The introduction of rootstocks marks the first biologic pest control and at the same time the beg... more The introduction of rootstocks marks the first biologic pest control and at the same time the beginning of modern viticulture. Since then problems with unsuitable soil conditions may be overcome by using better adapted rootstocks. Despite this option, the number of rootstocks is still rather small and worldwide about half a dozen rootstocks are planted on approximately 60% of all sites. New soil born pests or diseases adapted to them could spread easily, repeating the phylloxera disaster. To overcome this threat more genetic rootstock diversity is needed. This task requires more new rootstocks, but also more knowledge about site adaptation of new and already existing varieties. Rootstock trials take 10 to 20 years and should be conducted on typical sites and usually private vineyards. This results in a number of restrictions regarding block size, replicates, number and kind of rootstocks being used. Despite these restrictions, such trials still provide valuable information on rootstock characteristics and site suitability. Results indicate that both already existing underutilized rootstocks, as well as recently developed hybrids with a complete phylloxera resistance mechanism, are suitable on many locations in Germany and provide the chance to enlarge genetic diversity in rootstocks and utilize site potential by better adapted rootstocks.
Monoterpenes are considered to be one of the major classes of volatile flavour components in many... more Monoterpenes are considered to be one of the major classes of volatile flavour components in many grapevine cultivars and are characteristic of fruity and floral white wines. The purpose of this study was to compare seasonal variation in monoterpene levels of different grape cultivars and characterise metabolic pathway genes leading to monoterpene production. Grape cultivars with different aromatic attributes (high to low aroma) and non-aromatic cultivars were collected at different stages during several seasons from our experimental vineyard in Geisenheim. Monoterpenes were extracted using solid phase extraction (SPE) and analysed by GC/MS. This study focused on major monoterpene alcohols linalool, geraniol and α-terpineol. In this study putative grape monoterpene synthase genes from several cultivars were sequenced and their potential for marker-assisted breeding assessed.
By parasitizing the roots of Vitis species, grape phylloxera (Daktulosphaira vitifoliae Fitch, Ph... more By parasitizing the roots of Vitis species, grape phylloxera (Daktulosphaira vitifoliae Fitch, Phylloxeridae) is one of the most devastating pests in viticulture. Grafting susceptible scions (Vitis vinifera) to tolerant Vitis rootstocks is a common practice to control grape phylloxera in wine growing regions worldwide. However, grape phylloxera populations still develop on the roots of most grafting combinations. Questions remain as to whether or not the impact of environmental factors on grape phylloxera population dynamics is related to Vitis rootstock cultivars. In the presented field study, we investigated the influence of two closely related mature Vitis berlandieri x Vitis riparia rootstock varieties on the relations between the dynamics of root feeding grape phylloxera populations, root morphology and abiotic factors. The investigation took place on a commercial vineyard in Geisenheim/Germany on Teleki 5C/V. vinifera 'Weisser Riesling' and Kober 125AA/V. vinifera '...
Australian Journal of Grape and Wine Research, 2016
Background and Aims Daktulosphaira vitifoliae Fitch (grape phylloxera, Phylloxeridae) is one of t... more Background and Aims Daktulosphaira vitifoliae Fitch (grape phylloxera, Phylloxeridae) is one of the most devastating pests in viticulture, mainly because of their root feeding activity. Up to today fundamental relations between belowground habitat and population dynamics remain unclear. In this 2-year study, we investigated the relations between grape phylloxera population and phenotypic traits of roots and feedings sites. Methods and Results We extracted root and soil samples frequently of two closely related mature rootstocks [Vitis berlandieri × V. riparia (cvs 5C and 125AA)]. We quantified and characterised larval population and crowding and assessed root gall pigmentation, root morphology and soil parameters. We identified and described three stages of seasonal population dynamics: reproduction, overwintering and declining. Further, we demonstrated a significant impact of root gall pigmentation and crowding on population dynamics. Conclusions In temperate climates, grape phylloxera is able to overwinter at high density on roots of American rootstocks. Population dynamics are highly dependent on root gall development and the ability to crowd. Significance of the Study The results of our study are considered to have a significant impact on the development of management strategies for grape phylloxera.
Journal of the American Society for Horticultural Science
Multiple loci in a continuously asexually reproducing genome such as vegetatively propagated grap... more Multiple loci in a continuously asexually reproducing genome such as vegetatively propagated grapevine (Vitis vinifera) can be heterozygote. The methodology to analyze heterozygous loci is manifold ranging from traditional breeding and studying segregating offspring, codominant marker analyses to whole sequence analysis. Results of heterozygosity studies on challenging loci need to be carefully confirmed to ensure accuracy and avoid misinterpretation. One of these methods is high-resolution melt (HRM) analysis in combination with sequencing and segregation analysis. We present first the adoption of HRM analyses for grapevine and its potential to confirm heterozygotic markers with low or no sequence size differences.
Fungal infections are detrimental for viticulture since they may reduce harvest yield and wine qu... more Fungal infections are detrimental for viticulture since they may reduce harvest yield and wine quality. This study aimed to characterize the effects of bunch rot and powdery mildew on wine aroma by quantification of representative aroma compounds using Stable Isotope Dilution Analysis (SIDA). For this purpose, samples affected to a high degree by each fungus were compared with a healthy sample in each case; to this aim, the respective samples were collected and processed applying identical conditions. Thereby, the effects of bunch rot were studied in three different grape varieties: White Riesling, Red Riesling and Gewürztraminer whereas the influence of powdery mildew was studied on the hybrid Gm 8622-3. Analyses revealed that both fungal diseases caused significant changes in the concentration of most target compounds. Thereby, the greatest effects were increases in the concentration of phenylacetic acid, acetic acid and γ-decalactone for both fungi and all grape varieties. Regarding other compounds, however, inconsistent effects of bunch rot were observed for the three varieties studied.
