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Ultrastructural and biochemical aspects of normal and hyperhydric eucalypt
61-69.Views:211Hyperhydricity was observed throughout in vitro multiplication phase of a Eucalyptus grandis clone. Ultrastructural approach of tissue and cell differentiation, izoenzyme patterns, binding protein (BiP) expression, and pigment content were performed. Hyperhydric tissues showed a reduction in cell wall deposition, reduction of membranous organelles, higher cell vacuolation, and more intercellular spaces than its normal counterpart. Additionally, several vesicles were present in hyperhydric cells suggesting the occurrence of organelle autophagy by autophagic vacuole. Lower pigment content, intercellular spaces on the epidermis and the induction of a molecular chaperone (BiP) were observed in hyperhydric phenotype. Evidences of schizolysigenous process of intercellular space formation are compatible with a stress condition. Although plastoglobulli were observed in normal and hyperhydric chloroplasts, they were more evident in the normal ones. Abnormal stomata also reflected a disruptive situation and morphogenesis disturbances which would difficult plant acclimatization. Further observation of the epidermis ultrastructure allows us to conclude that the presence of intercellular spaces on its surface may be constraining the recovery and development of hyperhydric plants. Similarly to BiP, other proteins such as esterase (EST), acid phosphatase (ACP), malate dehydrogenase (MDH) and peroxidase (PDX) are possible to be used as stress markers in in vitro conditions. Our results confirm earlier findings about negative effects of hyperhydricity on in vitro plant morphogenesis and ultrastructure, which in eucalypt is associated with a stressful condition contributing to lower propagation ratios.
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Effects of indole-3-butyric acid levels and activated charcoal on rooting of in vitro shoots of apple rootstocks
25-28.Views:249Rooting responses of rootstocks cvs. JTE-F1, M. 26 and MM. 106 were studied to different concentration of IBA in root induction media and to presence of activated charcoal in root elongation media. High rooting rate (>90%) could be achieved in cvs. JTE-H and M. 26, while cv. MM. 106 showed weak rooting ability at each IBA level tested. Increasing IBA content depressed the rooting only in cv. M. 26. Presence of activated charcoal decreased considerable the rooting rate in cv. M. 26 and decreased the number of roots in cvs. JTE-H and M. 26. These cultivars developed longer roots on media containing activated charcoal, while cv. MM. 106 did not showed any reaction for it.
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Maceration affects mineral composition and pH of wines
25-29.Views:240Mineral composition of wines is affected by many ecological and technological factors. These variables are mostly discussed focusing on certification of origin and human health. This paper gives data on possible changes in mineral composition and pH of wines due to 4 hours skin maceration (1st trial) and fermentation sur marc (2nd trial). Experimental site is situated on acidic sandy soil in middle east Hungary. The variety collection was established in 2003 with own rooted planting material in 3x1 m spacing, trained for single curtain training
system. Mineral composition of wines was determined with ThermoFischer Scientific iCAP 6300 ICP-OES, pH was measured with pH10pen (VWR International) in field, and with SevenEasyTM pH meter (Mettler Toledo) in laboratory. 1st trial with 9 PIWI white wine grape varieties pointed to demonstrate effects of skin maceration, which is abundantly used to elevate aroma content. 2nd trial with the use of ‘Medina’ red PIWI grape variety aimed to demonstrate effects of double pasta skin maceration in rose and red wine technology. Data of 1st trial show, that K, Cu, Mn and P respective increase with skin maceration, despite Fe show considerable decrease. Data of 2nd trial show, that K, Mg, Mn, P, Sr and B increase with longer skin contact and higher fermentation temperature, despite Fe and Ba decrease with this technology. In regard to pH, data show, that skin maceration and fermentation sur marc increase K content with about 30-70% respectively, withstanding that pH also increase with a considerable 0,4-0,5 value. K content can be higher in the end product, despite to earlier higher level of tartrate formation. An attention should be driven to lower level of tartaric acid and consequently higher pH characteristic for wines produced with the application of skin maceration or fermentation sur marc. -
Effects of self and cross pollination on fruit set and fruit quality of sour cherry cultivars
