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• Susceptibility of some traditional pear cultivars of Hungarian and foreign origin to the pathogenic bacterium Erwinia amylovora

  41-45.

  K. Honty

  M. Hevesi

  M. Göndör

  G. Tóth M.

  V. Bács-Várkuti

  A. Ferenczy

  Views:

  314

  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.

• Evaluation of the vegetative and generative performance of new apple cultivars in the Nyírség region

  39-44.

  Á. Csihon

  Views:

  476

  In this paper we examine apple varieties, which are planted expansively in the development apple orchards of the Western- European countries, but about its production characteristics we don’t have or just few practical experiences in Hungary. These varieties can be described with regular and high yields, aesthetic and alluring appearance in their origin places, what ensure profitable producing for the growers. Under the Hungarian climate which tends to be often extreme (hard cold winters, late spring frosts, summer drought, heat stress) these varieties may behave differently, so before the substantial planting it is expedient to carry out variety evaluations to avoid the later failures. The place of our experiments is located in the Nyírség representing adequately the ecological conditions of the surrounding areas, so the gained results can be adapted easily in the biggest apple production site of Hungary. Regarding the vegetative and the generative parameters of the 14 examined varieties (’Gala Venus Fengal’, ’Gala Decarli-Fendeca’, ’Galaval’, ’Jugala’, ’Gala Schnitzer (S) Schniga’, ’Red Cap Valtod (S)’, ’Early Red One’, ’Jeromine’, ’Crimson Crisp (Co-op 39)’, ’Red Topaz’, ’Wilton’s Red Jonaprince’, ’Red Idared’, ’Fuji September Wonder’, club cultivar) we found significant differences. The ratio of the thickness of trunk and the main branches showed that the trees have an optimal canopy structure in accordance with the Zahn principles, so they are in harmonious growing balance. The ‘Gala’ sport trained to slender spindle produced the highest yields, while the ‘Fuji’ and the ‘Red Delicious’ sport trained to super spindle can be described with the lowest values. All the cultivars reached the eating quality (65-70 mm), from which the ’Red Idared’, the ’Red Jonaprince’ and the ’Red Cap’ produced outstanding fruit size (81-85 mm).

• Fire blight (Erwinia amylovora) resistance in apple varieties associated with molecular markers

  53-57.

  J. Sehic

  H. Nyboom

  L. Garkava-Gustavsson

  A. Patocchi

  M. Kellerhals

  B. Duffy

  Views:

  505

  The invasive bacterial disease fire blight, caused by Erwinia amylovora has the potential to destroy fruit tree orchards all over Europe. Effective plant protection methods are lacking in many countries, highlighting the increasing importance placed on identification of germplasm with heritable disease resistance. Recent l y. a promising QTL (quantitative trait locus) was identified on linkage group 7 in the apple cultivar 'Fiesta· which is derived from ·cox's Orange Pippin' . I n the present study, 144 Swedish and foreign apple cultivars were analysed with the SCAR markers AE I 0-375 and GE-8019. which flank-. this QTL. Twenty-nine of the analysed cultivars had both markers. 78 had either AE I 0-375 or GE-8019, and 37 cultivars did not carry an) of the two markers. Seventeen cultivars. 7 with both markers and I 0 not having either of the two markers, were then inocoluted with the bacterium in a 4uaran1i ne greenhouse test. Cultivars carrying both DNA markers were significantly less susceptible than cultivars lacking the markers, P<0.001. Cultivars that were most resistant had both markers and had 'Cox· in their pedigree. Unrelated cultivars with the markers may still lack the QTL.

• Metaxenic pollen effect of scab resistant apple cultivars on the fruit of apple

  47-52.

  M. Tóth

  M. Gaál

  P. Bodor

  Views:

  396

  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.

• The fertilization problems of cultivated red- and black currant varieties in Hungary

  38-40.

  A. Porpáczy

  Views:

  249

  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).

• Comparative analysis of sour cherry cultivars on their ecological and biological indicators

  7-28.

  D. Surányi

  Views:

  639

  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.

• Comparative anatomical study of leaf tissues of scab resistant and susceptible apple cultivars

  43-45.

