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Down-regulation of ethylene production in carnation (Dianthus Caryphyllus L.) by an apple derived ACC-cDNA
101-104.Views:135Transgenic carnations were produced with an apple derived antisense ACC-synthase cDNA. Transgenic carnation regenerants were potted in glasshouse. All transformed plants showed normal growth and were true-to-type. Ethylene production — measured at full opening stage — lowered by 30-60 %, no plant with 100 % decrease was identified. The vase-life has been observed for 5 years. 38 % of the transformant carnations showed a higher a relative value in days by more than 2 days to 6 days. Twenty six plants were found exhibiting the most marked alterations in the tested trait. In these plants ethylene production decreased by 37-67 %, they have longer vase-life (by 4 days or more). Since the fragrance variety 'Bíbor' was the plant material for genetic modification of vase-life, this trait has been conserved after transformation in spite of the fact that the position of transgene integration cannot be directed.
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Application of the Jerusalem artichoke (Helianthus tuberosus L.), as a plant origin medium additive, during the micropropogation of Ada keiliana
61-64.Views:193A procedure for in vitro propagation of Ada keiliana seedlings are suited for acclimatization, was worked out. M medium was supplemented, with Jerusalem artichoke, as plant origin complex additive. The apply of JAD (1,5g/flask) gave the best response, considering the shoot (29 mm), and the root development (24,9) mm) too. The plantlets with satisfying growth (25-30 mm, 4-5 roots) were transferred in small pine bark: Novobalt peat: coconut fibres: perlit (2:3:1:1) mix, among greenhouse circumstances.
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Production of transgenic carnation with a heterologous 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase bifunctional enzyme cDNA
75-79.Views:125Transgenic carnations were produced with a modified mammalian bifunctional enzyme cDNA coding 6-phosphofructo-2- kinaseffructose 2,6-bisphosphatase. Relative activity of this enzyme determines the fructose 2,6-bisphosphate (fru 2,6-P2) cytosolic concentration. This metabolite — as a signal molecule — is one of the carbohydrate metabolism regulators. The regenerated Dianthus chinensis and Dianthus caryophyllus shoots were selected on MS basal medium containing 150 mg/1 kanamycin. Transgene integration was proven by PCR analysis with cDNA specific primers followed by Southern hybridization of DNA isolated from selected green shoots, which survived on kanamycin containing medium, so 3 D. chinensis and 20 D. caryophyllus transgenic plants were produced. Transgene expression were examined by RT-PCR. Transformed and control plants were potted in glasshouse to evaluate the effect of modified fru 2,6-P2 on development, growth and carbohydrate metabolism.
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The inheritance and durability of scab resistance in apple progenies
39-46.Views:147In order to select the appropriate parent cultivars and maintain the durability of resistance, it is important to clarify the mechanisms of inheritance of scab resistance depending on the parents. It has been known that the progeny segregation ratios based on scab-resistance do not depend only on the genotype of the resistance locus but also on the genetical makeup of the donor and recipient parents as well as on the susceptible parent.
The aim of this study has been to demonstrate what factors in the Vf, Vr and VA scab-resistant cultivars — combined with susceptible and resistant parents — affect the inheritance and durability of resistance in seedlings in their first 4 year's growing four years' growth. After inoculating apple seedlings sown in 2001 with the suspension of Venturia inaequalis (Cke.) Wint. in the greenhouse, we studied the segregation ratios of the progenies into reaction classes. Seedlings showing resistance in the greenhouse were also evaluated for scab-resistance after they had been moved to the field and had naturally been infected with the pathogen in 2002 and 2004.
The majority of our results obtained in the greenhouse test, similarly to earlier experiences, have not justified monogenic inheritance at the phenotypic level. The effect of susceptible parent cultivars on the segregation ratio of progenies have become apparent again. The high infection rate of seedlings in the field trials, which had previously exhibited varying degrees of resistance in the greenhouse test, has raised concern. Our data has raised further doubts, concerning the durability of Vf resistance in Hungary. It is assumed that the composition of natural field populations of Venturia inaequalis in Szigetcsép has changed. The complexity of Vf resistance has been confirmed. The high infection rate in the progenies derived from Vf resistant cultivars draws the attention to the importance of utilizing additional sources of resistance.
