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  • Evaluation of foreign apricot cultivars in Hungary
    51-55.
    Views:
    152

    The extension and renewal of cultivar assortment is one of the key elements in the improvement of apricot production. Competitiveness can only be achieved by planting cultivars which meet all market requirements and yield reliably under the environmental conditions of the given production site. Beside breeding programmes, the range of cultivars can also be extended by the domestication of foreign cultivars. Most apricot cultivars have low ecological tolerance, therefore, cultivars improved or developed in other countries should only be involved in production after due consideration. The suitability of such cultivars has to be examined for several years. Foreign apricot cultivars have been tested in our cultivar collection for over 10 years. Hereby, the most important aspects of market value and the adaptability to the environmental conditions of the production site are demonstrated. According to the results of our examinations the production of early ripening 'Orange Red' and `Goldrich' can be promising in Hungary. From cultivars ripening in the peak season only those are expected to be widely produced which differ from Hungarian cultivars or surplus them in some respects. From the cultivars examined 'Harogem' which ripens at the same time as `Gönci magyar kajszi' has remarkably aesthetic fruits with glossy surface, while the large fruits of `Hargrand' has firm pulp. Late ripening cultivars have significant importance in the northern border of production. According to our examinations the cultivars 'Callatis', `Comandor and `Sirena' are applicable in Hungary to extend the harvesting season.

  • General defense system in the plant kingdom
    79-84.
    Views:
    136

    The goal of plant breeders is to improve the resistance of crops against virus, bacterium and fungus pathogens was easiest to achieve by selection for phenotypes displaying the hypersensitive reaction. The resistant plant of that type keeps its health by preventing or delaying the systemization of the pathogen by destruction of cells and tissues of variable size or amputation of the contaminated organs. The faster the reaction of the host plant is the more efficient and economical is the defense, since the extent of tissue destruction decreases proportionally with the speed of reaction.

    During a breeding program for resistance carried out on several plant species, mainly vegetables over thirty years, also an alternative defense reaction has been experienced, which fundamentally differs from the hypersensitive reaction. In that reaction the cells and tissues of the host plant being exposed to the pathogen do not die, on the contrary they hinder systemization of the pathogen by tissue thickening. An additional significant difference is that on the contrary to hypersensitive reaction this reaction is less host- or pathogen-specific and works excellently even at high temperature (over 40 °C).

  • Comparative analysis of sour cherry cultivars on their ecological and biological indicators
    7-28.
    Views:
    344

    Sour cherries developed in the northern hemisphere, an alloploid hybrid of dwarf sour cherries (Prunus fruticosa) and bird cherries (P. avium), born in the confluence of the two species. However, the ecological and, above all, cold tolerance of the ancestor of cultivated sour cherries is higher than that of wild cherries (De Candolle, 1894; Rehder, 1954; Terpó, 1974; Iezzoni et al., 1991; Faust & Surányi, 1997). The cultivation limits are in the northern hemisphere 38-44. degree. The Carpathian Basin, the Balkans and Asia Minor are considered to be the main birthplaces for sour cherries. The genetic and morphological diversity of sour cherries is greater than that of the basic species (Iezzoni et al. 1991; Faust & Surányi, 1997). In the study, 472 sour cherry cultivars were compared based on 7 relative ecological indicators and 3 biological values. Compared to other Prunus species, we mostly found less variability in sour cherries - not counting their salt tolerance (SB). The partial similarity between open pollination (OP), frost tolerance (FR) and disease resistance (DR) - partly true in terms of varieties, but also reflected the effects of purposeful breeding and selection. The cultivars together - in comparison, showed balance, but in the highlighting, the differences of the 3 cultivar groups became significant. Indeed, the differences between the species of the former Hungarian cultural flora are clearly different (Surányi, 2004), which is also the case when comparing a large number of apricot (Surányi, 2014), plum (Surányi, 2015) and peach (Surányi, 2020) varieties.

