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The importance of clonal selection of grapevine and the role of selected clones in production of healthy propagating stocks
15-24.Views:291Genetical alterations and phytosanitary status promote the variability and modify the appearance of vine. Old vine varieties in old vineyards are highly variable and well adapted to selection. Clonal selektion is based on a visual performance: valuable individuals (clones) are picked out according to visible symptoms or characters. The genetical stability of clones is proved by testing the vegetatively propagated progenies on the basis of morphological and molekular (SSR, AFLP, SMPL, RAPD) markes. Authors take great care of the visual phytosanitary selection as part of the clonal selection being the oreliminary step to develop pathogen-free propagation stocks. In Serbia (Vojvodina) the selection breeding has been carried on for several decades resulted in comparative clone trials with home and imported clones of Welsch Riesling, Chardonnay, Pinot gris, White Riesling. Among the clones of home selection SK.54 Welsch Riesling clone is the most valuable. Its clearing from pathogene is being carried on in an interregional IPA programme (HUSRB/0901/214/123) in Kecskemét. In Kecskemét, the centre of the Hungarian Danube vine region 5 vine clones have been registered (Cegléd szépe K.73, Irsai Olivér K.11, Kövidinka K.8, Hárslevelû K.9, Pannónia kincse K.56). Besides them 18 virus-tested clones have also been qualified.Works aiming at their complete exemption are going on in order to obtain clones free of propagation wood-borne diseases.
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Promising white poplar (Populus alba L.) clones in sandy ridges between the rivers Danube and Tisza in Hungary
113-116.Views:174White poplar is a native stand-forming tree species in Hungary, covering 3.1 per cent of the forested area. More than 70 per cent of the white poplar stands can be found on calcareous sandy sites in the Danube—Tisza region, so they play a significant role in the poplar management of this part of the country. The most important task ahead of Hungarian poplar growers is to improve the quality of poplar stands and plantations based on selecting new clones and cultivars. The growth and yield of four promising white poplar clones was evaluated on a marginal site in central Hungary. The clones `1-1 425-4' (Populus alba x Populus alba), and 11 758' (Populus alba Mosonmagyaróvár 124) seem to be suitable for wood production, while the 427-3' (Populus alba x Populus alba cv. Bolleana) and 422-9' (Populus alba x Populus grandidentata) clones (with decorative stem form) could be better used for tree lines and ornamental plantations.
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Improvement of the grapevine variety ‘Kadarka’ by the selection of new clones
57-63.Views:164Red wine culture in Hungary was developed due to the grapevine variety ‘Kadarka’, originated from the Balkans, from the 16th and 17th centuries. ‘Kadarka’ was the first grapevine variety cultivated on the largest area in Hungary until the 1950’s, but its production area has been reduced significantly in the past decades. In the period of Hungarian grapevine reconstruction (from the 1960’s), the selection of the grapevine varieties and clones was determined by the system of cultivation (large growing space, large load and mechanized technology) that was based on the aspects of quantity. It did not promote the majority of the autochton and regional grapevine varieties to remain competitive. ‘Kadarka’ is a grapevine variety having an extraordinary variability in forms; however, a considerable part of its old stocks has disappeared. Nowadays, only two of its high yield clones are cultivated. ‘Kadarka’ becomes more differentiated from other, red wine producing, grapevine varieties, more preferred and newly requested by the fine aroma, spice, unique harmony of its wine less rich in tannin. The new market and environmental challenges in the field of wine production necessitate the preservation and improvement of the biological basis. In 2001 the Institute of Viticulture and Enology Pécs analyzed an old stock having a variability in forms in order to preserve the development and variability of the biological basis of ‘Kadarka’. Clones of great biological value were selected from it, with which the quality and yield security of ‘Kadarka’ can be increased. In 2010 and in 2012, six clones were submitted for state approval.
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Clonal selection of black locust (Robinia pseudoacacia L.) in Hungary: a review
153-56.Views:183Black locust (Robinia pseudoacacia L.) is the most important fast growing stand-forming tree species in Hungary. Its importance is increasing in many other countries, too. As a result of a new selection programme 13 black locust clones have been improved for setting up clones trials and seed orchard. In 2003 five of them (R.p. `Bácska', `Homoki', 'Szálas', `Oszlopos' and `Vacsi') were registered as cultivarcandidates. Tissue culture method has proved as a suitable mean of propagating superior individuals. The micropropagated plants have been growing successfully in the clone trials.
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The importance of pathogen-free grapevine propagation material in regards to clonal selection and rootstock breeding in Germany
11-13.Views:203High performing propagation material is essential for a reliable and economical production of quality grapes. Apart from genetic aspects pathogen-freedom is of prime importance in propagation material. In particular virus diseases cause major yield and quality losses and reduced longevity. This is also reflected in the current EU legislation, which focuses on the most common and dangerous viruses: GFLV, ArMV, GLRaV-I and GLRaV-III.Apart from these, locally occurring pathogens, e.g. phytoplasms or agrobacterium, are important as well and should not be present in propagation material. There are several ways to develop pathogen-free clones. Starting with already pathogen-free material is certainly the easiest case, but might not be feasible in local varieties with small acreages and limited vine numbers. In these cases the elimination of pathogens is required, either by heat therapy, tissue culture or somatic embryo genesis.
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Improved clonal approaches to growing black locust (Robinia pseudoacacia L.) in Hungary: a case study
53-56.Views:238In Hungary black locust (Robinia pseudoacacia L.) is considered as an important exotic stand-forming tree species and due to climate change effects its importance is increasing in many other countries. It has some desirable characteristics from both the practical and research standpoints. As a result of a partly new black locust selection programme new black locust clones were improved and a technology was developed for mass clonal micropropagation of juvenile trees. Clone trials with micropropagated plants were established in the country for evaluating the juvenile growth and the stem form of promising black locust clones under marginal site conditions. Significant differences (P<5%) were found for stem form value which partly verified the genetic gain of the selected clones against the common black locust. It was also proved that tissue culture could offer partly new prospects for the rapid mass cloning of selected genotypes.
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Promising black locust (Robinia pseudoacacia L.) cultivars in Hungary
18-20.Views:332In Hungary, black locust (Robinia pseudoacacia L.) is one of the most important exotic stand-forming tree species, growing mostly under unfavourable ecological conditions. Considering the climate change effects its importance is increasing in many other countries. As a result of a selection programme, several black locust cultivars have been improved for setting up cultivar trials. In the paper four black locust cultivars were evaluated in Central Hungary under arid hydrological and brown forest soil conditions. Significant differences (P<5%) were found in height, DBH, mean tree volume and average stem form value (SFV). At the age of 35 the cultivar ‘R.p. Jászkiséri’ appeared to be the most promising one for yield production and ‘R.p. Zalai’ for SFV.