Genetical 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 genetica...l 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.
In 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 progr...amme 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.
The use of pathogen-free planting stock for new vineyard establishment is a key component in the maintenance and expansion of vine and quality table grape production. The success of the necessary changes in the structure of the grape industry is forced by the globalization process, the climate change, the rediscovery of autochton varieties as w...ell as breeding of new tolerant and resistant varieties. The renewal of vineyards largely depend on the availability of planting stocks. Serbia and Hungary found a common interest in establishing pathogen-free stock materials from newly breed resistant varieties and clonal selections of varieties which are traditional in the Serbian-Hungarian border area. During a cross-border cooperation program a complex system for the production of pathogen-free grapevine propagating material was established. Using heat therapy, in vitro shoot tip culture and traditional and molecular diagnostic techniques new pathogen-free stock materials were established from 26 varieties. They have been or will be tested for the presence of most important grapevine viruses, phytoplasmas, as well as bacterial and fungal pathogens. The complex system applying green grafting for indexing on grapevine indicators can shorten the duration of the procedure from 4 years to two-three years.
High 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, w...hich 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.
The plantation of intensive growing orchards and steady increase in yield is essential to return the growing cost by sale. Seasonal crop fluctuation of pear is increased by the frequently occurrence of drought and climatic changes. This study reviews genetic and growing factors determined the alternancy of pear and present the new knowledge con...cerning on water saving irrigation techniques. Use of dwarfing rootstocks, root pruning, branches pruning and new water saving irrigation make the changes in vegetative and generative growth that successfully improve the alternancy of pear growing. According to publications BA 29 of clonal quince rootstocks exhibited the best protection mechanism against to drought. Regulated deficit irrigation (RDI) applied during rapid shoot growth and slowly fruit growth result a decrease in shoot growth and 60% of water saving in pear orchard while there was no influence on harvested yield. Partial rootzone drying (PRD) microjet irrigation applied in pear orchard result 23-52% of decrease in water use, however concerning explorations are contradictory. Further investigations need to improve the efficiency of new irrigation technology adapted pear varieties based on monitoring of soil water status and measurement of stem water potential as stress indicators of plants.
Black locust (Robinia pseudoacacia L.) is a valuable stand-forming tree species introduced to Europe approximately 400 years ago from North America. Today it is widely planted throughout the world, first of all for wood production. In Hungary, where black locust has great importance in the forest management, it is mainly propagated by...seeds. But since the seed-raised plants present a great genetic variation, this type of propagation can not be used for Robinia’s improved cultivars. In the Hungarian black locust clonal forestry, propagation from root cuttings can be used for reproduction of superior individuals or cultivars in large quantities. However, this method demands more care than raising seedlings from seeds and can be applied with success in well-equipped nurseries.
Black 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.
The paper gives a review on the results of the latest rootstock evaluation projects in Hungary. Several cherry rootstock evaluation projects were carried out in Hungary during the last two decades. The evaluated rootstocks are partly mahalebs selected in Hungary, but more or less all the most important new rootstocks from different countries ar...e involved. The aim of these evaluation projects was to find appropriate rootstocks in a wide range of vigour for our climate and soil conditions. The conclusion of the last 20 years of research in Hungary proved just the opposite of believes, that high density orchard can only be planted with dwarfing rootstocks. Before choosing the right rootstock the most important is to consider adaptability, precocity and productivity. Dwarfing and semi-dwarfing rootstocks showed proper results only with irrigation or very good site conditions. These rootstocks are very precocious, but branches form easily blindwood. This must be corrected by severe pruning in the first years. The relatively small leaf surface area can also be disadvantageous, but it can be controlled by pruning, fruit-thinning, irrigation and fertilization. After studying different rootstocks semi-vigorous rootstocks seem to be the most adequate for different site conditions in Hungary. Fast initial growing and competent precocity are their favourable characters. From the vigorous group of clonal mahalebs or seedlings are highly recommended first of all for poor site condition (sandy, lime soils with high pH). They turn to bearing early and easy to find them in the Hungarian nurseries. But on vigorous rootstocks trees might need stronger summer pruning.
The 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.