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• Sunburn assessment: A critical appraisal of methods and techniques for characterizing the damage to apple fruit

  7-14.

  J. Racskó

  Views:

  857

  Many methods and techniques have been introduced for measuring alterations in the fruit and in its surrounding environment related to sunburn incidence. The research objectives, fruit materials and the environment to be evaluated dictate the methods to follow. These procedures are either non-destructive and involve techniques that allow us to track the course of sunburn development and related environmental parameters, or destructive and involve the removal of fruit from the tree for field/laboratory measurements. Techniques employed can be used for pre-symptomatic monitoring (before symptoms become visible) or characterizing the symptoms already present. The principles behind the measurements and their usefulness for sunburn assessments are discussed and critically evaluated in this review paper. Descriptions and evaluations of the methods and techniques were made in the following groups: 1. Thermal measurements; 2. Visual assessments; 3. Fruit quality measurements; 4. Measurements of physiological and biochemical alterations; and 5. Practical evaluation of sunburn damage. Thermal measurements involve methods tracking the ambient temperature and fruit surface temperature, and their relation to sunburn formation. Visual assessments cover all measuring techniques (skin color, chlorophyll fluorescence, radiation reflection, electron microscopy) that are able to detect changes on/in the fruit skin related to sunburn formation. Fruit quality measurements are used to point out differences in qualities (soluble solids, firmness, titratable acidity, and water content) between unaffected and sunburned areas of the fruit. The measurements of physiological and biochemical alterations (gas exchange, pigment analysis, enzyme activity, gene expression) give us a better insight to the mechanism of sunburn formation. Practical evaluations involve many procedures that are used by scientists to characterize the susceptibility of cultivars, evaluate protection technology, etc. For this purpose, the following methods are in use: expressing the percentage of the total fruit surface area affected by sunburn or the percentage of the total number of fruits damaged on the tree, or even a scale based on the severity of the symptoms occurred. All assessing methods and techniques described here have their pros and cons as well as their specific applicability, therefore any of these cannot be favored to use exclusively for assessing sunburn incidence. The combination of these techniques will be the best choice to meet a given research objective perfectly.

• Aminoglycoside antibiotics affect the in vitro morphogenic response of chrysanthemum and tobacco

  93-104.

  Da Silva Teixeira

  S. Fukai

  Views:

  245

  Broadly the success of genetic transformation of plants requires non-chimeric selection of transformed tissues and its subsequent regeneration. With rare exceptions, most plant transformation protocols still heavily utilize antibiotics for the selection of transgenic cells containing an antibiotic-degrading selectable marker gene. The morphogenic capacity of in vitro chrysanthemum and tobacco stem and leaf explants change with the addition of aminoglycoside antibiotics (AAs). Of 6 antibiotics tested, phytotoxicity occurred at 10-25 and 50-100 pgml^-I in chrysanthemum and tobacco explants, respectively, depending on the size of the explant and the timing of application. The presence of light or darkness also had a significant effect. The use of transverse thin cell layers (tTCLs) in conjunction with high initial AA selection levels supported the greatest regeneration of transgenic material (adventitious shoots or callus) and the lowest number of escapes. Flow cytometric analyses demonstrate that regeneration can be predicted in both species, depending on the ploidy level of the callus. Endoreduplication was not observed in chrysanthemum, even at high AA levels, but occurred (8C or more) in tobacco callus, even at low AA concentrations (5-10 pgml^-1). The higher the AA level, the greater the DNA degradation and the lower the 2C and 4C values.

• Historical apple cultivars that display high level of resistance to fire blight

  19-23

  K. Kása

  M. G. Tóth

  M. Hevesi

  Views:

  345

  Following the first outbreak of fire blight caused by the bacterium Erwinia amylovora (Burrill) Winslow et al. in Hungary, we have started research with the aim to screen domestic gene sources, mostly historical Hungarian apple cultivars, for disease resistance as part of an apple breeding program for multiple resistance. The present study was conducted with the aim to choose the most tolerant historical apple cultivars among 25 selected cultivars by screening their behavior towards fire blight under controlled conditions. Six cultivars were shown to be the most disease tolerant: `Batul', 'London pepin', Nemes Sóvári Alma', `Sikulai', `Szemes alma', Wilmos renet'. We evaluated these cultivars by investigating both morphological- characteristics under original environmental circumstances and fruit quality. The cultivars had a remarkable degree of fire blight resistance compared to the control cultivars. These were not competitive with the commercially grown 'Jonathan M40' during cultivar tests but on the basis of certain characteristics they could serve as genetic sources for breeding new varieties.