  • Application of DNA markers for detection of scab resistant apple cultivars and selections
    59-63.
    Views:
    108

    A DNA marker-based study was undertaken to identify the occurrence of major scab resistance genes in some apple cultivars and selections of importance for apple breeding. Unfortunately none of the RAPD-based markers previously reported to detect the Va, Vb, Vr and Vx genes produced unambiguous results. By contrast, the CAPS marker MI8 produced the expected three bands in all cultivars and selections already known or suspected to have the Vf gene, as well as in the Russian cultivar 'Antonovka Polotora Funtovaja' suspected to have Va resistance which however may be allelic to Vf. Vf-carrying selections and newly named cultivars 'Frida' and 'Fredrik' are grown successfully in Sweden without fungicides, suggesting that the Vr resistance breaking scab races 6 and 7 have not yet become a problem. The SCAR marker B12 detected the Vm gene in 'Prairifire', 'Rouville', clones 'OR45T132' and 'OR48T70', and selection '16-36-193'. The SSR locus 0102b10 detected one band at 118 by in 'Reka'. This is presumed to be identical to the Vr gene marker previously reported.

  • An investigation of genotype-environment interaction and stability for pea (Pisum sativum L) seed yield
    53-55.
    Views:
    109

    Eighteen pea breeding lines and three check cultivars were tested in two years with and without irrigation. The linear regression can explain only a small part of GEI so the use of regression technique was not possible for interpreting the data. In this case the ecovalence, stability variance and superiority measure stability parameters cannot describe properly the genotype's response. With the AMMI method it is possible to group properly the genotypes according to their response.

  • General defense system in the plant kingdom II.
    69-71.
    Views:
    131

    In addition to successes achieved in certain varieties in resistance breeding based on a defense reaction of host plants involving hypersensitive tissue destruction, resistant varieties putting a very strong selection pressure on pathogens have selected more and more aggressive types of pathogens. The never-ending race between plant and pathogen resulting from this can only be controlled by a defense system characterised by a different strategy. In each of the plant species that we bred a defence system was found, which contrary to hypersensitive reaction strives to keep the tissues at all costs and is not pathogen specific. This is implied in the term general defense system.

     

  • Experiments on the Resistance or Pepper Cultivars to Macrophomina phaseolina
    74-75.
    Views:
    124

    The ashy stern blight of pepper (Capsicum annuum) is often caused by Macrophomina phaseolina. Serious wilt disease occurred between 1994 and 1996 of pepper plants in Hungary. In 1996-98 screening experiments were made on many pepper cultivars. Culture (Knopp) solution experiments, pot experiments, greenhouse and field trials were carried out. We determined the incidence of disease by visual examinations, testing on PDA culture, and light microscope. There were significant differences in susceptibility of cultivars and breeding materials.

     

  • Exploring and preserving old apple cultivars of the Carpathian basin
    9-13.
    Views:
    177

    In a few scattered orchards of the Carpathian basin one can still find our most common historical apple cultivars and certain traces of traditional cultivation. We consider it an important part of the Department's breeding work to explore old apple cultivars which can be used as parent partners and sources of resistance, to identify them pomologically as well as to examine the production and marketing value of old cultivars recommended for cultivation in ecological production and in gardens. This paper documents the results of expedition and collecting work carried out in three regions of the Carpathian basin (foot of the Carpathian Mountains, Transylvania, Aggtelek karst area), and also the saving of old Hungarian apple cultivars preserved until present in the English National Fruit Collection. A total of more than 100 old apple cultivars and variations, as well as 13 valuable genotypes were collected during our explorations in the above mentioned four areas. A further aim of our work is to contribute to the protection of still savable archaic fruit production relict= areas and to the preservation of cultivars in the certain regions, and also to promote the recognition of the aesthetic landscape value of old apple trees and endemic orchards of old cultivars. Our good co-operating partners in this work are Aggtelek National Park, Farmer Club of Visk and the consultation centre of Hungarian horticulturist training beyond the border in Nyárádszereda.

  • Identification of plant taxons by isoelectric focusing
    65-67.
    Views:
    170

    Differences were demonstrated in esterasei coenzyme pattern of some essential oil producing plants belonging to the Apiaceae family — fennel (Foeniculum vulgare Mill.), angelica (Angelica archangelica L.), lovage (Levisticum officinale Koch.), dill (Anethum graveolens L.), coriander (Coriandrum sativum L.), anise (Pimpinella anisum L.), caraway (Carum carvi L.) — as well as differences between two varieties of fennel seed by using isoelectric focusing. That method provides quality control in essential oil plants and is suitable to describe isoenzyme pattern characteristic for taxons.

    Based on our findings, isoelectric focusing seems to be suitable for identification and differentiation of different plant samples, providing an easy tool for further processing as well as for breeding.