  D. Varga

  L. Udvardy

  Views:

  359

  According to previous studies some anatomical features seem to be connected with resistance or susceptibility to scab caused by Venturia ineaqulis (Cke./Wint.) in case of a given cultivar. Study of leaf anatomy of three scab resistant (‘Prima’, ‘Florina’, MR–12) and two susceptible (‘Watson Jonathan’, ‘Golden Delicious Reinders’) apple cultivars have been made. Preserved preparations made of leaves has been studied by light microscope. Studied parameters were: thickness of leaf blade, thickness of palisade and spongy parenchyma, thickness of epidermal cells, thickness of the cuticle. By measuring leaf thickness and epidermal cell thickness visible differences appeared in certain cultivars, while most conspicuous difference has been shown in thickness of the cuticle.
  
  

• The impact of location, row direction, plant density and rootstock on the sunburn damage of apple cultivars

  19-30.

  J. Racskó

  J. Nagy

  Z. Szabó

  M. Major

  J. Nyéki

  Views:

  1237

  The effect of row direction (N-S, E-W), plant density (conventional and intensive) and rootstock (M9, MM106 and crab apple) on the sensitivity of 41 apple cultivars to sunburn injury was studied at 6 locations (Derecske, Kálmánáaza, Nagykutas, Nagylapos, Siófok, Tornyospálca).

  During the observations the cultivars had rootstock-specific properties in respect of sunburn-susceptibility. Accordingly, the injury was decreased in the order: M9, MM106 and seedling rootstocks. The differences in sensitivity depend on the canopy of trees, caused finally by the growing vigour of rootstocks. Accordingly, the highest value of sunburn injury was observed on M9 rootstock, because this rootstock has a dwarfing effect upon the scion cultivars. Thus, vegetative area of these trees grow very slowly and the foliage is not enough compact to protect the fruit from solar radiation. The size and density of the foliage increased in the order: M9, MM 106 and crab apple seedling as rootstock. Moreover, relationships were demonstrated between the diameter of upper part of the crown, the leaf area, the number of fruits per tree and the injury of sunburn.

  Authors categorized the cultivars in respect of values of sunburn incidence: 1. „Not sensitive", II. „Moderately sensitive" and HI. „Strongly sensitive" categories were constituted. Generally, Topaz and Gala cultivars showed low damage (or were free from symptoms), in contrast to this, Golden mutants suffered relatively much. The most sensitive cultivar was Jonica on all the three rootstocks. We searched for relationship between the fruit quality parameters and the frequency of sunburn. Significant correlation was found in the cases of fruit size and the extent of cover-colour. The latter is interpreted with the fact that the best coloured fruits are found on the periphery of crown as a consequence of more intense irradiation.

• Continuous and discontinuous nectar secretion in some pear cultivars

  77-79.

  Á. Farkas

  Zs. Orosz-Kovács

  Views:

  220

  Hourly nectar secretion was studied in five pear cultivars between 1997-1999. Some cultivars (e.g. ‘Csákvári téli') secreted nectar continuously during the whole day, offering both nectar and pollen for pollinating insects. Discontinuous secretion (e.g. cvs. ‘Viki', `Nyárig tartó 6/19') is less advantageous from the viewpoint of insect attraction. In some cases, however, discontinuity or continuity of nectar secretion varied even within a cultivar (e.g. 'Solymári cukor', ’Jó szürke’) in different years.

• Old Hungarian grapevine cultivars and their relations characterized with microsatellite markers

  27-31.

  P. Bodor

  Zs. Varga

  T. Deák

  A. Pedryc

  Gy. D. Bisztray

  Views:

  535

  Thirty-one old Hungarian grapevine (Vitis vinifera L.) cultivars were investigated on 7 microsatellite loci to characterize them, to separate the cultivars from synonym names, and to confirm parent-offspring connections. Conculta (group of cultivars or bud sports) members, such as `Goher' and Tajor' representatives, were studied to find a suitable locus for the separation. Synonyms, conculta members, subcultivars and clones of Turmine, which was the most important cultivar of Tokaj, were also analyzed to separate the members of the different taxonomic levels. Pedigree of 'Kiralyleanyka' was examined to find the missing ancestor, because the parent-offspring connection between the natural hybrid and `Koverszolo' is questionable.

• The effect of nectar production to the gathering behaviour of honeybees and to the foraging activity of wild bees at apple flowers

  45-57.