• Studies on the Tobamovirus resistance of the pepper (Capsicum annuum L.) cultivar Greygo

  71-75.

  P. Salomon

  G. Venczel

  Views:

  267

  Resistance of the Hungarian pepper (Capsicum annuum L.) cultivar "Gre_.ygo" to Tohamoviruses has been investigated. All plants of the population of Greygo proved to be resistant to tobacco mosaic and tomato mosaic viruses (TMV, ToMV), both represent the pepper pathotypes P_o of Tohamoviruses. Individuals of Greygo, however, were found to be susceptible to pathotypes P₁₂ and P₁₂₃ of pepper mild mottle virus (PMMV). When inoculated with the XM isolate of dulcamara yellow fleck virus (DYFV, pathotype P1) the population of Greygo segregated in resistant and susceptible plants. These results as well as inoculations of the progenies of three TMV resistant plants clearly showed, that besides the resistance allele Li the cultivar Greygo possesses also an another allele. This allele, provisionally marked by L²g behaves like to the allele L² characteristic to Capsicum frutescens cv. . Tabasco. Determination of the identity of the allele L²g to the allele L² needs further genetic and pathological informations. Relations between the Tohamoviruses pathogenic to pepper and the alleles of the resistance gene L are outlined for the discussion.

   

• Evaluation of introduced plum varieties under extreme climatic conditions

  7-10.

  D. Surányi

  Views:

  560

  In the gene bank variety collection, 15 plum varieties were examined based on morphogenetic and pomological traits. Most cultivars of self-fertilizing or pollinating partners were well-cultivated. In addition to Queston, Stanley, Valor and Verity, towards 11 new cultivars have been experienced in this paper.

  From the observations, it seems that the growth and plantation of Valor, Presenta, Topfive and Bellamira can increase. However, the Top Sugar and Valor fruit sizes are best suited to market requirements. The role of Stanley may be reduced, but there is no reason to replace it. However, the questions of local varieties of domestic origin fall into a different category, and raw materials for quality products are difficult to replace with other varieties.

• Six promising selections from the Hungarian apple breeding program for multiple resistance

  23-28.

  M. Tóth

  Views:

  363

  An apple breeding program has been carried out at the Department of Fruit Science for more than a decade. Several apple selections have been released from the progenies of crosses in 1992 and 1993. Six candidates were submitted for national recognition out of the hybrids examined for more than a decade. The six selections are resistant against all the three most important apple diseases (apple scab, powdery mildew and fire blight). Scab resistance is controlled by the Vf gene originating from the species Malus floribunda 821 and transmitted by cultivar Prima. Heterozygote Vfvf genotype of the six cultivar candidates was proved by molecular genetic examinations of Dept. Genetics and Plant Breeding. Characteristics of these selections from 'Prima' progenies are shown on the base of our own observations.

• In vitro plant regeneration from immature embryo axis and cotyledons of common bean (Phaseolus vulgaris L.)

  93-97.

  H. Eissa Ahmed

  Views:

  240

  Phaseolus vulgaris L. is the most important economic species within the genus Phaseolus. It is grown in all parts of the world. Genetic improvement by conventional breeding has met considerable success, although production of hybrids between species within the genus has been limited due to sexual incompatibility. Recent advances in tissue culture have offered the opportunity to produce cultivars, which could not be obtained by conventional breeding methods. The use of tissue culture and genetic engineering is viewed as a logical approach to improve bean production. Gene transfer techniques will have a great impact on legumes. Although the concept of cell totipotency is widely proved, in vitro morphogenesis has not yet been achieved for a large number of cultivated beans. Regeneration protocols are strongly influenced by the genotype. In tissue and cell culture of beans, the factors controlling shoot morphogenesis and somatic embryogenesis are still unknown. The reported data suggest a possible way for future research.

• Results in table beet breeding (Review)

  15-18.

  M. Takácsné Hájos

  Views:

  339

  Results in table beet breeding (Review)

• Evaluation of Colour Versions of Wild Sage (Salvia nemorosa L.)

