161.Views:152The modern nursery industry requires seed sources of a high quality and regular quantity year by year. Besides the seed sources of processed cultivars (Bartlett pear, Shipley, Elberta peach) special seed orchards are planted with selected seed trees producing high quality and genetically determined seed (hybrid seed or inbred lines). Seedlings are still the most common commercial source of rootstocks for stone fruits (almond, apricot, peach, plum, prune and walnut). Although clonal rootstocks are spreading, usage of seedlings is still predominant at stone fruits and nuts. For successful seed production and planning of seed orchard the knowledge on floral biology, flower fertility, pollination, blossom time of trees (selected clone or cultivars) used for seed production is essential. In this field very little systematic research was carried out most of the papers were published in the second half of the 20th century. Our mini review gives an overview on the importance of flower fertility in the mating systems applied in seed orchards, and the research results on floral biology of fruit tree rootstocks propagated by seed (Prunus avium, Prunus mahaleb, Prunus armeniaca, Prunus cerasifera, Prunus insititia, Prunus amygdalus, P persica, P amygdalopersica, Pyrus pyraster, Pyrus communis and Pyrus betulifolia) over the last decades.
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Pál Maliga, founder of the research in floral biology of fruit species in Hungary
57-60.Views:144Pál Maliga founded the Hungarian research in floral biology of fruit species during his more than forty-year-long carrier. Almost all pome and stone fruit species have been covered by his activities, but he also dealt with the fertility of walnut and chestnut. Regularities have been revealed and the methodical studies opened the way to approach and elaborate alternatives for the association of varieties in planning high yielding commercial plantations. In his breeding activity the choice of crossing parental varieties was based on the knowledge in fertility relations. The obtained sour cherry varieties represent the world-wide maximum quality, reliability and security of yields. Hungarian renewed sour cherry cultivation owes its fame and prosperity to those varieties, nevertheless also to the radical knowledge of the biological bases of fertility.
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Apple powdery mildew caused by Podosphaera leucotricha: some important features of biology and epidemiology
45-51.Views:340In this review, some important features of biology and epidemiology are summarised for apple powdery mildew (Podosphaera leucotricha). In the first part of the review, the geographical distribution or the pathogen are discussed, then the morphology and taxonomy of the causal organism are described. Disease symptoms or apple powdery mildew are also shown and then host susceptibility/resistance is discussed in relation to durability of resistance. In the second part of this review, the general disease cycle of powdery mildew on apple are demonstrated and some basic features of powdery mildew epidemiology (such response of the pathogen to temperature, relative humidity, and rain as well as spore production, spore dispersal, diurnal patterns and temporal dynamics of the pathogen/disease) are also given on apple host.
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Floral biology and fertility in peaches (Review article)
9-14.Views:159Floral biology and fertility in peaches (Review article)
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Investigation of the in vitro regeneration of mericlones in the caribe variety of carnation
87-89.Views:130In vitro culture conditions were experimented for the relatively sensitive, but very esthaetic "Caribe" variety of carnation with uniformly dark violet flowers. Regeneration of new plants from shoot apex meristems can be significantly improved by the combined addition of very low amounts of indolebutiric acid, benzyladenine and gibberelic acid, dissolved in the Murashige-Skoog nutrient medium. Callus formation as a prerequisite for the induction of somaclonal variability can be achieved successfully with certain molar ratios between 2,4-dichlorophenoxyacetic acid and benzyladenine. Acclimation of the obtained mericlones to the ex vitro conditions was also evaluated.
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Carbohydrate utilization of Erwinia amylovora in vitro
31-34.Views:153Nectar is a multi-component aqueous solution that promotes bacterial multiplication. The concentration of nectar in plant flowers is not stable since it is under the influence of environmental conditions, especially free moisture and relative humidity. Experiments were conducted with "artificial nectar" and directed along two lines: (1) determination of the optimal concentrations of carbohydrates for the growth of E. amylovora development (2) consumption of different carbohydrates besides basic sugars.
Solutions of "artificial nectar" were prepared in different compositions by changing the dominance of basic sugars (fructose — glucose —sucrose) in proportions of 2:1:1, 1:2:1, 1:1:2 and between concentrations of 10-0.6% (diluted with Basal minimum broth) in order to determine optimal conditions for the development of E. amylovora.
At a basic sugar concentration of 10% bacterial multiplication started and continued until I log degree (from 106 to 107 cfu/ml). At concentrations of 5% and 2,5 % cells developed with nearly the same kinetics (from 106 to 8x107 cfu/ml and from 106 to 9x107 cfu/ml, respectively). Multiplication was more pronounced and nearly the same at concentrations of 1.2 % and 0.6 % (from106 to 2x108 cfu/ml). At a basic sugar concentration 30% total sugars bacterial multiplication did not occur, while at 20 % it was negligible, not measurable photometrically.
At minimal concentrations of F, G, S (between 1-0.1 %) bacterial cells were still able to multiply, producing organic acids from sugars.