31-36.Views:284An experiment conducted using factorial based on randomized completely block design during 2005 and 2006. Flowers of Érdi bőtermő, Érdi jubileum and Cigány meggy before anthesis and in balloon stages were isolated with paper bags from guest pollens and pollinated in appropriate time. The averages of final fruit set showed the advantage of open pollination (14.6% fruit set) in compare with artificial self pollination (13.0% fruit set) and natural self pollination (4.4% fruit set). Siah mashhad sweet cherry cultivar with more than 70% overlap of flowering and 9.8% fruit set in 2005 and 17.9% in 2006 was the best among applied pollinisers for Érdi bôtermô sour cherry cultivar.Also, Siah mashhad sweet cherry with more than 50%overlap of flowering time and 25.8%fruit set was the best polliniser for Cigány megg. Among the pollinisers, Siah mashhad was the best for Érdi jubileum with more than 50% overlap and 15.22% fruit set. Meanwhile, pollens of Siah mashhad caused the increase of fruit size in Cigány meggy cultivar. phenomenon. Pollens of Siah mashhad caused reduction in total soluble solids of Érdi bôtermô fruits, however, it does not have any significant effect on the acid rate of fruits.
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Results with the establishment of in vitro culture of Leucojum aestivum
67-71.Views:217Leucojum aestivum is a native, protected ornamental and medicinal plant in Hungary and in Ukraine too. The aim of our work was to establish in vitro cultures of this bulbous plant. Prior to surface sterilisation the old leaves and roots were dissected from the bulbs and they were stored in a refrigerator (2-3°C) for different periods (1 week for the first starting experiment and 5 weeks for the second one). After sterilisation, bulbs, bulb scales and leaves of the bulbs were placed on Murashige and Skoog's (1962) medium with 1 mg/1 benzyl-adenine (BA) and 0,1 mg/1 naphthalene acetic acid (NAA). At the first starting experiment 81,3%, and at the second one 92,3% of the explants turned to be sterile. Bulblets and roots were developed on the explants in the case of using bulb plates together with bulb scales and leaves as inoculua. The best result was achieved after 5 weeks chilling and it was possible to gain little bulbs from the bulb leaves too.
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Changes in germination ability during genebank storage at some medicinal plant seeds belonging to the Solanaceae family
51-55.Views:113In the present work we have examined the changes of germination ability of some medicinal plant species belonging to the Solanaceae family (Datura stramonium L., Datura innoxia Mill. and Hyoscyamus niger L.) during 5-6 years' storage period. According to our results, all the three species showed an after-ripening behavior. Potassium nitrate and gibberellic acid increased significantly the rate of germination in the case of Datura species. During the storage period tested (1995-2001), the species maintained their germination ability which is favourably but not significantly influenced by the cooled gene bank conditions. The degree of ripeness affected considerably the proportion of germinated seeds at all the three species. As a consequence of our results we emphasise that propagation with completely ripe seeds is proposed, however, half-ripe seeds developped in an unadvantageous vegetation period can be also utilized in the practice. The effect of vegetation year on stramony seeds manifested in the length of after-ripening period, while in the case of henbane the germination ability was also influenced.
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Role of hydrogen peroxide and Pharmaplant-turbo against cucumber powdery mildew fungus under organic and inorganic production
39-44.Views:410Cucumber leaves have been sprayed with a solution of hydrogen peroxide (H202) or Pharmaplant-turbo combined with organic or inorganic fertilizers under plasic house. Under the influence of H202, leaves exhibited resistant against Podoshaera fusca fungus, the causal agent of cucumber powdery mildew. H202 (15 mM) was able to decrease the disease severity from 90.4% to 12% in two experiments conducted in two seasons. Pharmaplant-turbo (Turbo) is new chemical compound and used as an antifungal compound. Turbo in 1 ml/L was able to decrease the disease severity from 90.4% to 11.5% in the both experiments as well. Both of H202 and Turbo were combined with organic treatment (compost + compost tea + seaweed extracts) which showed significant effect against cucumber powdery mildew fungus and strongly suppressed it as compared to control leaves. Organic treatment produced higher vegetative growth characters and greater early and total yields as compared to inorganic treatment, also organic fruits produced the lower nitrate content and the higher ascorbic acid content as compared to inorganic fruits. Our study have indicated that, H202 and Turbo combined with organic fertilizers play a role in the resistance of cucumber against powdery mildew by decreasing the disease severity. We suggest to give more attention to the direct application of H202 in low concentration and Turbo against powdery mildew diseases and other plant diseases.