  111-115.

  T. Kaprinyák

  J. Koronkai

  A. A. Zsiláné

  Gy. Szakadát

  P. Lévai

  Z. Kováts

  M. Fári

  Views:

  500

  In the continental weather zone, more and more frequently occurring extreme conditions require continuous renewal of the market which generates constant challenge for the ornamental plant breeders. Most of the traditionally used decorative ornamental plants are sensitive to these extreme conditions. In 2001, Department of Plant Biotechnology, Debrecen University initiated an interdisciplinary breeding program in collaborations with Zoltan Kovats (he dealt with hungarian drought-tolerant plant species) to produce new or reintroduce forgotten drought-tolerant ornamental species into public parks and roadsides. From ~900 species of Salvia genus, Salvia nemorosa L. has been known as a medical plant, however, because of its high adaptation ability and decorative nature it is a highly recommended ornamental plant as well. Salvia nemorosa L. has a low maintenance, extremely droughttolerant, fast growing plant, generates proper cover, and highly competing weeds on roadsides. Nowadays, 50-60 varieties are available; however this number could be increased by new hybrids. Great morphological and colour variation could be seen within the species, from different white to deep violet. The main goal of this research is the production of elite lines with wide colour and morphological variation in wild sage. We have already obtained 25 different clones for further investigation without eliminating the original plants generating an in vitro gene bank as it has been done by Italian breeders.

• Incompatibility studies of Hungarian sweet cherry (Prunus avium L.) cultivars by traditional test crossings

  43-47.

  Zs. Békefi

  Views:

  261

  Cross-incompatibility is a common phenomenon between various sweet cherry (Prunus avium L.) cultivars. Traditionally, choosing cross-compatible cultivar pairs is based on test crossings in the field.

  There is a lack of information about fertility relations of novel Hungarian sweet cherry cultivars and selections. We have studied cross-incompatibility in 42 sweet cherry cultivar pairs by test-crossings in the field. Out of those, 3 combinations showed incompatibility and 15 pairs were compatible.

  Test-crossing results proved that with the knowledge of S-allele constitution of Hungarian cultivars incompatible cultivar pairs are recognised in practice reliably. However, we assume that in sterility not only the S-gene system, but other factors (e.g. abnormal development of pollen or flower) also occur, therefore, their examination would be needed.

• Relationship between several meteorological factors and phenological features of apple cultivars

  13-19.

  L. Lakatos

  T. Szabó

  S. Zhongfu

  Y. Wang

  J. Racskó

  Z. Szabó

  M. Soltész

  J. Nyéki

  Views:

  1256

  The trees observed are grown at Ofeherto, Eastern Hungary in the plantation of an assortment (gene bank) with 586 apple cultivars. Each of the cultivars were observed as for their dates of subsequent phenophases, the beginning of bloom, main bloom and the end of bloom over a period between 1984 and 2001. during this period the meteorological data-base keeps the following variables: daily means of temperature (°C), daily maximum temperature (°C), daily minimum temperature (°C), daily precipitation sums (mm), daily sums of sunny hours, daily means of the differences between the day-time and night-time temperatures (°C), average differences between temperatures of successive daily means (°C). Between the 90^th and 147^th day of the year over the 18 years of observation. The early blooming cultivars start blooming at 10-21April. The cultivars of intermediate bloom start at the interval 20 April to 3 May, whereas the late blooming group start at 2-10 May. Among the meteorological variables of the former autumnal and hibernal periods, the hibernal maxima were the most active factor influencing the start of bloom in the subsequent spring.

• Production of transgenic carnation with antisense ACS (1-aminocyclopropane44-carboxy late synthase) gene

  104-107.

  E. Kiss

  A. Veres

  Zs. Galli

  N. Nagy

  E. Tóth

  Á. Varga

  G. Hrazdina

  L. Heszky

  Views:

  456

  Dianthus chinensis and Dianthus caryophyllus varieties were tested for shoot regeneration from leaf and petal explants and transformed with Agrobacterium tuniefaciens strains (EHA 105 and LBA 4404) harbouring an apple derived ACS cDNA in antisense orientation in order to reduce ethylene production and influence the ethylene dependant traits in carnation. After transformation regenerating shoots were selected on MS medium containing 50-75-100-125-150 mg/1 kanamycin and supplemented with 1 mg/1 BA, 0.2 mg/1 NAA. Transgene integration was proved by PCR analysis with npt II spcific primers followed by Southern hybridisation of DNA isolated from green shoots on medium containing 150 mg/1 kanamycin. Several putative transformants were subjected to RT-PCR in order to examine the npt 11 expression at mRNA level. Both the transformant and the non-transformant plants were potted into glasshouse to observe the effect of changed ethylene production on flowering time, petal senescence and vase life.

