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• The KLP+ ("hat") trap, a non-sticky, attractant baited trap of novel design for catching the western corn rootworm (Diabrotiea v. virgifera) and cabbage flea beetles (Phyllotreta spp.) (Coleoptera: Chrysomelidae)

  57-62.

  M. Tóth

  É. Csonka

  I. Szarukán

  G. Vörös

  L. Furlan

  Z. Imrei

  J. Vuts

  Views:

  271

  In the course of research aimed at the development of non-sticky, easy-to-use alternative trap designs for the capture of selected beetle pests, a newly designed "hat" trap, codenamed CSALOMON® KLP+, was compared with conventional trap designs. In the case of the western corn rootworm (WCR) Diabrotica v. virgifera (Coleoptera, Chrysomelidae) the new KLP+ traps baited with pheromonal or floral baits were equally sensitive as the former PAL or PALs sticky "cloak" designs, but the KLP+ traps catch capacity and selectivity was much higher. When baited with the floral WCR bait, the KLP+ trap proved to be more sensitive in capturing female \VCR, than the former sticky PALs trap design.

  In capturing cabbage flea beetles (Phyllotreta spp., Coleoptera, Chrysomelidae), the new KLP+ trap design baited with allyl isothiocyanate performed better than the previously used VARL+ funnel traps in all respects studied.

  In conclusion, the new KLP+ trap design, baited with the respective attractants, appears to be advantageous to use for the trapping of both WCR and cabbage flea beetles, and can be recommended for use as a trapping tool in plant protection practice in the detection and monitoring of these pest Coleoptera.

• The effect of rootstock on the nectar production of apple cultivar `Idared'

  15-25.

  E. Nagy Tóth

  Zs. Orosz-Kovács

  Views:

  138

  Approaches based on the daily rhythm of apple flowers provide a new stage in nectar research, where the synchronous functioning of sexual organs is studied. In the flower biological studies the insect attraction of flowers was also studied. The two most important factors of insect attraction are the pollen- and nectar production of the flowers. From 1993 to 1998 we studied the food, that flower had to offer for the pollinating insects at different times of the day.

  Studies were carried out on 'Idared', one of the hybrids of 'Jonathan' apple cultivar. The fruit of 'Idared' is bigger than the fruit of `Jonathan'. It is bright red, transportable, has a bigger productivity and is not subject to Jonathan-spots. Concerning its inner characteristics, it is juicy, the flesh consistency is better than that of 'Jonathan', but its acid/sugar ratio is worse (Sansavini et al. 1981).

   

• The development and reproduction of grape phylloxera (Daktulosphaira vitifoliae Fitch) strains of Hungarian vine-districts in root-bioassays

  67-71.

  H. L. Tóth

  L. Horváthné Baracsi

  L. Kocsis

  Views:

  142

  The root bioassay method allows for 4-6 week continuous observation of grape phylloxera feeding on the grape root. 10 Hungarian phylloxera strains were compared on susceptible Vitis vinifera cv. Chardonnay and the resistant rootstocks of V. berlandieri x V. riparia Teleki 5C and V. berlandieri x V. rupestris Georgikon 121 in in vitro observations. The strains originated from Villany and Eger (Figure 3) had higher reproduction on the root of V. berlandieri x V. riparia Teleki 5C (201 and 119 eggs) and were more aggressive than the others (average production 10 eggs). The continuous high level of survival, development and reproduction of the Eger strain on Teleki 5C (V. berlandieri x V. ripuria) until day 46 may be due to adaptation.

• Variety specific integrated fruit production development in order to optimize inner content values

  27-31.

