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Plopa C.,Romanian Research Institute for Fruit Growing | Preda S.,University of Craiova
Acta Horticulturae | Year: 2013

Apple mosaic virus (ApMV) produces variable symptoms on infected apple both in the nursery and in orchard. Severe strains of the virus can induce severe necrosis and reduce the production of fruit buds by 20-40%. Obtaining ApMV-free plants in apple was tested by using meristem culture. The research was conducted on three virus infected: 'Golden Delicious', 'Golden Spur' and 'Lord Lambourne'. Identification of the virus was done by DAS-ELISA serological test and bioassay Cucumis sativus plant, which produced chlorotic lesions on cotyledons. Infected biological material was inoculated on QL culture media with the growth regulators 0.01 mg/L IBA and 0.3 mg/L GA3. Explants had two dimensions: 0.3 mm and 1.0 mm. Multiplication phase was achieved on MS culture medium supplemented with 1.5 mg/L BAP and 0.5 mg/L ANA. Rooting was conducted on MS medium with two growth regulators 2 mg/L IBA and 0,5 mg/L GA3. After rooting of the plants from root meristems of 0.3 mm, diagnosed viral testing was positive for 58% of 'Golden Delicious' variety, 52% for the variety 'Lord Lambourne' and 50% for the variety 'Golden Spur'. Plants derived from meristems of 1 mm in size were diagnosed infected at a rate of 83% in 'Golden Delicious' variety, 80% in 'Lord Lambourne' and 77% for the 'Golden Spur' variety. Source


Florea A.,Romanian Research Institute for Fruit Growing | Teodorescu A.,University of Pitesti
Scientific Papers of the Research Institute for Fruit Growing | Year: 2012

The worldwide trend of plantations fertilization imposed a new concept in this field. On one hand, it was abandoned the idea of using large amounts of fertilizer to force the obtaining of high yields, and on the other hand, increasingly require more and more application of organic and unpolluted fertilizers. In practice, the nutritional control of strawberry is very difficult, because a large number of factors influence the absorption and availability of nutrients through mechanisms that are not fully understood. Aim is to establish concrete measures for improving crop technology by applying optimum dose of fertilizers, leading to increased productivity and fruit quality of strawberry culture. The research was conducted during 2009-2010, in a two-way experience. It was located at the Research Institute for Fruit Growing Pitesti. Experimental factors were: A -cultivars: a1 -'Onebor', a2 -'Real', a3 -'Elsanta', a4 -'Mira', a5 -'Alba', a6 -'Premial'; B -Fertilizer with 6 graduations: b1 -unfertilized, and for graduations b2 -b6 were applied mixtures of the below fertilizers the amounts becoming increasingly larger, thus: b2 -6.4 kg / ha / week, b3 -14.3 kg / ha / week, b4 -21.4 kg / ha / week, b5 -28.5 kg / ha / week and b6 -35.8 kg / ha / week. The fertilizers applied were: Polyfeed (N19: P19: K19), K nitrate (N12: P0: K43: Mg2) and Magnesia (N11: P0: K0: Mg15). Mixtures were applied at 2 weeks intervals, as follows: 1 April to 15 May (flowering), 2 applications, containing macroelements N: P: K: Mg 14:6,3:20,7:5,7 g / 100 g mixed fertilizers, May 15-June 15 (in the picking period), 2 applications of N: P: K: Mg 10,2:6,3:13,5:2,83 g/100 g blend fertilizer and August 1 to September 15 (2 applications) with N: P: K: Mg 12,2:6,3:20,7:31,6 g/100 g mixed fertilizers. Following determinations were made: average weight of fruit (g) by weighing a sample of 250 fruits, fruit soluble dry matter (%), refractive, total acidity (g of Malic acid/100 g fresh matter) iodometric method. Experimental treatments have led to differences in the acidity of the fruit. Thus, the analysis of fertilizer doses on the chemical components of the fruits of the six studied cultivars, we concluded that V5 and V6 treatments had a positive influence on pH of the fruits of 'Premial' cv. (3.460), 'Elsanta' (3.400) and 'Mira' (3.460). Treatments induced also, highest average fruit weight in variety 'Mira' (45,025 g), weight varies as compared to the control (32.795 g) and from other experimental versions of the same variety. Average dose of fertilizer belonging V4 and V5 variants showed the highest values of fruit dry matter content of the variety 'Premial' (65.55%), respectively (7.570%), higher values the witness variant and other variants analyzed. Source