   

• Historical background and constraints of a grapevine germplasm foundation in Hajdú-Bihar county, Eastern Hungary

  11-17.

  N. Rakonczás

  Views:

  462

  The historical background of Debrecen linked to viticulture and wine-making stands mainly on the lack of drinkable water, the necessity of drinkable liquid during wartime and epidemics. The special character of the city evolved together with the changing lives of citizens and the increasing trade importance of the city. Period of Turkish occupation gave impetus to the formation of the 11 vine gardens of the settlement. After the devastation of rootmite and peronospora ‘Kadarica’ and ‘Nagy burgundy’ (‘Blaufrankish’), in smaller proportion - on lower sites – ‘Cabernet’ were planted. As white varieties ‘Ezerjó’, ‘Olasz Rizling’, ‘Kövidinka’, ‘white Mustos’, in smaller proportion ‘Szlankamenka’, ‘Erdei’, ‘Szilvaner’, ‘Mézesfehér’, ‘Bakar’, ‘Veltelini’ (red), ‘Fehér burgundi’ (? white burdunder), ‘Rajnai rizling’, ‘Red Tramini’, ‘Furmint’, ‘Muscat Lunel’, ‘Járdovány’ and ‘Juh-fark’ were planted. After the Trianon treaty in 1920, 2/3rd of Hungary was cut away. Érmellék wine region was also cut in two, thus Debrecen broke away from its wine region. Legal regulations after the World War II. (1959) referred back to variety application advised in 1924 for “place suitable for good wine production, not included in any wine region”, like Debrecen listing ’Ezerjó’, ’Mézesfehér’, ’Olaszrizling’, ’Bánáti rizling’, ’Furmint’, ’Hárslevelű’, ’Kövidinka’, Kecskemét virága’, ’Piros szlankamenka’,’Pozsonyi fehér’; ’Kadarka’, ’Oportó’ and ’Kékfrankos’ (Blaufrankish). The political changes of 1990 and Hungary’s admission to the Eurepoean Union almost annihilated the wine production of Debrecen. However little gardens conserved historic varieties which could date back even to many centuries. Through a local magazine a collecting work was announced pointing to gather ancient local (Vitis vinifera conv. pontica) varieties forming a genebank, established on the experimental station of the University of Debrecen. In 2014, about 112 items were collected (accessions). As a 2nd round of the work, with a more detailed and precise work, further 81 items were put into the reservatum. The latter represent single stuck collection, whereas the first ones are to be studied az mixed items. Most notable accession names (ACENAME) of the work are: ‘Fehér gohér’, ‘Veres gohér’, ‘Fekete gohér’, ‘Kék gohér’, ‘Erdei’, ‘Ezerjó’, ‘Kűbeli’, ‘Rizling’, ‘Mézes fehér’, ‘Dinka’, ‘Madling’, ‘Bakator’ and ‘Kadarka’. Simulteneously with the strenghening and morphological description of conserved stucks genetic identification of the items is being elaborated. Database comprising FAO/IPGRI multi-crop passport descriptors and OIV Primary descriptor priority list are to be published on-line in between the development of the platform.

• The Hungarian pear germplasm as source of genetic variability for breeding programmes

  7-13.

  T. Szabó

  I. F. Labuschagne

  S. Musacchi

  J. Nyéki

  J. Tornyai

  M. Soltész

  Z. Szabó

  Views:

  1110

  TheHungarian pear collection (Pyrus communis L.) consists of 423 genotypes distributed over seven genebanks inHungary. This is one of themost extensive collections of native and cultivated pears found in Eastern Europe and includes a wide range of genotypes with small size fruit (referred to as “Miniature pears”). Based on the in situ and ex situ measures taken by governmental and other institutions for fruit tree conservation in Hungary, an overview is given on some activities regarding areas of Pyrus collection and genebanks where pears are collected and grown. Descriptions of traits of miniature pears found in Hungarian genebanks for the interest of genetic characterization and breeding are presented.

