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• Freeze Susceptibility of Fruit Buds in 67 Apple cultivars in Hungary

  29-35.

  M. G. Tóth

  Views:

  147

  Frost damage is one of the most important risks of apple production. Outstanding importance has been attributed to the frost resistance of flower-buds as decisive sites of fruit production. Browning of plants parts and tissues exposed to natural weather adversities are considered as effects of frost. In Hungary, frost damage on flower buds of both the market and new cultivars has not been assessed earlier. Observations referring to the consequences of frost damages of over four critical years, marked by their peculiar winter and spring frost hazards. Parallel observations have been made in four sites of the growing area in the Great-Plain region. 67 apple cultivars have been assessed. Each cultivar was represented by 3 trees, which were sampled at about 1-1.5 m height over ground, where the buds or inflorescences were picked for the purpose to assess the injury. The buds and flowers are cut longitudinally and rated visually according to the extent of browning of the organs and tissues. Susceptibility of different organs of the flower (pistils and anthers) were rated separately. According to our results, most resistant to spring frosts are the following cultivars: 'Gloster', 'Granny Smith' and appreciable tolerance is attributed in 'Gala' and 'Jonathan' with derivatives. Preliminary results that among the scab resistant cultivars, `Baujade', 'Rewena', 'Liberty', `Resi' and 'Renora' are rather frost resistant. Information, lacking hitherto, is obtained upon 'Reka' and 'Reglindis' as for their increased susceptibility.

• Fungicide resistant Trichoderma strains causing compost infection in shiitake production

  67-70.

  Gy. Turóczi

  M. Kovácsné Gyenes

  L. Vajna

  S. Balázs

  Views:

  147

  Trichoderma infection represents the major problem of shiitake production in the growing house of the Research Institute at Kecskemet. Heavy infections occur mainly on the compost before spawn run. All the isolated strain belongs to the species Trichoderma harzianurn, but morphology of the colony indicates that there are more strains liable for the infection. Source of infection remained unclear but the Trichoderma strains can be considered as weed moulds rather than true pathogens of shiitake. All the Trichoderma isolates showed unusual high degree of resistance to fungicides.

• Healthcare values and potential uses of the new Hungarian apple varieties on the basis on fruit analysis

  25-28.

  G. Ficzek

  M. Ladányi

  Zs. Radeczky

  M. Tóth

  Views:

  209

  Biological active compounds and valuable characteristics of some apple varieties and candidates were measured in our trials. Fruits of ’Rosmerta’, ’Hesztia’, ’Cordelia’ and ’Artemisz’ are recommended to enrich the Hungarian assortments for fresh consumption and choice of new tastes. Based on examined parameters it can be assumed that novel Hungarian resistant varieties are suitable for juice and fruit concentrate production, and due to high pectin content of their remaining pomace these varieties can be raw material of pectin production as well as they are also suitable for jam production mixed with other fruit species. Furthermore, functional food industrial product having high quality can be produced by using novel resistant varieties because of their high pectin and polyphenol content. Beside of their high market value their suitability for growing among orchard conditions is confi rmed by lower costs of production because of less plant protection treatments.

• Long term investigations of flowers and leaves on mainly non-domestica plums

  73-79.

  D. Surányi

  Views:

  190

  The author dealt with plum species representing different eco-geographic areas by their genetic adaptation and their hybrids, as European (P. domestica, P. italica, P. cerasifera), Asian (P. salicina, P. simonii, P. ussuriensis), American (P. americana, P. besseyi, P. munsoniana, P. tomentosa). The rootstocks of the trees examined were seedlings of C. 679 myrobalan with the exception of Laroda and Santa Rosa II, which were grown on three different stocks: seedlings of C. 174 myrobalan, C. 449 bitter almond and C. 471 sweet almond. The size of peduncle, length of pistil, stamen number per flower, relative stamen number (SN/PL) have been suitable for description and distinction of varieties. Similarly shape of leaves, length of petiole, length and width of blade helped the identification.