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Investigation of the in vitro regeneration of mericlones in the caribe variety of carnation
87-89.Views:136In 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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Vegetative parameters of sweet cherry (Cerasus avium L.) cultivars in two training systems
42-45.Views:322Hungarian sweet cherry production has been changed recently. Thanks to the favourable selling prices many new plantations were established in the last years. In the new orchards mainly spindle canopy are trained, although many type of crown forms are used all over the world. In our study slender spindle and bush canopy were evaluated with three cultivars (‘Petrus’, ‘Vera’, ‘Carmen’) grafted on Prunus mahaleb rootstock. Vigor of the 3-4 years old trees showed spectacular differences. The highest vigor with Spanish bush was found for cv. ‘Vera’, but on slender spindle canopy the thickness values were medium. Meanwhile cv. ‘Petrus’ showed the highest trunk thickness with spindle canopy, but the lowest with Spanish bush. On spindle canopy cv. ‘Carmen’ presented the highest ramification ability, but its 2-3 years old twigs started to bald very early, which can be considered an unfavorable phenomenon. Bush canopy still can be described with strong vegetative growth on 3-4 years old trees, as vigor of spindle trees are more moderate.
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Pruning of plum trees and maintenance of balanced yielding
131-138.Views:241In this review, we give an overview of the pruning techniques that should be applied in commercial plum orchards. First, a detailed description of pruning for shaping the different crown types for the first, second, third, fourth and fifth years and the phytotechnical works is given for crowns with a circular projection area. Then, pruning for open crowns forms, such as the vase form is discussed. Following the shaping of the crown, it should be maintained by pruning. Detailed information is given on pruning for maintenance with special emphasis on the comparison of winter and summer pruning. In the following part of the manuscript, pruning experience is described separately for the major commercial plum cultivars in Hungary such as Cacanska lepotica, President, Bluefre, Stanley. Recommendations for cultivation systems under non-irrigated conditions are also included. Finally, light requirements, growth characteristics and suggested crown forms of the different cultivars are described for cvs. Ageni, Althan Tingle), Besztercei szilva Nm. 122, Bluefre, Cacanska lepotica, Cacanska rodna, Debreceni muskotály, Montfort, President, Ruth Gerstetter, Sermina, Stanley, Tuleu gras and Zöld ringló).
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Factors affecting rhizogenesis in vitro and acclimatisation of three cherry rootstocks
40-46.Views:135Factors affecting rhizogenesis in vitro and acclimatisation of three rootstocks of cherry, i.e. Mahaleb, Maxma-14 and Weiroot -10 were investigated.
Rooting was easily achieved within 2-4 weeks on MS-based liquid or agar-gelled media containing auxins IBA at conc. 0.49 or 2.45 pM or NAA at conc. of 0.49 pM. On liquid media with 2.45 pM IBA, a maximum rooting efficiency of 95-100% was obtained. However, high concentrations of auxin delayed the time of root initiation for 3-5 days.
Rooted plantlets were transplanted into pots with a mixture of 3:1 (v/v) peat:perlite and acclimatised gradually to field conditions with efficiency of 60%.
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Review on rain induced fruit cracking of sweet cherries (Prunus avium L.), its causes and the possibilities of prevention
27-35.Views:823The rain induced fruit cracking is a big, serious and costly problem for cherry growers. Cracked fruits lose their value and they are not marketable because of the poor fruit quality. Cracked fruits have different storage diseases and shorter storage and shelf life.
There are many influencing factors of the cherry fruit cracking such as: water uptake; fruit characteristics (fruit size, fruit firmness; anatomy and strength of the fruit skin, stomata in fruit skin, cuticular properties, osmotic concentration, water capacity of the fruit pulp, growth stage of the fruit,); orchard temperature and other environmental conditions;
The most effective protection technique is the plastic rain cover over the tree rows. The installation of these equipments is too expensive for the cherry growers. That is the reason why researchers tried to find other less expensive and sufficiently effective ways against the Lim induced fruit cracking.
Several calcium formulas: calcium chloride (CaC1,), calcium hydroxide (Ca (OH)2) and calcium nitrate (Ca(NO3)2 ) can be sprayed in appropriate concentration. Spraying with other mineral salts (aluminium and copper salts, borax) and PBRs (Plant Bioregulators) may be also effective to reduce fruit cracking.
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Nutrient demand of stone fruits
19-23.Views:150Effects of nitrogen, phosphorus and potassium fertilization were investigated on the change of nutrient content, vegetative and generative production of apricot, peach and sour cherry trees, as well as on frost hardiness in long term experiments. Nitrogen and phosphorus fertilization increased only the concentration of these elements in cherry leaves without effect on growth and yield. Consequent potassium effect was proved on these stone fruit species. Effect on yield appeared following the first higher crop load.
Potassium supply has positive effect on frost hardiness of apricot and sour cherry flowers and peach flower buds.
In peach, the lime content of soil decreased the yield but it could be compensated by potassium dressing to some extent. Favourable nutrient boundary values were determined for soil and foliage.