  E. Kállay

  G. Ficzek

  D. Andor

  M. Stéger-Máté

  G. Boronkay

  Z. Kirilla

  G. Bujdosó

  Gy. Végvári

  M. Tóth

  Views:

  193

  In this paper we introduce our results of three years (2007-2009) investigatio ns carried out in the framework of "Research and development in foodstaff chain" - project of Regional University Knowledge Center by the members of Corvi nus U niversity of Budapest - Department of Pomology and. Research Institute for Fru it growing and Ornamentals.  Budapest-Erd. The main objectives of the project were the followings: submi ssion of sour cherry candidate suitable for industrial process for state approval; determination of physica l parameter and inner content value changes of sour cherry varieties duri ng ripening; evaluation of health care attributes of sour cherry fruit; ripen ing process description by the colour and the force required to pick fruits of sour cherry. We stated that the optimal begi nning and period of the harvest can be determined wi th the fruit removal force. In this period the fruit growth stops. ju iciness rat io does not change. refractions are approximately equal.acidic content turns to decreasing trend.However the proportion of anthocyan in and polypheno l can still increase. Fruits harvested in this period fulfil a wide range of industrial process opportunities. 'Erdi jubileum ·and candidate IV-3/48 according to their inner content values arc suitable for high quality products (containing real fruit material in high proportion).

• The salt tolerance of vegetable paprika varieties

  39-45.

  K. Slezák

  I. Terbe

  N. Kappel

  K. Tóth

  Views:

  176

  In our experiments, we have chiefly tested the salt sensitivity of sweet pepper varieties. In cold forcing, 0.3 1/plant nutrient solutions of different NaCI content were given twice weekly. EC of the nutrient solutions containing 0.25% Volldünger Linz complex fertilizer was made up to 6, 10, 14 and 18 mS/cm, respectively, by 2.51/9.17/17.97/26.76 g/m² doses of pharmacopeal NaCI every week. The solution used for the control treatment contained Volldünger only (EC 4.4 mS/cm). Irrigation was made with pure water (EC 0.6 mS/cm) when necessary.

  The varieties chosen for the experiments were the following: Feherözön, HRF F₁, Syn. Cecei (of white, conical fruit), Boni (of white, blunt, infolded fruit), Titan F₁ (of pointed, hot fruit) and Pritavit F₁ (of tomato shaped fruit).

  In general, the symptoms caused by NaCI treatments (with doses higher than 10 g/m² weekly) have been the following:

  • They have reduced the leaf area, the height of the plants, the total and the early yield, the number of fruit set per square meter, the average weight of the fruit (and, in some measure, fruit length, too) and the thousand seed weight.
  • They have increased the calcium and the chlorine content of the leaves and fruits and the dry matter content of the fruits.
  • They haven't affected the dry matter content of the leaves, the nitrogen, phosphorus and potassium content of the leaves and fruits, and the germinating ability of the seed.
  • The effect on stem diameter and on seed production per fruit has been contradictory in some cases.

  The effects of the intermediate treatments haven't been explicit in several cases.

  The results of the examination of cuticular secretion have indicated the increase of the sodium and chlorine content of the leaves. This can be important in field growing where the rainwater may wash out a part of sodium and chlorine from paprika leaves.

  The hot, pointed variety and the tomato shaped paprika haven't shown clearly higher salt tolerance than the varieties of white fruit colour.

• Evaluation of fruit quality of old apple cultivars originating from the foot of the Carpathian Mountains, for utilization in breeding and in organic farming

  15-24.

  M. Tóth

  E. Balikó

  Zs. Szani

  Views:

  308

  In the frame of the apple breeding program at the Department of Fruit Science old cultivars found in the Carpathian basin were involved in examination as well. Beside testing susceptibility to fire blight (Erwinia amylovora of old genotypes (historical, local and regional cultivars) originating from scattered orchards of Visk (foot of the Carpathian Mountains), fruit quality was also evaluated and other open-field observations were made.

  According to the results of inner content examinations, 'Szemes alma' and 'Sikulai alma', chosen as gene sources for breeding to resistance against fire blight, had inner content values worthy to mention in some aspects, and competing with those of the control cultivar 'Jonathan'. The quality of 'Pónyik alma', also recommended as a gene source is confirmed by the data of earlier literature. Further three cultivars ('Batul', 'Vilmos renet', 'Zöld sóvári') also proved to be good based on resistance against Erwinia amylovora, the first two cultivars are suitable from the point of view of fruit quality, too.