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The effect of different cytokinins on chlorophyll content and morphological features of in vitro Nidularium ’Kertész Jubileum’
47-51.Views:227During in vitro multiplication of Nidularium ‘Kertész Jubileum’, 20 g/l sucrose, 5 g/l agar, 100 mg/l inositol, and different concentrations of benzyladenine (BA), benzyladenine-riboside (BAR), kinetin (KIN), meta-topolin (mT) were added to the MKC (Knudson, 1946) basal medium. Furthermore, 0.1 mg/l naphthaleneacetic acid was used to every medium. Number of shoots, length of leaves, number and length of roots, chlorophyll (a+b) content were examined and evaluated with Ropstat statistical software. As compared to the other cytokinin, significantly most shoots were obtained in the case of applying BA. Increasing of BA-concentration (as far as 2 mg/l) enhanced shoot number (from 10.92 to 19.26) but 4 mg/l BA resulted only 6.63 shoot. The less efficient cytokinin was KIN, in most cases no more than about 2 shoot was achieved. Regarding the length of leaves, the higher level of BA effected averagely the shorter leaves (from 24,46 to 7.31 mm). KIN effected significantly the longest leaves (43.4-61.29) in inverse proportion to the concentration. The same cytokinin resulted the most (and the longest) roots with the highest rooting percentages, but more KIN decreased the number and length of roots (from 7.95 to 4.4 and from 38.49 to 22.73 mm). There were no definite correlation between cytokinin concentration and chlorophyll (a+b) content, but the highest doses resulted decreasing (except of meta-topolin which leads to the lowest values). Summarizing, BAR effected the highest contents (mostly more than 1400 μg/g), particularly in the case of 1 mg/l (1807.3 μg/g).
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Comparative evaluation of different valerian (Valeriana officinalis L.) lines
63-66.Views:157Research project to establish a Hungarian valerian cultivar with acceptable production, biological and chemical properties of five promising Valeriana officinalis L. lines were studied. The populations were not homogeneous especially with regard to leaf shape and colour. Line 'IV/1' showed the strongest vigour, was characterised by the highest root-yield (381.79 g/plant), volatile-oil (0.60 m1/100 g) and valtrat content (1.15%). However, the highest valeric-acid content (0.20%) was measured in another line, 'I/5'. According to our results, the above-mentioned lines (1/5', 'IV/1') could be the basic material of breeding work in the future.
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Influence of antiobiotics on NAA- induced somatic embryogenesis in eggplant (Solanum melongena L. cv. Embil)
88-95.Views:156The influence of increasing concentrations of naphthaleneacetic acid and the antibiotics cefotaxime, timentin, kanamycin, and hygromycin on eggplant (Solantun melongena L. cv. Embil) somatic embryogenesis was investigated. Cotyledon explants were excised from 16 to 20 days old in vitro grown seedlings. NAA promoted somatic embryogenesis, although its concentrations had no influence on the mean number of embryos. Callusing decreaSed significantly with increasing NAA concentrations. Morphogenesis was stopped with 50 to 100 mg L-1 kanamycin and 7.5 to 15 mg L-1 hygromycin. Although early globular embryos were observed up to 15 mg L-1, further embryo development was inhibited at 10 mg L-1. Interestingly, cefotaxime (250 and 500 mg L-1) promoted a marked effect on enhancing fresh weight of calli, accompanied by decrease in embryo regeneration, whereas timentin concentrations (150 and 300 mg L-1) did not affect embryo differentiation as compared to the control treatment.