  The ratio of the dimensions of leaves, length of petiole and of leaf blade, also contributed to the distinction of European, Asian and American plum species, notwithstanding their relations with ecological conditions as well as historical, technical properties, pomological features, etc. Computed indicators (relative stamen number and shape-index of leaves) also have been useful data.

  Significant correlations have been found between colour of nectaries and mean values of variety-groups. The potential values of non-European varieties for purposes of commercial production could be forecasted from the point of view of quality, ecological, pomological as well as market value. It is important, however, to know the effect of the rootstock and growing site as well as their interaction, on the one hand, whereas the resistance or tolerance of the varieties as limiting factors, at least to the sharka (Plum pox) virus, Xanthomonas pruni, on the other hand (cf. Surányi & Erdős, 2004a and 2004b).

• Bean tissue culture and genetic transformation with Agrobacterium

  32-35.

  E. Eissa Ahmed

  Gy. Bisztray

  I. Velich

  Views:

  154

  In this paper we report the establishment methods of a rapidly growing callus culture of Phaseolus vulgaris bean as well as the conditions required for a high level of transient gene expression using Agrobacterium-mediated transformation. A vector is containing both the lindan-resistance gene as a selectable marker, and GUS gene as a screenable marker. By using hypocotyl explant and vertical culture on B5 medium supplemented with 1 mg/1 kinetin- and 2,4-D 2 mg/1 and subcultured every 3-4 weeks, we can recommend to get a good and much callus from bean. This will help in introducing foreign DNA into callus cells. One strain of Agrobacterium carrying plasmid as vector for introducing foreign DNA into plant cells was used. At different concentrations of lindan; 3, 4 and 4.5 mg/I, the transformed Maxidor callus survived and grew over a period of 6 month and subcultured every 3-4 weeks, but the control callus died. Callus were assayed for GUS activity to confirm the expression of the GUS gene using the histochemical assay test. The GUS gene was also correctly expressed in callus cultures grown on 4mg/I lindan-selected medium, the typical blue colour in the histochemical assay using the X-gluc as substrate. But the control, non-transformed callus was not able to grow in the presence of lindan, neither showed a positive reaction in the in vitro assays.

• Role of organosilicone surfactant in apple scab control under scab conducive weather conditions

  23-25.

  I. J. Holb

  Views:

  216

  Fungicides of integrated fruit production (dithianon, captan, and diclofluanid) and an organosilicone surfactant were compared in spray schedules from green tip until summer in order to control apple scab caused by Venturia inaequalis and to evaluate their phytotoxicity on fruit. Sixteen sprays of 1.8 kg ha^-1captan, 0.41 ha^-1 dithianon, and 1.8 kg ha^-1 diclolfluanid significantly (P=0.05) reduced the incidence of leaf or fruit scab compared to unsprayed products. All fungicides applied with organosilicone at 0.1% resulted in lower incidence of scab on young and older leaves as well as on harvested fruit, but these were not statistically always better than fungicides applied alone. In case of diclofluanid, the fungicide applied with organosilicone at 0.1% resulted in significantly lower (P = 0.001) incidence of scab on young and older leaves. Diclofluanid applied with organosilicone at 0.1% gave the best scab control on leaf and fruit. Treatments applied with fungicides alone had no significant effect on plant phytotoxicity compared to untreated control. All fungicides applied with organosilicone at 0.1% increased (P = 0.05) fruit damage compared to untreated control or fungicide applied alone, though these were not always significantly different. In case of percentage of fruit russet, treatment of dithianon 0.4 1/ha + 0.1% organosilicone significantly increased fruit russet, while fruit russet index significantly increased in the treatment of diclofluanid 1.8 kg/ha + 0.1% organosilicone compared to untreated control. In sum, application of surfactants can help to increase efficacy of scab fungicides; and consequently, to reduce the risk of fungus infection under high scab disease pressure. This fact may also be helpful in fungicide resistance management and reduced-spray programs with accurate scab warning systems.