  In our field observations, susceptibility to apple scab and powdery mildew was evaluated. Among cultivars selected from the foot of the Carpathian Mountains on the base of resistance against Erwinia amylovora, the production value of 'Szemes alma' is worsened by its high susceptibility to apple scab. Further selected cultivars ('Sikulai', 'Pónyik alma', 'Batul', 'Vilmos renet') are not too susceptible to fungal diseases and their fruit quality is also suitable, therefore they can be recommended for direct planting in ecological farming or in restoring scattered orchards.

• Structural differences arise between fruit cuticles of two apple cultivars during long term cold storage

  26-29

  R. Oszlányi

  M. Tóth

  L. Szabó

  I. Papp

  Views:

  293

  Apple fruits are covered by hydrophobic cuticle that provides protection against desiccation, pathogens, excessive water absorption and radiation. The features of cuticle affect the quality and storability of the fruits. It was aimed to evaluate the correlation between peel ultrastructure and weight loss in fruits covered by waxy bloom (cv. Florina) and without bloom (cv. Red Rome van Well) during 4-month cold storage. SEM (scanning electron microscopy) was used for visualization of the fruit surface and fruit weight was also measured. Several studies have revealed that there may be correlation between the ultrastructure of cuticle and its water permeability. Our results confirmed this phenomenon in case of two cultivars. The weight loss per fruit surface area unit of ‘Florina’ was found significantly higher than that of ‘Red Rome van Well’. At the same time the cuticular surface of the fruits contained more micro-cracks in case of the former cultivar. These data confirmed the relationship between the density of cuticular micro-cracks and the water vapour permeability. We concluded that this feature is more significant than the amount of natural waxy bloom on fruit surface.

• Evaluation of fruit quality parameters of Rosa taxa from the Carpathian basin

  81-87.

  Sz. Kovács

  M. G. Tóth

  G. Facsar

  Views:

  176

  From the wide range of genetic sources available in Hungary, we have chosen as objective the evaluation of those rose taxa, which — on the base of their quality and morphologic features — are suitable for selecting fruit production varieties or parent varieties for further breeding. We examined physical and inner parameters of fruits of Rosa taxa, and evaluated the correlations by mathematical statistic methods. Namely, if a correlation can be found between physical and inner parameters, fruit production value can be determined by less examinations in the future. According to our results, there is a large variability in some physical parameters (weight, diameter of fruits; weight, number of achenes) as well as in inner content values (vitamin C, glucose, fructose, K, Ca, Fe, Zn and Cu content) of rosehip, regarding production year, habitat and even the individual of examination. Twice as much ascorbic acid can be found in achene-free fruits, and nearly five times as much in their dry product as in fresh whole fruits. It was established repeatedly, that vitamin C concentrates in fruit flesh, and ascorbic acid content can be preserved better in achene-free flesh. There is no essential difference in citric acid and carbo-hydrate content of whole and achene-free rosehips. However, macro- and microelement content of whole fruits is 30-40% higher than that of achene-free fruit flesh. The connection between fresh weight and diameter, as well as achene number and seed weight of fruits can be described by the function y=axb. A significant relationship can be found in case of K-Fe, Ca-Mg, Ca-B, Ca-Mn and Zn-Cu, between fresh weight and B content of fruits. According to our examinations, fresh weight of rose species with a higher citric acid content is usually higher, while their Fe content is smaller. Glucose content of fruits of rose species is directly proportional to their Ca and Zn contents. Zn content of rose species with higher fructose content is usually smaller.

• Anatomical study of the leaves and petioles of scab resistant and susceptible apple cultivars

  53-57.

  M. Tóth

  P. Gracza

  Views:

  192

  Anatomic studies have been performed on the leaf blade, petiole and annual shoot on six apple cultivars by means of scanning electron as well as light microscope. Four of the cultivars examined are resistant to scab (Florina, Freedom, MR-10, MR-11), whereas two of them are susceptible (Jonathan and Idared). Preliminary results suggest that differences in the width of cross sections of leaf blades, in hairyness, in the shape and size of epidermal cells, moreover, in the cross sections of petioles and shoots are considerable. Some of the anatomical properties seem to be correlated with scab resistance or susceptility of the respective cultivars. Therefore, further studies extending to other cultivars may corroborate our claims to find causal relations between anatomical traits of the leaves and disease, especially scab resistance of apple cultivars.