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Introduction of alkanet (Alkanna tinctoria (L.) Tausch), a traditional dye plant into cultivation
41-46.Views:275As a part of the research project to establish natural sources of plant pigments, possibilities of introduction of Alkanna tinctoria (alkanet) into cultivation were studied.
As a result of the germination experiment, the relevance of 21 days' duration of germination procedure was proved. To get high germination rate alkanet fruits are proposed to pretreat by gibberellinic acid (GA3) in the concentration of 400 ppm, overnight before sowing. This method results approximately 50 % germination rate.
The morphological and production properties of alkanet roots are characterized during ontogenesis. Transplanted populations can be characterized by numerous, thick and heavy roots comparing to the spontaneous ones. Thus, seed sowing and transplantation proved to be an effective method for cultivation of the species.
According to our results it can be concluded that in cultivation the optimal harvesting time of roots is at the end of the second vegetation cycle, when the dry root mass of the individuals is about 10-20 g with 3,0-3,5 % accumulation level of active substances.
Considerable seasonal variability have been found influencing not only the root masses, but also the accumulation levels of alkannin derivatives. In a more humid vegetation cycle the root size and mass as well as the content of active substances are much higher.
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Composition and storage of pear cultivars from Nagykanizsa
63-68.Views:214The composition of five pear varieties (‘Abate Fètel’, ‘Bosc’, ‘Williams’, ‘Conference’, ‘Packham’s Triumph’) grown in Nagykanizsa was investigated in three consecutive years (2008, 2009, 2010). A storage experiment was performed in 2008. Four winter pear cultivars were kept in an ULO store for four months and their parameters measured after two and four months. The parameters tested were: size, weight, water soluble solids, titratable acidity, glucose, fructose, sucrose, water soluble pectin, total polyphenols, free radical scavenging capacity, copper and zinc content. The fruits of ‘Conference’ and ‘Bosc’ varieties were found to contain the highest sucrose and total sugar content, while ‘Abate Fétel’ had the lowest sucrose and highest glucose levels among cultivars tested. ‘Williams’ pear was the most acidic. Brix, total sugar, sucrose and water soluble pectin were decreased during storage. Titratable acidity slightly decreased in fruits of Conference pear. Polyphenols and free radical scavenging capacity did not show a significant change during storage.
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Impact of boron foliar fertilization on annual fluctuation of B in sweet cherry leaves and fruit quality
27-30.Views:266The goal of the study was to examine response of sweet cherries (Prunus avium L.) to boron (B) fertilization. The experiment was conducted during 2005-2007 in West Hungary on mature cv. `Germersdorfi 3' grafted on Prunus mahaleb rootstock.
Sweet cherry trees planted on a calcareous chernozem soil. Trees were foliar-fertilized with B. Foliar B sprays were performed: (1) in the spring, at the stage of white bud, beginning of flowering (B1), and (2) repeated 5 weeks after full bloom (B2). In each of spring spray treatments, B was applied at a rate of 0.15 kg ha-I. Trees untreated with B served as a control.
The results showed that B fertilization had effect on B concentration in leaf tissues, mostly after ripening. B was present significantly higher amount in leaf in treated samples after ripening.
Mean fruit weight was slightly increased by B fertilization. Fruit sensitivity to cracking was not influenced by B fertilization. Nevertheless, from our data it can be conclude that the sensitivity of fruit to cracking is improved when the fruit is riper, the fruit density and fruit weight are higher. The soluble solids varied between 15.0 and 15.9% according to the treatments. Our results for the monosaccharides investigated varied between 5.1 and 7.2 as glucose and fructose as well. Galactose and sucrose was detected very small amount in the unprocessed cherries. Applied B treatments increased sugar contents but decreased organic acid contents in sweet cherry fruits.
It is concluded that under conditions of this experiment, B fertilization can be recommended in sweet cherry culture to improve fruit quality and their appearance.