Our study showed that E. amylovora requires only a small amount of sugars (0.1%) for multiplication (acid production) while high concentrations inhibit multiplication. There was a negative correlation between sugar content and cell density. The optimal range of sugar concentration was at about 1%.
Effect of "less frequent carbohydrates" to E. amylovora multiplication was also determined using the API 50 CH strip. We could provide information on utilization of 39 carbohydrates by the bacterium at different categories as follows: Not utilized-, Slowly and weakly utilized-, Slowly and completely utilized-, Quickly and completely utilized carbohydrates. We suppose that carbohydrates that belong to the latter two groups could play an important role as nectar components in promoting E. amylovora multiplication in the blossoms of pome fruit trees.
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Floral biology of medicinal plants II. Lamiaceae species
137-140.Views:291Several species in the Lamiaceae family are therapeutically significant medicinal plants. Such as sage (Salvia officinalis L.), rosemary (Rosmarinus officinalis L.), peppermint (Moldier piperita L.). marjoram (Majomna hortensis Winch), thyme (Thymus vulgaris L.), Origanum spp., hyssop (Hyssopus officinalis L.), Lavandula spp., basil (Ocimum basalicum L.), lemon-balm (Melissa officinalis L.) are regularly produced in Hungary. Nevertheless, data on their floral biology are not satisfactory. This review intends to gather information on the characteristic constitution of flowers and inflorescences, blooming dynamics, pollination mechanism and crossability of some of the most significant medicinal and spice species
Flowers are mainly hermaphrodite, however, also monoeceous ones are turning up: pistillate flowers marjoram, tyme, oregano. In flowering of a plant individual, a basipetal blooming sequence is described. These species have a floral structure fully adapted to pollination by insects, and the majority of them is an excellent honey-plant (lavandel, hyssop, sage, etc.).
Flowers exhibit characteristic proterandry, therefore autogamy is considered to be almost impossible, and geintonogamy as well as xenogamy to be the most characteristic ways of fertilization. However, in several cases self-fertilization proved to be also successful. Crossability among cultivars or species is depending on the genotype combination and usually produces less seed than the above forms of fertilization.
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Fruit drop: II. Biological background of flower and fruit drop
103-108.Views:294The 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.
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Floral biological studies on pear cultivars in relation to fire blight susceptibility
25-30.Views:150Floral 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.
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Comparative study of sour cherry samples for their anthocyanin content measured by tools of the laboratory and by portable equipments
29-31.Views:247The inner quality of fruits depends on many components. The analysis of pharmacologically important fruit species as the sour cherry consumed as a common food is an expensive task, mostly requiring an equipped laboratory. In sour cherry, one of its valuable components, the anthocyanin content deserves special attention. A portable analytical implement, which has been developed by our team measures the anthocyanin content on a scale of 1024 PharMgrades. The system is a member of the UVEX family of implements working with a microprocessor and performs the measurement quickly. The portable variant (UVEX-ML-1) does not require much training, the laboratory variant (UVEX UL-1) performs a large quantity of tests under modest laboratory conditions. Preparation of the samples is easily done, the necessary elements are available in the trade. The reagent is easily stored and dosed. The system was tested and proved to be of sufficient precision and the result showed acceptable variance according to the checks performed by a spectrophotometer in the laboratory.
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Floral biology of medicinal plants I. Apiaceae species
133-136.Views:381The Apiaceae family consists of several species which are well known for their therapeutical use and also as spice plants. Although fennel (Foeniculum vulgare Mill.), caraway (Carton carvi L.), anise (Pimpinella anisum L.), coriander (Coriandrum sativum L.), dill (Anethum graveolens L.), angelica (Angelica archangelica L.) and lovage (Levisticum officinale Koch.) are also economically considerable cultures, data on their flowering biology are rather scarce. This review supports data on the characteristic constitution of flowers and inflorescences, flowering dynamics, pollination mechanism and crossability of some of the most significant medicinal and spice species.
The inflorescence is a compound umbel. Flowers are hermaphrodite, however also monoeceous, mainly male flowers are turning up too. In blooming of a plant individual, a strict sequence is observed. The main umbel is the first to bloom, followed by the different range umbels in order of their range. In their pollination, both wind and insects are considered to be active. For each species, proterandry is characteristic. Although autogamy is considered to be almost unpossible, and geintonogamy as well as xenogamy to be the most characteristic ways of fertilization, several cases of self-fertilization proved to be also successful. Crossability among cultivars or species is depending on the genotype combination and usually produces less seed set than the above forms of fertiliiation.