    Our further aim is to apply that method to differentiate among samples belonging to the same species according to their value of inner content.

     

  • Preliminary evaluation of selected Prunus spinosa and P. insititia genotypes for their nutraceutical properties
    19-22.
    Views:
    258

    Fruits of nine Prunus spinosa and P. insititia selections were compared in their ferric reducing antioxidant power and total phenolic content. The antioxidant capacity and total phenolic content ranged between 6.36 and 29.26 mmol AA/L, and 5.04 and 29.71 mmol GA/L, respectively. These ranges cover an almost 5-times variation among the tested genotypes. The Pearson’s coefficient was very high (0.92) indicating a major contribution of polyphenolics to the antioxidant capacity of the tested Prunus fruits. Conserving resulted in an approximate 20 % loss of antioxidant power and slightly increased phenolic contents. Our results led us to the conclusion that fruit of Prunus spinosa and P. insititia might be considered as rich sources of antioxidants. In addition, procession with heat treatment caused only a slight decrease in the antioxidant capacity without loss in the total polyphenolic content.

  • Biochemical changes in pear (Pyrus communis L. depending on different phases of the dormancy
    47-50.
    Views:
    159

    Pear cultivars of variable frost tolerance were tested as for frost injuries suffered as a consequence of artificial freezing temperatures during the endodormancy as well as the ecodormancy. Damages were registered according to a visually defined scale, then peroxidase and polyphenol-oxidase activity was checked in buds, spurs and limbs. According to our results, 'Packham's Triumph' was the most frost tolerant cultivar. Regarding enzyme activity of both enzymes, the performance of cultivars displaying different susceptibility was also different in spurs as well as in buds. Results referring to the endodormancy were especially instructive. During the ecodormancy, data obtained at the same time indicated the differences existing between the developmental stages of dormancy in the respective cultivars.

  • Effect of different cultivation methods on strawberry’s antioxidant value
    7-10.
    Views:
    389

    The small fruit and strawberry production is economically important in Serbian agriculture. The fresh fruit is sold in domestic markets, but the frozen and processed is mainly sold in foreign markets. The growers find themselves in an ever-expanding selection of the varieties, but besides the nursery and breeder’s descriptions of new cultivars, there are only few exact results for the biological and economical ability of the varieties, which makes easier to choose the proper cultivar. The performance of the varieties in modern strawberry production is worth to investigate by adaptive cultivation methods and production technique. In the case of new strawberry varieties we know neither their needs in production nor their real capability, so they have to be compared with an older, standard control variety (‘Clery’). The breeder’s manuals give only references for the needs of the production technique, of the variety, so it is necessary to have facts, which are based on objective testing results. In this work, a new variety (‘Joly’) is being compared with the control variety. Comparative study of individual varieties are required covering the antioxidant content of the fruits (FRAP) and variability of these amounts in different years of breeding as well as the production techniques under similar circumstances.

  • Metaxenic pollen effect of scab resistant apple cultivars on the fruit of apple
    47-52.
    Views:
    158

    As a part of an apple breeding program, we have examined the pollen effect on the fruit appearance and inner quality of different apple cultivars in the Corvinus University of Budapest Department of Fruit Science. Five apple cultivars ('Golden Reinders', 'Regal Prince', 'Rewena', 'Renora', 'Idared') have been crossed by the pollen of some new and some traditional cultivars in our experiment. The measurements were carried out in the analytic and fruit examining laboratory of the Department of Fruit Science. The diameter, height and stem length were measured by digital caliper. We have also examined the squash ratio, soluble solid- and acidic content. Sugar content was calculated by a schedule released by the International Sugar Committee (ISC). From the sugar- and acidic content, we could also count the Pomona-value.

    We have observed interesting effects according to some attributes in some crossing combinations with the help of statistical analysis. Crossing 'Golden Delicious' with 'Freedom', 'Prima', and 'Baujade' have resulted in smaller fruit size than other combinations. No significant differences could be observed on `Golden Reinders' fruits according to metaxenic coloration in the year of the examination. On the other hand the color modifying effect of pollen donating cultivars have manifested on the red fruits of 'Regal Prince' (Gala Must). `Freedom' as a pollen donating cultivar has resulted outstanding value in our consistency measurements. Squash ratio was the highest in combinations pollinated by 'Prima' and `Reglindis'. We have noticed balanced values when measuring inner qualities, only `Reka' has caused lower acidic content. Significant differences have been found in combinations according to the number of frivolous seeds. No frivolous seeds were found in the combinations 'Golden Reinders' x 'Freedom' and 'Idared' x 'Prima'. Almost two frivolous seeds were found in the fruits of the combination 'Renora' x 'Sóvári' in average.