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The after-effect of paclobutrazol on morphological characteristics of in vitro Narcissus poeticus ssp. radiiflorus plants
43-46.Views:176After different pre-culturing period (12, 23 or 34 days) on ½ MS medium with 1 mg l-1 paclobutrazol, 1 mg l-1 N6-benzyladenine and 0.1 mg l-1 1- naphthaleneacetic acid , 3 groups of Narcissus poeticus ssp. radiiflorus bulb scales were kept on the same medium without hormones. The results were evaluated monthly and the final one happened after 7 month. The best results were achieved due to the shortest pre-culturing period (12 days; Group 1), with 4.9 bulblets and 4.54% hyperhydricity. The result of the second treatment (pre-culturing period of 23 days; Group 2) was not different significantly but the number of bigger bulblet were higher (4.54 bulblets). After the longest pre-culturing period (34 days; Group 3), the number of bulblets was low (3.68) and more hyperhydricity (18.18%) was detected. The highest number of roots (13.91) was observed in this group
very likely due to the strong after-effect of paclobutrazol. -
Comparative organoleptic examination of apple varieties developed by different environmentally safe technologies
69-70.Views:143Ecological or biological growing techniques are generally recognised as actual trends in agricultural production. The objective of our experiments is a comparison of apple fruits grown alternatively by integrated versus ecological technology. In a collection of varieties, the possibility of the experiment was feasible. At the same time, a comparison of the popularity of existing varieties was also actual. The organoleptic consumer’s tests rated the varieties, and the comparison with instrumentally raised “objective” data could be compared with the subjective ratings, which did not coincide with each other. This phenomenon was revealed in the rating of acid-sugar harmony, where the internationally used quality index of Thiault produced a different range of the samples then the consumer’s test. The same contradiction was observed between ratings of firmness and the data raised by penetrometer.
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Effects of silicon in plants with particular reference to horticultural crops - Review article
95-105.Views:294Silicon (Si) has long been considered as non-essential element for plant’s growth and production. Numerous efforts are being made for the discovery of its beneficial effects with large scale studies laying foundation for new findings and hypotheses. Therefore, Si has been suggested to be a quasi-essential element due to its positive effects against biotic and abiotic stresses alike. Though Si is the second most abundant element in the soil profile, its availability to plants is limited to the form of monosilicic acid only. Besides, plants’ ability to take-up Si and use it in their physiological processes also depends on the available transporters associated with it. Thus, the present review covers uptake and transport of silicon in plants as well as Si mediated physiological processes, including mechanisms underlying induced tolerance against biotic and abiotic stresses with a particular emphasis on horticultural species.
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High antioxidant - and anthocyanin contents of sour cherry cultivars may benefit the human health: international and Hungarian achievements on phytochemicals
45-47.Views:314Evidence suggests that a diet with high fruit and vegetable consumption may decrease the risk of chronic diseases, such as cardiovascular diseases and cancer, and phytochemicals including phenolics, flavonoids and carotenoids from fruits and vegetables may play a key role in reducing chronic disease risk. Recent research has proved that sour cherry (Prunus cerasus L.) is a valuable natural source of some bioactive compounds important in human health preservation. According to the published data, the most important biological effects of sour cherry are connected — directly or indirectly — to their endogenous antioxidant behaviour as well as to their specific pattern of anthocyanin components. In the present work, we measured the total antioxidant capacity of some Hungarian sour cherry varieties in combination with their anthocyanin-, and vitamin-C content. In 2003, twelve clones were selected and grafted from a local sour cherry population called "Bosnyák" sour cherry grown in small home gardens and farms of the village Csengod (Great-Plain Region, South Hungary). Other Hungarian sour cherry varieties, i.e. cv. Újfehértói fürtos, cv. Érdi bőterrnő, cv. Debreceni bőterrnő, cv. Csengődi and cv. Kántorjánosi served as a control.