• Changes in germination ability during genebank storage at some medicinal plant seeds belonging to the Solanaceae family

  51-55.

  E. Tóth

  Views:

  131

  In the present work we have examined the changes of germination ability of some medicinal plant species belonging to the Solanaceae family (Datura stramonium L., Datura innoxia Mill. and Hyoscyamus niger L.) during 5-6 years' storage period. According to our results, all the three species showed an after-ripening behavior. Potassium nitrate and gibberellic acid increased significantly the rate of germination in the case of Datura species. During the storage period tested (1995-2001), the species maintained their germination ability which is favourably but not significantly influenced by the cooled gene bank conditions. The degree of ripeness affected considerably the proportion of germinated seeds at all the three species. As a consequence of our results we emphasise that propagation with completely ripe seeds is proposed, however, half-ripe seeds developped in an unadvantageous vegetation period can be also utilized in the practice. The effect of vegetation year on stramony seeds manifested in the length of after-ripening period, while in the case of henbane the germination ability was also influenced.

• 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:

  158

  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.

• Metaxenia in apples cv. 'Rewena', 'Relinda', 'Baujade' as influenced by scab resistant pollinizers

  11-14.

  P. Bodor

  M. Gaál

  M. Tóth

  Views:

  344

  Fruit quality of cross pollinated apples (Malus x domestica) influenced by the metaxenic pollen effect of the pollinizer was observed in Hungary. Flowers of three resistant cultivars (`Baujade', `Rewena') were hand pollinated with other resistant apple cultivars. Fruits were harvested on 25 September, 2005. Fruit quality was investigated in the laboratory of the Department of Pomology; Corvinus University of Budapest. Not only size and morphological parameters (diameter, height, stem length), but also refraction and acidic content of the fruits were measured.

  According to the statistical analysis significant differences were determined on fruits among the groups as an effect of the pollen provider. In consideration of size parameters (diameter, height, weight) of `Rewena' fruits pollination partner 'Freedom' and 'Prima' caused outstanding results but `Florina' caused flatter fruits. Pollen of `Florina' and `Freedor-,' caused a higher percent refraction in the fruits of `Rewena'. In the case of `Baujade' fruits `Reglindis' — among cultivars we used as pollinizer — caused the biggest fruits medium flesh firmness and harmonic inner content values. `Rajka' caused on one hand smaller fruits and on the other hand higher flesh firmness and inner content values in the case of `Relinda' fruits. According to our data measured pollinizers varied the stem length as well.

• N:K ratio and its effect on paprika yield and quality in hydroculture

  35-38.

  Zs. Szepesi

  K. Tóth

  I. Terbe

  Views:

  162

  Earlier results of experiments with paprika grown in soil have shown the high sensitivity of the crop to nutrient supply. According to these findings, yield and also fruit quality are highly affected not only by the nitrogen and potassium level, the concentration of nutrient solution, but also by the nitrogen-potassium ratio. Our preliminary tests have also proved, that the composition of the nutrient solution, first of all, the N/K ratio has a definite effect on the yield quantity and quality. Therefore we have investigated the ratio of the two nutrients with the aim of developing a nutrient solution of optimal composition for white fruited paprika forcing. The most balanced burden of the plants was found when the N/K ratio was 1:1. The highest yield was produced with N/K 1:1.3. Significant yield reduction (30%) was found with the treatment N/K 1:1.9 as compared to the 1:1.3 and 1:1.6.

• Exploring and preserving old apple cultivars of the Carpathian basin

  9-13.

  M. Tóth

  Views:

  184

  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.

• Floral phenology investigation of scab resistant apple varieties and multi-resistant candidates — bred in Hungary — in 2007-2008

  7-10.