  • Antioxidant capacity and total polyphenolic content in quince (Cydonia oblonga Mill.) fruit
    33-35.
    Views:
    269

    Fruits of twelve quince (Cydonia oblonga Mill.) commercial cultivars and selections were compared in the ferric reducing antioxidant power (FRAP) and total phenolic content (TPC) of intact and peeled fruits. The antioxidant capacity and total phenolic content ranged between 5.99 and 63.10 mmol AA/100 g FW, and 3.92 and 12.83 g GA/100 g FW, respectively. These ranges cover an almost 8-times variation among the tested genotypes in case of antioxidant capacity and also declares two-times variation for total polyphenolic content. Cultivars ‘Aromate’ and ‘Bereczki’ possessed the lowest antioxidant capacity and ‘Román portugál’ and ‘Bereczki’ had the lowest polyphenolic contents. In contrast, cultivars ‘Champion’ and ‘Konstantinápolyi’ possessed the highest antioxidant capacity and ‘Mezôtúri’ and ‘De Husi’ had the highest polyphenolic contents. The Pearson’s coeffi cient was relatively moderate but signifi cant (r=0.51) indicating a weak interdependence between FRAP and TPC values of quince fruits. Our results led us to the conclusion that quince might be considered as a valuable source of antioxidants and polyphenolics.

  • Recent findings of the tree fruit self-incompatibility studies
    7-15.
    Views:
    205

    This review endeavours to collect all recent and substantial contributions to the quickly deepening fields of tree fruit self-incompatibility studies and hence updating previously published reviews. Studies carried out to discover the molecular basis of gametophytic self-incompatibility are summarized and a newly described model for the solanaceous plants is also outlined. We describe recent findings in all economically important fruit tree crops involving apple, European pear, sweet and sour cherries, almond, Japanese plum, sloe, Japanese apricot, European apricot and peach. Additional DNA sequences are now available for both the pistil and pollen component genes in several species and their molecular, evolutionary or economic implications are discussed in the light of the fruit setting behaviour.

  • Transformation of tobacco plants with virEl gene derived from Agrobacterium tumefaciens pTiA6 and its effect on crown gall tumor formation
    53-56.
    Views:
    145

    The VirEl protein plays a key role in the transport of VirE2 protein from the bacterium to the plant cell during crown gall tumor induction by Agrobacterium. The virEl gene of A. tutnefaciens pTiA6 was cloned into the plant transformation vector pTd33 yielding pTd93virEl that was introduced into A. tuniefaciens EHA101 and used for tobacco transformation. The presence of the foreign DNA in the putative transgenic plants was confirmed by PCR analysis. Nine of the 41 transformed plants formed only small tumors following infection with the wild-type A. vitis octopine strain AB3. This property was inherited into the T1 generation. The expression of virEl gene in TI plants was demonstrated by Northern blot analysis.

     

  • Ecological drought resistance and adaptability of apple varieties
    113-122.
    Views:
    390