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Effect of boron nutrition on nutrient uptake and fruit quality of tart cherry in Eastern Hungary
45-48.Views:251Effect of the foliar boron (B) application on nutrient uptake and fruit quality of tart cherry (Prunus cerasus L.) was investigated from 2008 to 2009 on mature four favourite Hungarian tart cherry cultivars like ‘Oblacsinszka’, ‘Érdi bôtermő’, ‘Újfehértói fürtös’ and ‘Petri’. Tart cherry trees grown in Eastern Hungary (Újfehértó) on an acidic sandy soil with low B content. Trees were treated with B by foliar application (0.5% B) at full bloom and untreated with B served as a control. B sprays strongly affected on B content of inflorescences. However, B sprays had no consistent effect on summer leaf B status. In our experiment stronger year effect was observed at leaf B status than flower B status. The effectiveness of early spring boron applications are limited and mostly affected the flower B status only. Moreover, treatments had inconsistent effect on studied fruit inner parameters. Monosaccharides, vitamin C and organic acid contents of sour cherry were stronger affected by cultivars than applied treatments.
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Antioxidant capacity, total phenolics and mineral element contents in fruits of Hungarian sour cherry cultivars
59-64.Views:355Several epidemiological studies revealed that the consumption of antioxidant compounds and the risk of atherosclerosis, increased blood pressure or cancer are inversely proportional. Fruits of sour cherry contain a wide range of antioxidant compounds including melatonin, perillyl alcohol, ellagic acid, several flavonoids, polyphenolics, and anthocyanins. This study was carried out to survey the antioxidant power and mineral element content of seven commercial sour cherry cultivars and three cultivar candidates and to assess the influence of some external conditions on fruits' functional properties. Our analysis revealed nearly 5- and 2-fold differences between the lowest and highest antioxidant capacities and total phenolics content, respectively. Some cultivars (`Kántorjánosi' and ‘Újfehértói fürtös') and cultivar candidates (D, 'Petri' and 'Éva') showed outstanding antioxidant capacity and total phenolic content; in addition, mineral element content in fruits of the ‘Újfehértói fürtös' cultivar was also favourable. Redox parameters of fruits were influenced by the cultivation plot or fruit positions within the canopy in about half of the cultivars tested. Genetic background of cultivars forms the decisive factor in determining fruits' antioxidant capacity, although external factors may have also sizeable modifying effects. Enhanced functional properties of the fruit may also be further increased through breeding programs since considerable variation exists within the tested germplasm.
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Examination of nitrogenous compounds in Hungarian bio-musts
109-113.Views:314There has not been any research done on the musts from organic grapes. As a result of the special technologies in organic farming we can expect bio-musts to have a different quantitative and qualitative composition of nitrogen compounds from that of traditional musts. In our present essay we deal with the tests of nitrogenous compounds (assimilable nitrogen content, aminoacid, biogenic amine content) in musts from Hungary's bio-wine cellars. Our results show that the change in procedures has resulted in neither quantitative nor qualitative changes in the nitrogenous compounds of bio-musts.
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Comparative evaluation of chamomile (Matricaria recutita L.) populations from different origin
91-95.Views:354In our research project under cultivation we examined 4 cultivars ('Soroksári 40', 'Lutea , 'Goral', 'Bona') and 28 wild populations of chamomile assuring all of them the same environmental conditions. Plant height, flower-diameter, essential-oil content, and the main terpenoid and flavonoid composition were analysed. The aim of our study was to establish the genetic background of breeding a new cultivar as well as encircle those natural habitats that give chamomile drug with the best quality.
In the case of plant height populations from the Great Hungarian Plain were lower than plants from Transdanubia and the control cultivars. Between the wild and the standard individuals we found significant differences with relevance to the flower-diameter. With regard to the essential oil content the populations were very heterogeneous even those, which came from the same habitat. Populations form Transdanubia and Nagyiván reached the essential oil level of the cultivars (0.721-0.931 gi100g), and 75% of the examined plants exceeded the minimum requirement of the PhHg VIII.