  P. Bodor

  M. Gaál

  M. Tóth

  Views:

  204

  Apple (Malus x domestica) is considered practically self-incompatible, polleniser is essential for its economical cultivation. When choosing a polleniser many biological and economical parameters should be taken into consideration. Scab resistant apple varieties and multi-resistant candidates — bred in Hungary — were investigated in our experiment in 2007-2008. Blooming time groups were created according to the overlap of the blooming of the varieties and candidates. Observations were set up in Szigetcsép — the Research Station of Faculty of Horticultural Science. The orchard was planted in 1997. Trees were trained to slender spindle on Rootstock M9. Varieties have been assigned four blooming time groups. 'Reglindis' started blooming in both years. Candidate MR-09 belonged to the early group in 2007 and to the mid-early group in 2008. Latest varieties are 'Freedom' and `Baujade'. Candidate MR-10 belonged to the mid-late group.

• First selections of the Hungarian apple breeding program for multiple resistance

  9-13.

  M. G. Tóth

  Szabó Kovács

  K. Kása

  Zs. Rozsnyay

  M. Hevesi

  Views:

  172

  The aim of the first Hungarian apple breeding program for multiple resistance started in the beginning of the nineties is to widen Hungarian apple assortment by good quality, resistant apple cultivars with excellent productivity and ecological capability to the most important fruit growing areas in Hungary. In the first years of seedling production we made early selection for susceptibility to apple scab in greenhouse. Alter this, field observation of susceptibility to powdery mildew, scab and canker and a yearly negative selection was carried on. From 1997, fruit quality was evaluated as well, and from 2001 the resistance of shoots to Erwinia ainylovora (Burrill/Winslow et al.) was examined using inoculations in greenhouse conditions. From the progenies of crosses in 1992 and 1993, six candidates were announced to national recognition out of hybrids examined for more than a decade. Descriptions of these selections from 'Prima' progenies and the most important data of their resistance, growing habit, morphological characteristics and fruit quality are shown in this article.

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

  47-52.

  M. Tóth

  M. Gaál

  P. Bodor

  Views:

  164

  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.

• Flower visiting activity of honeybees on fruit species blooming subsequently

  12-16.

  M. Soltész

  P. Benedek

  J. Nyéki

  Z. Szabó

  T. Tóth

  Views:

  201

  In the small demonstration orchard of the College Faculty of Horticulture at Kecskemét the blooming time, the flower density and the honeybee activity was observed at a number of cultivars of 20 flower species during four consecutive years.

  Fruit crop species were in flower during 3-4 months altogether. The blooming period of them was classified into five groups as early (almond, apricot, gooseberry), middle early (sweet cherry, red currant, currant-gooseberry, black currant, white currant, peach, plum, sour cherry), middle late (pear, strawberry, apple), late (black elder, quince, medlar, raspberry, blackberry-raspberry) and very late blooming period (blackberry). The blooming period of the members of the groups of early and medium early blooming often coincided partly and the same happened between the medium and the medium late as well as between fruits of late and very late flowering.

  The flower density of some fruit species is extremely variable (currant-gooseberry, medlar), while at others it is fairly stable and evenly dense in consecutive years (sour cherry, sweet cherry, strawberry). At other fruit species it is moderately changeable. Some fruit species tended to attract more honeybees than others (plum, apple, quince, medlar) and some of them tended to attract much less (black elder, pear) but most species can be regarded as of medium attractivity.

  On the flowers of some fruit species (pear, strawberry, quince) honeybees gathered pollen predominantly. At most fruit species however pollen and nectar gathering behaviour seemed to be gradually changing during the season. Namely most honeybees tended to gather pollen at the flowers of the early blooming fruit species, but on the other hand typical foraging behaviour gradually shifted to nectar gathering at the flowers of fruit species of moderate and late blooming periods.

   

• Effect of Erwinia amylovora infection on peroxidase enzyme activity in resistant apple cultivars

  37-39.

  K. Kása

  M. Hevesi

  M. G. Tóth

  É. Stefanovits-Bányai

  Views:

  159

  Two apple cultivars that display enhanced resistance to fire blight (causal agent: Erwinia amylovora) were selected. The aim of the present study was to characterize the peroxidase (POD) enzyme activity of `Szemes alma' (a historical cultivar) and MR-03, (a Hungarian multiresistant hybrid of 'Prima') and compare them to susceptible 'Jonathan M 40' and resistant 'Remo' controls. Peroxides enzyme activity during E. amylovora infections was investigated in artificially infected apple shoots. Increases in enzyme activities were observed in a `Jonathan M40' and in 'Remo', MR-03, `Szemes alma' cultivars. There was a consistent relationship between total enzyme activity and fire blight disease severity. High activity of the peroxidase was positively correlated with the degree of resistance to fire blight. A general hypothesis that POD activity is related to fire blight susceptibility/resistance is supported by our results.