  P. Benedek

  K. Finta

  Views:

  424

  Intensity of bee visitation (honeybees and wild bees), foraging behaviour of honeybees and nectar parameters (nectar production, sugar concentration, sugar content in nectars) were inspected at 18 apple cultivars for three consecutive years. Honeybee visitation was calculated to be some 3.07 bee visits at a single apple flower a day but wild bee activity was very low, only some 0.11 wild bee visits per flower per day.

  The nectar production (nectar content) of apple flowers was fairly different according to the cultivars and the nectar production (nectar content) of flowers was negatively correlated with the sugar concentration in nectar. Interestingly, at the majority of the inspected 18 cultivars the nectar production has shown minor or no changes in the morning and at the afternoon. The nectar production (nectar content) of flowers clearly encouraged the total bee activity at the inspected cultivars (r = 0.54). Bees visited abundant nectars with greater sugar concentration most intensely than lees abundant nectars with smaller sugar concentration.

  Nectar parameters, however, affected the activity of honeybees with different types of gathering behaviour in different way. More intense activity by pollen gatherer and mixed behaviour honeybees was observed at cultivars producing abundant nectar (pollen gatherers: r = 0.65, mixed behaviour: r = 0.79). The activity of pollen gatherer honeybees and of mixed behaviour bees, on the other hand, was negatively correlated to the sugar concentration in nectar (pollen gatherers: r = -0.51, mixed behaviour: r = -0.73). This can be explained by the fact that their behaviour was much more affected by the amount of pollen than by any nectar parameters. Accordingly, "mixed behaviour honeybees" should probably rather be called as "pollen gatherers with nectar load" instead of "nectar gatherers with pollen load", as widely used in literature. The activity of ineffective side worker nectar gatherers was greatly encouraged by the sugar concentration in nectar (p = 0.63), similarly to the pure (top) nectar gatherer honeybees (r = 0.72). There was a negative relationship between the nectar production (nectar content) of flowers and the activity of these behaviour classes (nectar gatherers: r = -0.47, side workers: r = -0.36).

  Concluding the findings we can state that the activity of pollen gatherers and mixed behaviour honeybees is strongly encouraged by greater nectar production (greater nectar content) of apple flowers. Their activity, however, is mostly dependent firstly on the amount of pollen. This is the reason why the sugar concentration is in a negative relationship to the activity of pure pollen gatherers and mixed behaviour bee. On the other hand, pure nectar gatherers and side worker nectar gatherers are greatly encouraged by the sugar concentration of apple nectar the amount of nectar was not a definite influence on their activity.

  Side worker honeybees occurred at each cultivar inspected, however, their ratio varied widely among cultivars. So we can draw the conclusion that, in contradiction with earlier believes, side worker nectar gathering is a general phenomenon at apple flowers. The activity of side workers depends first of all on the relative position of stamens and petals; however, low sugar concentration of nectars can probably moderate their activity but probably do not affect pollen gatherers and mixed behaviour bees.

  Wild bee visitation was very low; the wild bee species observed (Osmia cornuta, Andrena flavipes, Anthophora acervorum, Bombus terrestris, Bombus lapidarius and Halictus simplex) comprised some 3.44 per cent of the total bee visitation at apple flowers only. Wild bee visitation was in a positive correlation with the nectar production (nectar amount) of flowers (r = 0,4) and with the sugar content of nectar (r = 0.46) but it was negatively correlated with the sugar concentration in nectar (r = -0,27).

  Our result calls the attention to the importance of nectar parameters in the effective honeybee pollination of apple plantations. Most effective pollinating activity of honeybees can be expected in plantations with cultivars of high nectar production because this feature seem so encourage the activity of those behaviour classes (pure pollen gatherers and mixed behaviour bees) that are the most effective pollinating agents among honeybees.

• Cherry leaf spot incidence on 12 sweet cherry cultivars in integrated production

  65-67.