According to the essential oil composition our previous statement was confirmed that in the populations of Transdanubia and Northern part of Danube—Tisza Mid Region the main component is bisabolol-oxide A (30-41.2%), while plants native to the territory cast of the river Tisza are mainly characterised by a-bisabolol (32.3-48.4). In some samples the ratio of bisabolol-oxide B was more than 10%. The chamazulene content was higher in the cultivars selected to this component (above 20%), than in the wild populations (varied between 1.22 and 17.2%). Populations originated from the central part of Hortobágy region had extremely high apigenin content (10-13 mg/g), but in the case of chlorogenic acid, hyperoside and quercitrin we did not find any differences affected by the origin.
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The effect of 5-aminolevulinic-acid (ALA) on the development of Saintpaulia ionantha
33-36.Views:233In recent work the effect of 5-aminolevulinic-acid (ALA) agent (commercial name Pentakeep-V) was examined on the chlorophyll content, growth and development of Saintpaulia ionantha. The newly re-rooted potted plants were irrigated or sprayed with 0.3‰ or 0.5‰ Pentakeep-V solution, and plus 30% long lasting fertilizer was added to half of the all treatments. Control plants were sprayed with tap water. Best result were obtained on the field of flowering. All the treatments promoted chlorophyll-content in the leaves especially spraying with 0.3‰concentration. Plants treated with Pentakeep-V in both concentrations and independently from the spraying or irrigation flowered more than two weeks earlier than control and those that got plus 30% fertilizer. Besides in the case of some treatments the diameter of leaf rosette, the number and surface size of leaves grew comparing to the control. The longlasting fertilizer had positive effect on the fresh weight but none of treatments had effect on the dry weight.
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Carbohydrate utilization of Erwinia amylovora in vitro
31-34.Views:152Nectar 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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Vegetative and micropropagation potential of Piper guineense (Schumach and Thonn)
29-36Views:106The continuous loss of forest plants due to deforestation, and the increasing demand for Piper guineense because of its medicinal and food value, has put a permanent pressure on its population in the wild where it is collected. A method for conservation and mass propagation is therefore required. This research was undertaken to determine the optimal concentration of auxin needed for vegetative propagation and to investigate the potential of Piper guineense for micropropagation. The auxin optimization study of vegetative propagation was based on the use of two-nodal stem cuttings treated with five different concentrations of indole-butyric acid (IBA). Growth parameters such as the number of sprouted, rooted and survived cuttings among others were determined. To investigate the potential of Piper guineense for micropropagation, nodal explants were subjected to different sterilizing treatments using ethanol, NaOCl, mancozeb, streptomycin and Plant Preservative Mixture (PPM). The effect of plant growth regulators (PGRs) was tested on sterilized nodal explants using full strength Murashige and Skoog (MS) hormone-free media alone as control and MS media supplemented with PGRs (BA, NAA and KIN) at different concentrations and combinations. Significant differences were observed across the treatments for all growth parameters measured. However, 2000 ppm IBA significantly (p<0.05) influenced sprouting and rooting of the stem cuttings. Piper guineense explants have deep tissue contaminants, which cannot be eradicated by surface sterilization alone except double sterilization using PPM. On control media, neither shoot nor root response was observed while the highest percentage of induced roots was obtained from explants cultured on MS +1 mg/L BA + 0.25 mg/L NAA. Shoot induction was only achieved when BA was used alone and when subcultured on media supplemented with NAA, which generated roots.
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Relaco: a product to reduce water shoot formation around pruning wounds in pome fruit trees
30-31.Views:105Larger cuts made during the winter pruning of pome fruit orchards a number of serious problems: the wounds serve as entrances for several branch-infecting pathogens, the numerous water shoots formed around the cut edges consume assimilates, shade the developing fruits, make the canopy dense, reduce the effectiveness of the pest management and cause extra work during next seasons pruning work. These problems can be eliminated by using proper wound protectants, like Relaco, a new Romanian wound protectant to cover larger pruning cuts of apple, pear and quince trees.
The treaments by Relaco resulted in a significant decrease in both the number and total length of water shoots formed around the cut egdes.