• The importance of Hungarian melon (Cucumis melo L.) landraces, local types and old varieties (Review)

  83-87.

  Cs. Szamosi

  Views:

  316

  While supermarkets devote whole aisles to hybrids, traditional varieties are hard to find, and becoming scarcer day by day. Unfortunately, countless old melon varieties have already been lost. Luckily we succeded in collecting most of these varieties, and thus conserving them in Gene Banks. Landraces, local types, and old breed races show many characteristics that could be useful in organic farming. It is important to get acquainted with these varieties and cultivars, because they have greatly adapted to the climatic and pedological conditions of the Carpathian basin. Therefore their conservation is essential for the protection of Hungarian genetic variability. With the help of utilising our landraces in organic farming; careful selection; and the usage of marketing strategy in order to enhance quality features, such as unique flavour; we could reclaim the one-time excellent reputation of Hungarian melon.

• Reactions of some cucumber (Cucumis sativus L.) lines and hybrids to zucchini yellow mosaic virus (ZYMV) and selection of tolerant breeding lines

  66-68.

  P. Salamon

  P. Balogh

  Views:

  342

  In the past years zucchini yellow mosaic virus (ZYMV) has been appeared as a new pathogen of cucurbitaceous plants in Hungary. It caused severe disease outbreaks on the fields of pickling cucumber hybrids which are highly tolerant to cucumber mosaic virus (CMV). Preliminary inoculation tests have showed that all of the important pickling cucumber hybrids produced in Hungary were susceptible to ZYMV-P. However, a selection of Chinese Long and the breeding line I- KS 10C proved to be highly tolerant. The Fl plants of the crosses between the tolerant lines and the susceptible genotype H I were susceptible to ZYMV-P. F2 populations segregated for susceptible and tolerant individuals at a ratio of 3:1. The results strongly suggest that the resistance to ZYMV in our sources is controlled by a single recessive gene. Inoculations of the ZYMV and CMV susceptible cultivar Budai csemege and the CMV tolerant hybrid Perez Fl with the complex of ZYMV+CMV resulted extremely severe symptoms (strong mosaic and necrotic spotting of the leaves) on both cultivars. On the Chinese Long line, which is tolerant to ZYMV and CMV, respectively, the complex of the two viruses caused mild symptoms. The results show a synergistic pathological effect of ZYMV and CMV on differrent cucumber genotypes. More detailed studies on the interactions among the plant genotypes, viruses and virus strains are needed to develop cucumber hybrids that are highly resistant to the ZYMV+CMV complex.

• Relations of phenometrical indices of apple fruits with weather variation in the assortment of varieties of an apple gene bank

  115-120.

  L. Lakatos

  T. Szabó

  Z. Szabó

  M. Soltész

  Z. Sun

  J. Nyéki

  Views:

  1233

  The purpose of phenometry is to examine the measurable parameters of the plants in order to follow up the consequences of weather processes. We should fi nd the reasons, why the diameter of fruits grows larger in one season and smaller in the next. Variation may occur as a response to insuffi cient provision of water or nutrients, but also because of pathological effects and of extremely high or low temperatures, moreover, of extraordinary heavy fruit load. There are phenometrical characteristics, which consider the fi nal consequences (density of fl owers, fruits set, drop of fruits), whereas other parameters could be followed up (size, length and width of fruits) as the dynamic components of growth. The quantitative parameters of growth are functionally related to each other, where the weather conditions, soil humidity and nutrients are on the input side, thus it is possible to model the growth of fruits as a function of the environment. Initially, the relations between the main weather variables and the phenometrical data have to be cleared. In the present study, the interactions between the mentioned phenomena are presented and numerically defi ned.

• Transmethylation and the general defense reaction of plants

  35-40.

  E. Szarka

  E. Sárdi

  G. Csilléry

  J. Szarka

  Views:

  409

  Plant breeding for resistance, namely building specific resistance genes into cultivated plants to ensure resistance against certain pathogen species, is a several-decade-long practice. While looking for purposes of failures appearing during the cultivation of varieties created in this way, a plant feature that ensures non-specific reactions against effects which evoke biotic stress attracted our attention. We named this plant defense form the general defense reaction. The general defense reaction is a fundamental attribute of the plant kingdom, fulfils the role of plant immune system and manifests itself in cell enlargement and cell division. Plants with a high level general defense reaction endure abiotic stresses as well.