  A. Vámos

  I. J. Holb

  Views:

  610

  The aim of this study was to evaluate the cherry leaf spot (CLS) incidence on 12 sweet cherry cultivars in integrated sweet cherry production in three consecutive years from 2010 till 2012. Assessed cultivars (cvs.) were ’Aida’, ’Axel’, ’Biggareau burlat’, ’Blaze Star’, ’Celeste’, ’Germersdorfi 3’, ’Izabella’, ’Katalin’, ’Krupnoplodnaja’, ’Linda’, ’Sunburst’, ’Vera’Results showed that year had an essential effect on the CLS disease incidence. Cultivars showed great differences within years. Cultivar ’Celeste’ showed the lowest disease incidence on leaves in all years lower than 10%. The largest disease incidence on leaves was on cv. ’Sunburst’ in 2010, on cv. ’Germersdorfi 3’in 2011 and on cv. ’Axel’ in 2012. Disease incidence on these cultivars ranged between 10 and 25%.

• Clonal selection of black locust (Robinia pseudoacacia L.) in Hungary: a review

  153-56.

  K. Rédei

  Z. Osváth-Bujtás

  Zs. Keserű

  Views:

  398

  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.

• Tree growth and inner characteristics of fruits in pear cultivars

  29-32.

  J. Iváncsics

  Z. Vadas

  G. Jekkel

  Views:

  257

   

  Summary The aim of study was to investigate growth (crown growth and trunk diameter) and fruit characteristics [dry matter content (%), pectin (%), total acid (%) contents] of 10 pear cultivars ('Móri császár', 'Nyári Kálmán', 'Mogyoródi óriás', 'Fehérvári körte', 'Szegfa körte', 'Piroska', 'Mézes körte'). The crown development of the cv. 'Fehérvári körte' can be regarded as outstanding among the examined cultivars. The growth of the cv. 'Mogyoródi óriás' was low, this cultivar showed the poorest growth vigour. The width of the crown in several cultivars developed at a similar rate as the height of the crown. Outstanding values were shown by cvs. 'Fehervári körte' and 'Móri császár'. The development of trunk diameter was the highest for cvs. 'Piroska' and 'Hóka', and large growth of trunk diameter can be seen on cv. 'Fehervári körte'. Cvs. 'Mogyoródi óriás' and 'Mezes körte'showed weak growth. Outstanding dry matter content of fruits was measured on cvs. 'Fehervári körte' and 'Mézes körte'. The total acid content of fruits of cvs. 'Mézes körte' and 'Fehérvári körte'' was significantly different from the total acid content of cv. 'Mogyoródi óriás'. Pectin content was low in fruits of cvs. 'Mogyoródi óriás' and 'Fehérvári körte', while cv. 'Mézes körte' contained significantly more pectin. Vitamin C content we found was rather high in cvs. 'Mézes körte' and 'Fehérvári körte'.

   

• Changes in Some Quality Criteria During Controlled Atmosphere (CA) Storage of Peaches

  58-61.

  A. Eris

  B. Akbudak

  Views:

  235

  Intensive research has been implemented on different aspects of the bee pollination of pear in Hungary in the past decade, extending to the following topics: the effect of the opening sequence of the flowers within the inflorescence of pear cultivars on the effectiveness of bee pollination; the nectar production of flowers of pear cultivars; intensity of honeybee visitation and their foraging behaviour at the flowers of pear cultivars; flower constancy of honeybees to pear plantations; competition by weeds in bloom for bee pollination in flowering pear orchards; and some aspects to the bee pollination strategies of pear plantations (the effect of the limitation of bee pollination period on the set and the yield, possible compensation of frost damage of flowers by bee pollination in pear orchards, the optimal size of single cultivar block in pear plantations). The results of these studies are reviewed in this paper and some important aspects that need further studies are outlined.

   

• Effect of modified atmosphere package on apricot fruit storability

  30-32.

  A. Ezzat

  Views:

  377

  The aim of this work was to study the effect of modified atmosphere package (MAP) on apricot storability. Apricots (Prunus armeniaca L.) cultivar Jumbo cot were harvested at commercial ripening stage. The fruits were treated with different storage treatments as following: i) control storage for 13 days at 1 °C, ii) stored fruit at 1 °C for 10 days then 3 days at shelf at 25 °C, iii) fruit stored in MAP at 1 °C for 13 days and iv) fruit stored in MAP at 1 °C for 10 days then 3 days at shelf at 25 °C. Data showed the positive effect of MAP in keeping the apricot fruit for long time with better quality than the control fruit. MAP showed positive effect by recording the lowest fruit weight loss, the highest firmness and lowest chilling injury and fruit decay.