    For adequate yields in apple plantations, during the long growing period of the fruit primordia, one of the decisive factors is water supply. Indicators of stress are valuable signs for the diagnosis of drought and necessity of watering, i.e. planning the irrigation of plantations. The aim of the present study was to find reliable signs of water stress on apple trees and at the same time conclude on the drought tolerance of different varieties. The plantation of apple varieties grafted on various stocks and cultivated according to different systems (irrigated, non irrigated, integrate and biological) has been examined continuously by leaf analysis. Along the period of growing fruits, measurements were made in the field, then the leaf samples were analysed in the laboratory for composition of pigments, carbohydrates and antioxidants, as well as the histology of the tissues checked. Without irrigation, the mean leaf mass and the relative chlorophyll content (SPAD) of the variety Idared on M4 stocks increases beyond the values of 50 SPAD, whereas on M26 stock and integrated system, it declines. In the collection of varieties, grown according to the „integrated” system, during the development of fruits, ‘Gála’ and ‘Remo’ varieties have been affiliated to the “less susceptible” group regarding drought tolerance because of the leaf morphology, structure and content of SPAD and antioxidants. However, ‘Idared’ and ‘Jonagold’ belong to the “susceptible” group. To the same group are ranged the ‘Akane, Red Rome vanWell, Pink Lady’ varieties. Those varieties reacted to a short period of drought by increased production (content) of carbohydrates. Regarding changes of carbohydrate content ‘Greensleeves’ and ‘Ozark Gold’ varieties belong to the moderately water dependent (requiring) group. In the field, SPAD-tests facilitated the measurement of nutrient-uptake and incorporation, which is proved by the tight correlation between the data of SPAD and the increment of leaf weight (r=0.76–r=0.88), however, this depends on the variety too. SPAD is an indicator of water supply and is related with the density of stomata, cannot used for the selection of water-exigent varieties but for (drought) tolerant ones. In integrated culture, the (drought) susceptible varieties display (water-soluble) hydrophilic and lipophilic antioxidants (ACWand ACL resp.) the quantity of which may have some role in drought tolerance.

  • Comparative evaluation of chamomile (Matricaria recutita L.) populations from different origin
    91-95.
    Views:
    392

    In 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.

  • Virus susceptibility and resistance of Hungarian pepper varieties
    68-73.
    Views:
    160

    The aim of our study was to examine susceptibility or resistance of 18 pepper varieties to four viruses [tobacco mosaic

    tobamovirus (TMV), sowbane mosaic sobemovirus (SoMV), NTN strain of potato Y potyvirus  (PVYNTN) and cucumber mosaic cucumovirus (CMV). Out of the 18 varieties, 13 were resistant to CMV infection. Thirteen varieties were susceptible to TMV, while five ones (Dabora Fl, Brill Fl, Feherozon Synthetic, Ciklon Fl, Cecil Fl) showed only local hypersensitive reaction. All of the tested pepper varieties showed resistance to SoMV. Eight varieties (Tuba, Fehérözön Synthetic, Boni, Alba Regia, Korona, Édesalma, Cecil Fl, Star) were found to be resistant to PVYNTN. Out of the examined varieties five (Boni, Alba Regia, Korona, Édesalma, Star) were resistant to three viruses (SoMV, CMV and PVYNTN). Only one (Cecil F1) displayed complex, extreme resistance to SoMV, PVYNTN, CMV and hypersensitive reaction to TMV, therefore this hybrid is very important in pepper breeding and growing for virus resistance.

  • Preliminary results of fruit quality of resistant sour cherry clones in 2014
    31-34.
    Views:
    159

    The richness of Hungarian sour cherry cultivars in the world is unique; they can be consumed in many ways. Sour cherry is a Hungaricum and has excellent fruit quality and nutritional value. Nowadays the demand for chemical-free fruits is increasing. Reducing the number of chemical applications can be achieved most effectively by the use of resistant varieties, technological developments and cultivar innovation. The domestic and international sour cherry breeding programs use almost exclusively the resistant ‘Csengôdi’ clones as a basis. They are mainly Monilinia and Blumeriella resistant and have higher dry matter and antioxidant content. These pathogens influence not only the qualitative and quantitative parameters of the fruits, but may play an indirect role in the deterioration of the overall condition of the trees as well. The cultivation of resistant varieties can greatly reduce the pesticide load of the environment, so we can produce fruit with excellent nutritional value with fewer chemicals. Our aim is the expansion of the sour cherry assortment by introducing new  resistant cultivars. With this we can contribute to the spreading of environmentally sound production technologies and supply “super fruits” to the consumers.

  • Micropropagation of Rudbeckia hirta L. from seedling explants
    105-108
    Views:
    176

    We conducted experiments for developing an in vitro micropropagation protocol starting from meristems of Rudbeckia hirta L seedlings. We pre-soaked the seeds in sterile ion-exchanged water for 17 hours, and then achieved surface disinfection in two separate steps. First, we used concentrated household sodium-hypochloride solution for 20 minutes and, also for 20 minutes, we applied hydrogen peroxide of 10%, which was followed by washing with sterile ion-exchanged water three times. For the propagation of seedling meristems, the combination of half-strenght solid Murashige and Skoog (1962) culture medium containing 10 mg/1 of kinetin or 2 mg/I of kinetin + 0.1 mg/1 of 2iP proved to be the most suitable. The average number of shoot-buds developed from the seedling axillary meristem in the best culture media varied between 5 and 17. Without separating them, we inoculated the shoot-bud clusters on MS culture medium containing 2 mg/1 of IAA. After four weeks of incubation we obtained elongated shoots which we separated and inoculated into a new culture medium and we obtained elongated roots. The rooted plants were gradually acclimatised in the cultivation room, potted and carried to a greenhouse, and then planted in open field for subsequent observation. By adopting this method, our laboratory started the micropropagation of the superior and/or elite genotypes of the Rudbeckia hirta L. being of special value in respect of breeding.