  In studying the biochemical background of the interaction of the general defense reaction and transmethylation, we found that transmethylation has important role in warding off both biotic and abiotic stresses. According to our observations, plants possessing high level general defense system are suitable for thorough examination of the process and plant physiological role of transmethylation. Biochemical studies also strengthened our observation, which has been taken on the basis of phenotype, that the general defense system can not be ignored during future plant breeding.

• Controlling the southern root-knot nematode (Meloidogyne incognita Chitwood) with grafted and resistant pepper varieties

  33-37.

  Z. Mándoki

  Views:

  353

  Newly bred resistant bell pepper varieties and those grafted onto resistant rootstock s were tested in soil severely infested with southern root-knot nematode [Meloidogy11e incognita (Kofoid and White) Chitwood] in unheated plastic house and compared to varieties on their own roots, in order to evaluate the efficiency of this environmentally friendly control method. 'Cinema F I ' carrying the N gene yielded significantly more than the two susceptible varieties. Varieties grafted onto resistant rootstocks outyielded those on their own roots although to different extent, which was not always significant. At the end of the vegetat ion period the roots of the rootstocks were undamaged and the roots of some resistant varieties were slightly infected. whereas the roots of susceptible varieties were severely damaged. According to our result  . both the use of resistant varieties and grafted plants offer an effective and environmentally safe way of controlling M. incognita.

• Inheritance of male sterility in apricot

  12-14.

  L. Burgos

  J. Egea

  Views:

  240

  Progenies (total of 1,114 seedlings) from crosses representing all possible genotypic combinations between 4 male-fertile and 1 male-sterile apricot parents were scored for the male sterility trait. Crosses between putative heterozygous normal cultivars yielded 25% of male-sterile seedlings, which supports a previous hypothesis that male sterility is controlled by a recessive allele of one nuclear locus. Crosses between those parents and putative homozygous normal cultivars did not produce any male-sterile tree. Finally, the proportion of male-sterile progeny in crosses between a male-sterile and two male-fertile cultivars depended on the genotype of the male parent. When it was heterozygous approximately 50% of the progeny was sterile, whereas when a homozygous fertile parent was used, no male-sterile progeny was obtained. These results confirm a previously proposed model, in which the male sterility trait in apricot is controlled by a single recessive gene.

• The Effects of Some Parameters on Agrobacterium-Mediated Transformation in Muskmelon

  46-49.

  Z. Qiu

  Cs. Bársony

  Gy. Bisztray

  I. Velich

  Views:

  417

  Some parameters involved in Agrobacterium-mediated transformation in muskmelon Hales best (HBS) were studied. Cotyledon explants excised from 3.5-day-old seedlings were co-cultivated with Agrobacterium tumefaciens harbouring binary vectors which contained GUS and BAR genes. After co-cultivation on a low pH medium, explants were transferred to selective medium, with higher pH, containing Claforan and Finale. The medium was changed every two weeks till shoots were induced. All shoots rooted on MS medium supplemented with 0.3 mg/L IBA. These parameters combined as a whole led to successful transformation. The expression of the introduced gene construct was confirmed by GUS staining of shoot segments.

   

• Relationship between several meteorological factors and phenological features of pear cultivars

  67-73.

  L. Lakatos

  T. Szabó

  G. Kocsisné Molnár

  J. Racskó

  M. Soltész

  Z. Szabó

  J. Nyéki

  Views:

  1452

  The aim of this paper was to investigate the fl owering characteristic of apples and their relationship to meteorological parameters. The trees observed are grown at Újfehértó, Eastern Hungary in the plantation of an assortment (gene bank) with 586 apple varieties. Each of the varieties were observed as for their dates of subsequent phenophases, the beginning of bloom, main bloom and the end of bloom over a period between 1984 and 2001 during this period the meteorological data-base keeps the following variables: daily means of temperature (°C), daily maximum temperature (°C), daily minimum temperature (°C), daily precipitation sums (mm), daily sums of sunny hours, daily means of the differences between the day-time and night-time temperatures (°C), average differences between temperatures of successive daily means (°C). Between the 90th and 147th day of the year over the 18 years of observation. The early blooming varieties start blooming at 10–21April. The varieties of intermediate bloom start at the interval 20 April to 3 May, whereas the late blooming group start at 2–10 May. Among the meteorological variables of the former autumnal and hibernal periods, the hibernal maxima were the most active factor infl uencing the start of bloom in the subsequent spring.