• Some aspects of disease management of cherry leaf spot (Blumeriella jaapii) with special reference to pesticide use

  45-49.

  I. J. Holb

  P. Lakatos

  F. Abonyi

  Views:

  1144

  In this review, some aspects of disease management of cherry leaf spot (Blumeriella jaapii) are summarised with special reference to pesticide use. In the first part of the review, we show the non-chemical control approach (e. g. removal of fallen leaves, planting resistant cultivar) against leaf spot. In the second part of the review, the effect of pesticides including fertilizers (urea) and fungicides on cherry leaf spot are discussed. Special attention are given to the fungicides of copper, dodine, captafol, captan, benomil, chlorothalonil, sterol demethylation inhibitors (e.g. fenarimol, fenbuconazole, myclobutanil, tebuconazole), and strobilurins about their effectiveness against cherry leaf spot. In the final part of the review, possibilities of cherry leaf spot control are discussed in integrated and organic cherry orchards.

• Preliminary results of fruit quality of resistant sour cherry clones in 2014

  31-34.

  B. Vaszily

  Views:

  331

  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.

• The inheritance and durability of scab resistance in apple progenies

  39-46.

  M. Tóth

  A. Pedryc

  Views:

  395

  In 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.

• Molecular analysis of strawberry cultivars using RAPD, AP-PCR and STS markers

  24-28.

  A. Balogh

  E. Kiss

  A. Szőke

  F. Dénes

  L. Heszky

  Views:

  314

  Seventeen strawberry (Fragaria x ananassa Duch.) cultivars representing the national list of Hungary, were subjected to RAPD, AP—PCR and STS analysis. Of the 31 decamer and oligomer primers tested 26 primers produced polymorphic patterns. 45 polymorphic fragments were analysed, ranging between 200-2800 by in size. Based on the data, similarity coefficients (Jaccard index and Simple matching coefficient) were calculated, and dendrograms were constructed using the unweighted pair group method of arithmetic averages (UPGMA). The dendrograms only partly reflect the known pedigree data. Specific RAPD markers were identified for cultivars F5, Pocahontas and Rabunda.

• Effect of postharvest sodium benzoate treatment on some fruit parameters of two organic apple cultivars

  35-37.

  B. Molnár

  Sz. Szabó

  Á. Veres

  I. J. Holb

  Views:

  1023

  The aim of this study was to investigate the effect of postharvest sodium-benzoate treatment on some fruit parameters of two organic apple cultivars (’Topaz’ and ’Florina’). Assessments were made at three times during storage: 17 November 2019, 20 December 2019 and 23 January, 2020. During every assessment dates, each fruit was observed separately, and determined the proportion of i) healthy fruits (%), ii) post-harvest fruit rot diseases iii) fruits with mechanical injury (%), iv) fruit with russetting (%), v) damage of codling moth and vi) Ca-deficiency symptoms. In addition, fruit weight (g) was measured at each assessment date. Sodium benzoate reduced the fruit decay and the proportion of healthy fruit was higher in this treatment compared to water treated fruit. This effect could be seen in all assessment dates and on both cultivars. Effects on other parameters were various according to cultivar and assessment dates. Loss of fruit weight was similar in both treatments and cultivars compared to control treatment.

• Influence of environment in electro-chemical quality of tomato

  17-20.

  S. Kaciu

  V. Shala-Mayrhofer

  N. Mirecki

  S. Aliu

  K. Jezik

  Views:

  327

  The aim of the research was to investigate the impact of different cultivation environments of tomato cultivars, the electro-chemical and the qualitative traits of the tomato fruits. The quality of tomato fruit harvesting was evaluated at the Laboratory of Institute of Horticulture and Viticulture University of Natural Resources and Applied Life Sciences, Vienna. Two hybrids of tomatoes were tested Belle-F1 and AmaF1, in two locations and two different treatments (open field and plastic tunnels). Model of experimental fields was based on random method and included three replications. Following parameters were analyzed and tested: pH, Rh, P-Value, Nitrates and the content of vitamin C. The values of pH for treatment in the open field and indoor production system were not significant (4.47 to 5.05). For P-Value derived from the two treatments the maximal values were without significant differences, while minimal values were significant. Study has shown also that the highest values of nitrate content (16.34 mg, open field) compared to average value differences were + 0.384 mg or 43.83% higher. In indoor production the nitrate content was lower in compared with plants cultivated in open fields, so these differences were +3.81 mg or 26.4 0%, and highly significant for both levels. In relation to vitamin C content, the highest value was identified in the indoor systemof 298.6mg, with variations from the overall average of 16.43% or + 42.15 mg. The coefficient of variation values for both levels was of 29.96 respectively 27.31%.