  • The fertilization problems of cultivated red- and black currant varieties in Hungary
    38-40.
    Views:
    125

    Small fruits have a modest share in the fruit production of Hungarys. Red currant was grown traditionally in home gardens 60-70 years ago. Commercial production was established only in the surroundings of some town. The black currant was unknown until after Wold War II. An important change occured in small fruit production in the 1950s. Socialist countries, which had cheaper labour power, made efforts to meet these demands. In this time we produced 25.000 t.

    Presently the country produces 13-15.000 tons currant fruit yearly 60% from this is black currant, which has a better market. It is our own interest to make our currant production more profitable. The currant is the second most widely cultivated soft fruit. Our product is disposed mostly on EU markets.

    There was no breeding activity in this field in Hungary earlier. Cultivars used were mostly of foreign origin (W. European; Boskoop Giant, Silvergieter, Wellington XXX, Russian; Altaiskaya Desertnaya, Neosupaiuschaiasya, N. European; Brikltorp, Ojebyn). Besides well-known advantageous this cultivars have also some defects mainly unfavourable—adaptation to climatic conditions, which caused fertilisation problems, reduced the fruit set and uneven growth with decreased yields (Dénes & Porpáczy, 1999). About 140 black currant cultivars were investigated during the last four decades in our variety trials and only four of them were introduced with satisfying yielding capacity (3.5-5.5 t/ha).

  • A complex system for the production of pathogen-free grapevine propagating material
    59-62.
    Views:
    225

    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 well 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.

  • Effects of different pollination treatments in genotypes of Prunus salicina Lindl.
    141-146.
    Views:
    123

    The low productivity in the Japanese plum (Prunus salicina Lindl) is related with self-incompatibility characteristics, so other species or varieties that act as pollinators need to be present to improve fruit production. The objective of this work was to study the efficiency of pollination in different genotypes of P. salicina using treatments of natural self-pollination, cross-pollination with P. armeniaca cv. Giada and open pollination. These treatments were evaluated through viability techniques and in vitro and in vivo germination of pollen grains; the growth of pollen tubes along the pistil was also observed. Genotypes used in this study showed differences for each one of the pollination treatments. Some genotypes showed signs of self-sterility and interincompatibility with P. armeniaca cv. Giada, while others showed partial self-fertility characteristics or pseudocompatibility. Moreover, some genotypes showed a higher affinity coefficient with cv. Giada and these will be indicating a possible intercompatibility. These studies will be an important contribution breeding and selection of intra and intercompatible genotypes to be used in commercial orchards.

  • Susceptibility of some traditional pear cultivars of Hungarian and foreign origin to the pathogenic bacterium Erwinia amylovora
    41-45.
    Views:
    147

    Fire blight, a disease caused by the bacterium Erwinia amylovora (Burrill) Winslow et al., has been causing serious damage in Hungarian pear plantations since 1996. A prospective control measure could be the use of resistant cultivars. For that purpose ten pear cultivars have been tested under laboratory and greenhouse conditions for resistance to Erwinia amylovora strains collected in Hungary. Six of these cultivars are Hungarian ones of unknown origin, while four are traditional old varieties. Resistant cultivars should serve as germplasm for future breeding. Inoculations were made with a mixture of different pear isolates of the bacteria collected from various growing regions of Hungary (Ea 21, 23), at a density of 5x108 cells/ml. Susceptibility/resistance has been assessed on the basis of intensity of blight symptoms observed on shoots, flower parts and fruits. Cultivars were assigned to three susceptibility groups (low, moderate and high). Complete resistance was not found among the cultivars tested. The highest level of resistance was found in cultivar 'Kieffer', while the other cultivars displayed either moderate or high susceptibility to infection.