• Selection of the chance seedlings of `Mézes körte' (Pyrus communis L.) from the gene bank of Keszthely

  21-27.

  J. Varga

  J. Iváncsics

  G. Kocsisné Molnár

  J. Nyéki

  Views:

  936

  We have concluded the selection tests of the `Mézes körte' seedlings planted in the spring of 2006, with special emphasis on the cotyledonary, foliage leaf and the height of plant. Out of the 75 seeds planted in rows, there were 40-45 pieces growing out, so during the first cotyledonary test we had to calculate with almost 40% decay. On 12th April 2006, we recorded some of the important characteristics of the seedlings in their cotyledonary stage which characteristics were important from the point of view of selection (cotyledonary form, cotyledonary length, cotyledonary thickness, cotyledonary colour, cotyledonary petiole length, cotyledonary petiole thickness, cotyledonary petiole colour). The above morphological characteristics are shown in Table No. 1-6. We have also tested the seedling in foliage leaf state, paying special attention on the development stage of the plants (colour of foliage leaf , height of plant). We have completed statistical calculations of the two above mentioned characteristics. The result of that is summarised in Table No. 8-9. The variation coefficient show smaller value in the case of the foliage leaf number (15-32%), while the wider range of spread of the data referring to the height of the plant is shown by the 33-61% CV values. On charts No 4-9. we present the relationship between the height of the plant and the number of foliage leaf, as well as the differences between the two graphs. Based on the above charts and graphs it can be defined that the 40% destruction of the developing seedlings during the period till the next measurement reached 70-80% level. In spite of this however some seedlings showed strong and balanced growth (A₄₄, B₄₂, C₂₅, D₁₆, E₅, E₃₉, F₃₈), the further testing and selection of those is to be completed in the future.

• Self fertility of pear varieties conditioned by natural self pollination (autogamy)

  110-113.

  J. Nyéki

  M. Soltész

  J. Iváncsics

  Views:

  1320

  Authors studied the autofertility depending on natural self pollination (autogamy) in 59 pear cultivars during 4 seasons at three locations with different ecological conditions (Helvetia, Kecskemet-Kisfai, Keszthely). The aim of the experiments was to determine the autogamous tendencies of varieties hitherto unexplored in the Hungarien gene bank, or to check data found in the literature. A total of 42616 isolated pear flowers produced 1.2% fruits with at least one viable seed in each. The 59 varieties observed did not set fruit by autogamy on either of the three sites during the four years of the study. The triploid (3n=51) varieties were entirely self-sterile. According to the highest autogamous fruit set, during the experimental period, the varieties have been assigned to four groups: (1) Entirely auto-incompatible (0% fruit set), (2) auto-incompatible (0.1 to 0.9%), slightly self fertile (1.1 to 5%) and (4) self fertile (5.1 to 10%). According to the number of viable seeds per fruit resulting from autogamy, the varieties are assigned to three groups as (1) low seed content (less than 3 seeds per fruit), medium (3.1 to 5) and (3) high (more than 5 seeds). Thus, the assessment of the number of seeds per fruit resulting from autogamy is indispensable as a proof of the absence of parthenocarpy.

• Induce the plant resistance to pathogen infection

  89-93.

  A. Ezzat

  Z. Szabó

  J. Nyéki

  Views:

  1494

  Systemic acquired resistance (SAR) is a mechanism of induced defense that confers long-lasting protection against a broad spectrum of microorganisms. Salicylic acid (SA) is the signal molecule which is required for induce SAR and is associated with accumulation of pathogenesis-related proteins, which are thought to contribute to resistance. SA paly vital role in some related resistance gene expression in plant cell which have direct or indirect effect on pathogen growth as SA has direct toxicity for pathogen and in the same time has stimulation effect for some enzyme related to reduce the oxidative burst.