• Organic apple growing using sanitation treatments against apple scab

  11-13.

  F. Abonyi

  I. J. Holb

  Views:

  559

  Effects or sanitation practices were evaluated on primary and autumn infection by Venturia inaequalis in an organic apple orchard at Eperjeske on the moderately scab-susceptible apple cultivar Jonathan in 2005 and 2006. Evaluated sanitation practices were: i) collection of fallen leaves in autumn; ii) destroying fallen leaves by disc cultivation in autumn; iii) spraying fallen leaves with 2% lime sulphur in autumn; iv) spraying fallen leaves with 2% lime sulphur in autumn and then collection of fallen leaves in autumn; and v) untreated control. In both years, most sanitation practices reduced significantly (P< 0.05) scab incidence in the primary infection periods compared to untreated control. The highest leaf scab incidence was observed in the untreated plots (26:2 and 24.3% in 2005 and 2006, respectively), while the lowest was in the treatments of spraying fallen leaves with 2% lime sulphur combined with collection of fallen leaves (11.7 and 12.3% in 2005 and 2006, respectively).

• RAPD analysis of grapevine hybrids and cultivars

  63-66.

  J. Halász

  J. Korbuly

  T. Deák

  Gy. D. Bisztray

  Views:

  403

  Utilization of the Randomly Amplified Polymorphic DNA (RAPD) technique as a molecular marker was tested to investigate the relationships between some representative grapevine cultivars and hybrids established at the Department of Genetics and Plant Breeding (CUB), to distinguish clones as well as to characterize various hybrids between species or cultivars and their parents. Vitis vinifera cultivars were easily and successfully distinguished by the RAPD technique and they were grouped according to the traditional taxonomic classification. RAPD patterns of the examined Pinot gris clones proved to be completely identical. Number of generations was reflected by the value of genetic distance of the examined hybrids. Genetic identity of parents and their offsprings was influenced by the selection applied in the process of plant breeding. Parental phenotypic and morphologic characteristics showed high degree of segregation in hybrids, but RAPD analysis revealed that their genetic similarity is considerable. The three Vitis anntrensis clones were properly discriminated from every cultivar and hybrid of Vitis vinifera, i.e. hybrids are much closer to the cultivated grapevine than to V. anzurensis due to the phenotypic selection carried out during the life-cycle of one or two generations.
  
  

• Nectar production of pear (Pyrus communis L.) cultivars

  67-75.

  P. Benedek

  G. Kocsisné Molnár

  J. Nyéki

  Views:

  1093

  Detailed studies were made on the nectar production of 44, 16 and 18 pear cultivars, respectively, in a cultivar collection of pear during three consecutive years with highly different weather in the blooming. Results clearly show that pear does not necessarily produce small amount of nectar as stated in the world literature. In fact, pear can produce extremely high amount of nectar sometimes much higher than other temperate zone fruit trees species but its nectar production is highly subjected to weather, first of all to air temperature. Low nectar production seems to be more frequent than high one and cold weather can prevent its nectar production at all. On the other hand, results corroborate to the earlier statements on the low sugar concentration of pear nectar. There is a highly significant negative correlation between the amount of nectar produced by pear flowers and its sugar concentration (r = -0.52, n = 291, p< 0.001 for 1996, r = -0.34, n = 197, p< 0.001 for 1998). Sugar concentration in individual flowers may be up, to 40% in exceptional cases but generally it is well below 20%. Very high figures for sugar concentration in pear nectar at the literature seem to be incomprehensible. In contrast of some earlier statement in the literature no real difference could be established in the nectar production of pear cultivars, based on much more measurements than in earlier studies. Very low sugar concentration in pear nectar can explain the fact that the overwhelming majority of honeybees are pollen gatherers at pear trees even in the case of exceptionally high nectar production.