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Effect of hydroponic and peat-free media in transplant production of Rudbeckia hirta varieties under different photoperiodic lighting and their photosynthetic parameters
110-117Views:367The purpose of this research was to determine the effects of varieties, different light conditions (short day, long day, natural short day with light pollution), and different growing media (perlite, peat-free, peat-based, aeroponics system) on Rudbeckia hirta plant production under controlled conditions (greenhouse). The morphological effects of each treatment (photoperiodic lightings and media) on different Rudbeckia varieties determined at 11 weeks-old ’Napfény’, ’Toto Gold’, ’Autumn Colors’, ’Prairie Sun’ and 16 weeks-old ’Napfény’. Plantlets received 12 hours daylight did not initiate flowers, remained stage of the leaf rosette in case of all varieties. The 14 hours light treatment in the aeroponics system and the same treatment in perlite and control (natural short day with 14 hours light pollution) plantlets had developed inflorescences or flower buds. The inflorescence axis of ‘Napfény’ was appeared at 13 weeks under long-day conditions, with 1.7 (perlite) - 2.7 (aeroponics) flower buds in 16 weeks. ’Toto Gold’, ’Autumn Colors’, ’Prairie Sun’ varieties developed inflorescences at 8 weeks, 14 hours aeroponics system resulted in the most of flower buds (’Toto Gold’: 6.5, ’Autumn Colors’: 3.25,’Prairie Sun’: 4.8 flower buds) at 11 weeks. Long daylight manipulation could be minimized crop times and achieved flowering potted plants at 11 weeks. The peat-based and peat-free media effect was observed on ‘Autumn Colors’. The number of leaves of peat-free ‘Autumn Colors’ transplants (16.8-20.3) was significantly higher than peat-based media (13.5-15.5). Other morphological parameters were not affected by the media treatments.
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Brown rot blossom blight of pome and stone fruits: symptom, disease cycle, host resistance, and biological control
15-21.Views:823In this paper, important features of symptoms, biology and biological disease management are summarised for brown rot blossom blight fungi of pome and stone fruit crops (Monilinia laxa, Monilinia fructicola and Monilinia mali). Firstly, European brown rot caused by Monilinia laxa is discussed highlighting the blossom epidemiology features, then host susceptibility of the most important stone fruit species including several Hungarian and international cultivars. At the end of this chapter, recent biological control possibilities against Monilinia laxa are also included. Secondly, American brown rot caused by Monilinia fructicola is discussed. Symptoms, biological features of blossom blight and host susceptibility of flowers to Monilinia fructicola are demonstrated. Finally, the symptoms and the biology of the least frequent species, Monilinia mali are shown.
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The brown rot fungi of fruit crops (Monilinia spp.): I. Important features of their biology (Review paper)
23-36.Views:185The brown rot fungi of fruit crops (Monilinia spp.): Important features of their biology (Review paper)
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Dr. Ottó Orsós, the forgotten Hungarian pioneer in plant tissue culture
9-13.Views:161The knowledge of tissue culture deserves attention in respect of understanding the development of universal biology. This study intends to contribute to the past of the plant tissue culture by such data of the history of science which have been unprocessed so far. It seems that the life-work of the Hungarian biologist, Dr. Ottó Orsós is a missing and essential link between those early plant hormone researchers and the representatives of the pioneers of tissue culture schools who have contributed substantially to the development of the modern in vitro plant morphogenesis and plant cell biology. Orsós cultured kohlrabi tuber cubes on White culture medium in a sterile manner. This way, he could efficiently direct the in vitro morphogenesis of the kohlrabi, the regeneration of its shoot and root, and the formation and steps to subculture of pure callus tissues in 1938. He supported the correctness of its statements by means of detailed anatomical examinations. Orsós successfully rooted and aclimatized complete regenerated plants. We may as well call the above system — in remembrance of the creators of the original concept — "Haberlandt-Orsós model". Between the publishing of his main paper in 1938 and 2003, a period of 65 years has lapsed. On the occasion of this anniversary, we bow before this forgotten pioneer.
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Seed protectant potential of Mitracarpus villosus and Phyllanthus fraternus extracts on germinative capability of stored food grains
7-10.Views:322Seed storage is an essential post-harvest operation that decides the success of seeds viability and germination in next generation. The study explored Mitracarpus villosus and Phyllanthus fraternus extracts as bio-insecticides seed treatments on stored wheat and green gram seeds viability and germination. M. villosus and P. fraternus plants powder were sequentially extracted with solvents of increasing polarity (Petroleum ether, hexane, ethyl acetate, acetone, chloroform and methanol), concentrated and tested for insecticidal activity by fumigant toxicity. The extract which showed maximum activity, was selected for seed viability and germination test. Five replications each were made for the treatment and the control. The plant extracts strengthen the non-phytotoxic nature of plant products against seed viability and germination. Seeds treated with extracts (50-400 μg seed-1) did not lose their viability as it resulted in successful and normal germination within the range of 90 – 97.67% irrespective of the extracts concentration. While, seeds in control recorded 95.55 and 100% germination which were not significantly different (P>0.05) compared to the treated seeds. Based on findings from the study, potential exploitation of M. villosus and P. fraternus as food grains protectant in insect pest management strategies is recommended for the resource poor farmers. However, further investigations are suggested on biosafety and effects of the extracts on the organoleptic contents of the grains prior to consumption.