• Frost induced changes in enzyme activities and carbohydrate content in the spurs of some pear cultivars during the dormancy

  41-44.

  K. Honty

  É. Sárdi

  É. Stefanovits-Bányai

  M. Tóth

  Views:

  227

  Frost tolerance of pear cultivars was checked after artificial cold treatment in 2003-2005. Limbs collected during the endodormancy were exposed in a climatic chamber for 24 hours to —25; —28 °C, while those collected in the ecodormancy were kept at —15 and —18 °C. Frost damages of buds were registered according to a visually defined scale, then peroxidase (POD), polyphenol oxidase (PPO) enzyme activities and carbohydrate contents were checked in buds and spur-part below the buds. POD activity of untreated control in tissue below buds was higher than in the buds, which were increasing continuously during the endodormancy and decreased at the end of the ecodormancy. During endodormancy, cold treatment of —25 and —28 °C effected different changes of enzyme activity in buds of the cultivars. In the ecodormancy, enzyme activities increased after a cold treatment of —15 °C, whereas the activities decreased significantly after —18 °C. `Kaiser' — susceptible to frost — with its higher values of both enzyme activities marked out from other cultivars, which is correlated with its stress response. Changes in carbohydrate components — especially in glucose — of buds monitored well the different stress responses of tolerant and resistant pear cultivars induced by frost stress.

• Scab resistance in Malus sp. progenies - inheritance and resistance stability

  9-15.

  M. G. Tóth

  Sz. Kovács

  Zs. D. Rozsnyay

  Views:

  168

  Susceptibility of progenies of some Ma/us species to apple scab was evaluated. Susceptibility of hybrid families was observed first in greenhouse after artificial inoculations by the suspension of the pathogen, Venturia inaequalis (Cooke) Wint., then in open field. The Hungarian type of Malus floribunda, which proved to be scab resistant in our examinations, has a positive effect on the segregation of progenies to resistant and susceptible individuals as a male parent, not depending on the rate of susceptibility of the other parent. However, the German type of Malus floribunda and Malus prunifolia act as dominant, highly susceptible parents.

  Malus x purpurea and Malus baccata, which proved to be highly susceptible to apple scab in open field and in artificial inoculations, transmits its susceptibility only slightly to its progenies as a male parent.

  According to our experiments, the inheritance of scab resistance of Malus floribunda cannot be considered as monogenic, as published by other authors.

  Scab susceptibility of parents influences the segregation of progenies to resistant or susceptible individuals. The moderately scab susceptible `Idared' as female parent has a statistically proved positive effect on the segregation of its progenies.

  More factors indicate the appearance of a new race of Venturia inaequalis (Cke.) Wint.: change of the symptoms in the greenhouse; considerable increase of susceptible individuals after greenhouse inoculation in 1997; more and more progenies of the male parent Malus floribunda became susceptible to scab in open field.

• Chemical communication with volatile semiochemicals in Phyllotreta species (Coleoptera, Chrysomelidae): a minireview

  93-100.

  É. Csonka

  M. Tóth

  Views:

