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• The importance of pathogen-free grapevine propagation material in regards to clonal selection and rootstock breeding in Germany

  11-13.

  E. H. Rühl

  F. Manty

  H. Konrad

  E. Bleser

  Views:

  223

  High performing propagation material is essential for a reliable and economical production of quality grapes. Apart from genetic aspects pathogen-freedom is of prime importance in propagation material. In particular virus diseases cause major yield and quality losses and reduced longevity. This is also reflected in the current EU legislation, which focuses on the most common and dangerous viruses: GFLV, ArMV, GLRaV-I and GLRaV-III.Apart from these, locally occurring pathogens, e.g. phytoplasms or agrobacterium, are important as well and should not be present in propagation material. There are several ways to develop pathogen-free clones. Starting with already pathogen-free material is certainly the easiest case, but might not be feasible in local varieties with small acreages and limited vine numbers. In these cases the elimination of pathogens is required, either by heat therapy, tissue culture or somatic embryo genesis.

• Powdery mildew infection dependent on weather factors in vineyards near Keszthely in 2008

  55-59.

  P. Taksony

  E. Tarczal

  K. Maráczi

  I. J. Holb

  L. Kocsis

  Views:

  229

  Weather conditions are extremely influential on grapevine productivity and quality. High temperature and humidity makes favorable conditions for powdery mildew infection respectively. The meteorological data around Keszthely, Hungary show the vegetative period is dryer and warmer than it was closely hundred years ago. We examined the development of powdery mildew infection  on  two variet ies Vitis vinifera L. cv Italian Riesling and cv Merlot in relation with meteorological data. No primer infections were appeared in the vineyard. The year of 2008 was quite ideal for the accumulation of Erysiphe necator in the experimental vineyard. Although the dry summer can lower the infection, but if the high temperature is coupling with rainfall, the possibilities of powdery mildew infection is going to grow higher during the upcoming years.

• Evaluation of different sources of resistance for breeding powdery mildew resistant grapevine varieties

  35-40.

  J. Korbuly

  Views:

  188

  The appearance of resistance to powdery mildew was investigated on seedling progenies of interspecific crossings. Hybrids of American and East-Asian wild species and one Vitis vinifera variety (Janjal kara) were used as source of resistance in the crossings. The resistance of foliage and of berries were tested in the field at the time of vintage. The degree of resistance was ranked into six classes.

  In American and Asian hybrid derivatives there were few highly resistant progenies, but in the hybrids of Janjal kara variety more than 90 % of the progenies proved to be highly resistant to powdery mildew. According to the distribution of classes of resistance in the populations the resistance of American and Asian sources are mostly influenced by additive gene affects. The resistance of Janjal kara seemed to be mono or digenic.

  No close correlation was found between the powdery mildew resistance of the foliage and that of the berries.

   

• Grape rootstock - scion interactions on shoot growth and cane maturing

  30-34.

  L. Kocsis

  Views:

  214

  Interaction between the rootstock and scion varieties (clones) was examined. Berlandieri x Riparia T. K. 5BB, Berlandieri x Riparia T.5C being the most widely used varieties in Hungary, Fercal, Ruggeri 140 being recently used on special soil conditions ; Georgikon 28 a new established variety and Berlandieri x Riparia T. 8B GK 10 clone were the rootstocks used. The V. vinifera L. varieties were a clone of Italian Riesling and two new hybrids from the same cross population f ( Noble Italian Riesling X Ezerjó) X ( Noble Italian Riesling X Pinot Gris ) }. This study presents the results how the growth habit depends on different scion/stock combinations in the first three years.

  Shoot growth characters were observed during the initial years after plantation in the vineyard until we got the first yields. Our results did not agree with those of Pospisilova (1977) that the anticipated vigour of shoot growth will appear later in the vineyard only. However we agree with Zimmerman (1970), who showed that the differences are caused by the rootstocks in the growth habit of vines during the first two years already. The differences in shoot elongation decreased similarly to the rootstocks in the first year of fruit production. It shows us that the intense root development caused vigorous shoot growth, which we think to be a rootstock effect. When the vegetative and generative development are balanced already, the effect of scions in shoot elongation became stronger than the effect of rootstock.

  We also found great differences in the maturation of wood each year from planting of the vineyard to the year of fruit production.

  During the first years the differences of cane maturation were greater according to the scion varieties, the means were significantly different. In the first ripening year the differences dwindled or increased due to the rootstocks. This means that the effect of the rootstock on cane maturation became stronger in the first year of fruit production.

   

• Bacterial diseases of grapevine

  45-49.

  E. Szegedi

  E. L. Civerolo

  Views:

  420

  Grapevines are affected by three major bacterial diseases worldwide, such as bacterial blight (Xylophilus ampelinus), Pierce’s disease (Xylella fastidiosa) and crown gall (Agrobacterium vitis). These bacteria grow in the vascular system of their host, thus they invade and colonize the whole plant, independently on symptom development. Latently infected propagating material is a major factor in their spreading. Therefore the use of bacteria-free planting stock has a basic importance in viticulture. Today several innovative diagnostic methods, mostly based on polymerase chain reaction, are available to detect and identify bacterial pathogens of grapevines. For production of bacteria-free plants, the use hot water treatment followed by establishment of in vitro shoot tip cultures is proposed.