Sutan A.N.,University of Pitesti | Popescu A.,University of Pitesti | Isac V.,Romanian Research Institute for Fruit Growing
Romanian Biotechnological Letters | Year: 2010

As some of the ornamental varieties of strawberry obtained from Fragaria x Potentilla crosses are lacking the ability to form runners, their in vitro propagation is dependent on either direct or indirect organogenesis. The influence of culture medium composition and explant type were investigated in two genotypes of ornamental strawberry, "Pink Panda" and "Serenata", respectively, in order to establish an efficient protocol for regeneration by indirect organogenesis. Aiming to a good rate of callogenesis and shoot regeneration, the effect of different combinations and concentration of growth regulators (2,4-D, IBA, and BAP) added in culture media (either MS or LF) were evaluated with leaf and petiole explants. It was found that the highest frequency of explants forming callus have been induced in both varieties investigated on the LF basal medium containing 0.5 mg/l or 1.0 mg/l 2.4-D and, respectively, 3.0 mg/l BAP. A maximum of 100% leaf explants, and 92% petiole explants formed calli having characteristics of those regenerating shoots in "Serenata" variety. Similarly, a maximum of 92% petiole explants formed callus in "Pink Panda" intergeneric variety. © 2010 University of Bucharest. Source


Halmagyi A.,Romanian Institute of Biological Research | Valimareanu S.,Romanian Institute of Biological Research | Coste A.,Romanian Institute of Biological Research | Deliu C.,Romanian Institute of Biological Research | Isac V.,Romanian Research Institute for Fruit Growing
Romanian Biotechnological Letters | Year: 2010

The aim of the present study was to investigate the importance of the preculture conditions on the survival of apple (Malus domestica Borkh., cv. Romus4 and rootstock M106) shoot tips cryopreserved using a combined droplet vitrification procedure. Preculture was critical for the survival of apple shoot tips after cryopreservation. Among the different tested sugars and sugar alcohols (glucose, sucrose, mannitol and sorbitol) sucrose treatment for 24 h was the most efficient one. After thawing and transfer of shoot tips on recovery medium the highest regrowth rates (68% for cv. Romus4 and 62% for the rootstock M106) were achieved after using the PVS2 vitrification solution. Plants regenerated from cryopreserved shoot tips did not displayed any sign of morphological alteration or abnormalities in growth in comparison with control plants. © 2010 University of Bucharest. Source


Halmagyi A.,Romanian Institute of Biological Research | Deliu C.,Romanian Institute of Biological Research | Isac V.,Romanian Research Institute for Fruit Growing
Scientia Horticulturae | Year: 2010

Two droplet procedures, droplet-vitrification (PVS2) and droplet (DMSO) were applied for cryopreservation of in vitro cultured apple (Malus domestica Borkh., cvs. Florina, Idared, Colmar and Rebra) plants. The highest post-thaw regrowth rates (70% for cv. Florina, 66% for cv. Idared, 63% for cv. Colmar and 60% for cv. Rebra) were achieved after using the droplet-vitrification (PVS2) protocol. The excised shoot tips (2-3 mm in length) were precultured in 0.5 M sucrose enriched media for 24 h. Subsequently they were transferred in PVS2 vitrification solution for 30 or 40 min (depending on cultivar) at 24 °C and then immersed in liquid nitrogen. Rewarming was performed in liquid MS medium at 24 °C. Plants regenerated from cryopreserved shoot tips did not display any sign of morphological alteration or abnormalities in growth in comparison with control plants. © 2010 Elsevier B.V. All rights reserved. Source

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