  206

  Phyllotreta species (Coleoptera, Chrysomelidae, Halticinae) rank among the most important horticultural pests in the Northern Hemisphere. Leaf damage caused by flea beetles upsets the water balance, blocks plant growth and sometimes causes a high level of mortality of seedlings. Several species are known to act as vectors of numerous pathogens as well. Chemical communication plays an important role in the host finding, feeding and oviposition behaviour of flea beetles. In the first phase volatile mustard oils (isothiocyanates and thiocyanates) are released from the host plants through the decomposition of non-volatile glucosinolates (chemicals specific to Cruciferae) by myrosinase, and beetles are attracted to the source of release from a distance. Among the isothiocyanates, allyl isothiocyanate is the longest known and widespread compound utilized in the host-plant location of Phyllotreta species, but some species may have a stronger preference to other isothiocyanates or thiocyanates. The attractive effect of the plant volatiles is enhanced by the emission of a male-produced aggregation pheromone. The presence of such a pheromone was first demonstrated in Phyllotreta cruciferae Goeze. In this species R5R,5aS)-1,1,5,8-tetramethy1-1,2,3,4,5,6,5a-heptahydrobenzo[1,2-a][7]annulene] was found to be the main pheromone component. Significant attraction by the pheromone was recorded only in the presence of ALLYL ITCN. The biological activity of the pheromone compound was connected to the plus (+) chirality. The same component seems to be occurring also in the pheromones of several other Phyllotreta spp. as well, suggesting a wider occurence in the genus. Once attracted by the joint effect of plant volatiles and aggregation pheromone, the presence of the non-volatile glucosinolates in the plant tissues is necessary for continuous feeding. Aggregations of flea beetles on suitable host plants, which result from the joint effects of plant-derived and pheromonal chemical cues detailed above may also be good rendez-vous occasions, increasing the probability of encounters with the opposite sex and mating in the vicinity of the optimal oviposition site. Due to the horticultural importance of Phyllotreta spp., deciphering details of their chemical communication has considerable significance in the development of new methods of integrated control.

• Comparison of propagation methods of different moss species used as wall and ground covering ornamental plants

  57-63.

  É. Ónody

  B. Fülöp-Pocsai

  A. Tillyné Mándy

  B. Papp

  E. Tóth

  M. Ördögh

  Views:

  557

  Mosses are traditionally used as ornamental plants, especially in Japan, USA, England (moss gardens) and Germany, French (green roofs). In shadow areas (where the members of Poaceae usually cannot grow well), mosses are potentially use as “grass”. The stocks of moss colonies maintain optimal microclimate and decrease desiccation of soils (like mulch). Additionally, mosses are evergreen, attractive all year, during winter. In our study, 18 moss species were propagated by fragments (as mixture, with the use of 16 species) and transplantation of carpets (with Brachythecium rivulare and Calliergonella cuspidata) in Szentendre. The aim was to find the most durable species and the best way of propagation. In an outdoor, irrigated garden, propagation by fragments was effective (with 63% coveration) and higher values (93% and 76%) were obtained in the cases of non-irrigated stocks of Amblystegium serpens (in trays) and moss carpets. In vertical structures (moss picture-frames with the use of mixtures), protonema of 2 species (Hypnum cupressiforme and Eurhynchium hyans) covered 24 and 33% of the 0.5 x 0.5 m sized area.

• Floral biological investigations of apple cultivars in relation to fire blight

  9-14.

  Zs. Orosz-Kovács

  A. Farkas

  T. Bubán

  P. Bukovics

  E. Nagy Tóth

  H. Déri

  Views:

  180

  Floral activity was studied in two apple cultivars: an Erwinia-tolerant (Treedorn') and a sensitive one (`Sampion'). Since more types of protogyny occur in apples, the period of stigma activity is different. Papillae of the exposed stigma in flowers of 'Freedom' function longer (usually more than a week) than in the delayed homogamous `Sampion'. Despite of this, cv. 'Freedom' is tolerant to Erwinia amylovora (Burr.) Winslow et al., suggesting no relationship between the floral biological type (including the exposure and longevity of stigma) and the infection by E. amylovora. According to SEM micrographs, nectary stomata in `Freedom' are already open in the flower bud, where nectar secretion starts and continues until the senescence of the stigma. However, the long period of nectar secretion does not create optimal conditions for bacterial growth, since nectar production is scant in the flowers of 'Freedom'. The surface of the nectary, its nectar-retaining capacity, and the amount and concentration of nectar may influence the susceptibility of apple cultivars. It is manifested well by the smooth nectary surface with nectary stomata rising slightly above the epidermis in flowers of cv. 'Freedom', contrasting the wrinkled, striate nectary surface with slightly sunken stomata in the flowers of 'Sampion'.

• The inheritance and durability of scab resistance in apple progenies

  39-46.

  M. Tóth

  A. Pedryc

  Views:

  156

  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.