This study aimed to characterize the effects of bunch rot and powdery mildew on the primary quali... more This study aimed to characterize the effects of bunch rot and powdery mildew on the primary quality parameter of wine, the aroma. The influence of these fungal diseases was studied by comparative Aroma Extract Dilution Analyses (AEDA) and sensory tests. The effect of bunch rot was investigated on three grape varieties, namely White Riesling, Red Riesling and Gewürztraminer and that of powdery mildew on the hybrid Gm 8622-3; thereby, samples were selected that showed pronounced cases of infection to elaborate potential currently unknown effects. Both infections revealed aromatic differences induced by these fungi. The sensory changes were not associated with one specific compound only, but were due to quantitative variations of diverse substances. Bunch rot predominantly induced an increase in the intensities of peach-like/fruity, floral and liquor-like/toasty aroma notes. These effects were found to be related to variations in aroma substance composition as monitored via AEDA, mainly an increase in the FD factors of lactones and a general moderate increase of esters and alcohols. On the other hand, powdery mildew decreased the vanilla-like character of the wine while the remaining sensory attributes were rather unaffected. Correspondingly, FD factors of the main aroma constituents were either the same or only slightly modified by this disease. Moreover, bunch rot influenced the aroma profiles of the three varieties studied to a different degree. In hedonic evaluation, bunch rot-affected samples were rated as being more pleasant in comparison to their healthy controls in all three varieties while the powdery mildew-affected sample was rated as being less pleasant than its healthy control.
Botrytis cinerea and Erysiphe necator are among the most relevant fungi in viticulture. In order ... more Botrytis cinerea and Erysiphe necator are among the most relevant fungi in viticulture. In order to deepen our knowledge about their potential impact on wine quality, their effects on the aroma character of the initial stage of wine production, i.e. the must were studied. The main aroma compounds were determined by gas chromatography-olfactometry (GC-O) and ranked according to their relative intensities by means of aroma extract dilution analysis (AEDA). Clear differences between healthy and infected samples were observed. Botrytis cinerea had a positive impact on fruity and floral notes while several earthy smelling compounds were developed as result of the infection. Unlike in previous studies, however, we did not observe any clear differences in the quantities of earthy-mushroom-like smelling substances as result of the infection process with Erysiphe necator.
Cited By (since 1996): 14, Export Date: 2 March 2013, Source: Scopus, References: Bellin, D., Vel... more Cited By (since 1996): 14, Export Date: 2 March 2013, Source: Scopus, References: Bellin, D., Velasco, R., Grando, M.S., Intravarietal DNA polymorphisms in grapevine (Vitis vinifera L.) (2001) Acta Hortic, 546, pp. 343-349;
The introduction of rootstocks marks the first biologic pest control and at the same time the beg... more The introduction of rootstocks marks the first biologic pest control and at the same time the beginning of modern viticulture. Since then problems with unsuitable soil conditions may be overcome by using better adapted rootstocks. Despite this option, the number of rootstocks is still rather small and worldwide about half a dozen rootstocks are planted on approximately 60% of all sites. New soil born pests or diseases adapted to them could spread easily, repeating the phylloxera disaster. To overcome this threat more genetic rootstock diversity is needed. This task requires more new rootstocks, but also more knowledge about site adaptation of new and already existing varieties. Rootstock trials take 10 to 20 years and should be conducted on typical sites and usually private vineyards. This results in a number of restrictions regarding block size, replicates, number and kind of rootstocks being used. Despite these restrictions, such trials still provide valuable information on rootstock characteristics and site suitability. Results indicate that both already existing underutilized rootstocks, as well as recently developed hybrids with a complete phylloxera resistance mechanism, are suitable on many locations in Germany and provide the chance to enlarge genetic diversity in rootstocks and utilize site potential by better adapted rootstocks.
Monoterpenes are considered to be one of the major classes of volatile flavour components in many... more Monoterpenes are considered to be one of the major classes of volatile flavour components in many grapevine cultivars and are characteristic of fruity and floral white wines. The purpose of this study was to compare seasonal variation in monoterpene levels of different grape cultivars and characterise metabolic pathway genes leading to monoterpene production. Grape cultivars with different aromatic attributes (high to low aroma) and non-aromatic cultivars were collected at different stages during several seasons from our experimental vineyard in Geisenheim. Monoterpenes were extracted using solid phase extraction (SPE) and analysed by GC/MS. This study focused on major monoterpene alcohols linalool, geraniol and α-terpineol. In this study putative grape monoterpene synthase genes from several cultivars were sequenced and their potential for marker-assisted breeding assessed.
By parasitizing the roots of Vitis species, grape phylloxera (Daktulosphaira vitifoliae Fitch, Ph... more By parasitizing the roots of Vitis species, grape phylloxera (Daktulosphaira vitifoliae Fitch, Phylloxeridae) is one of the most devastating pests in viticulture. Grafting susceptible scions (Vitis vinifera) to tolerant Vitis rootstocks is a common practice to control grape phylloxera in wine growing regions worldwide. However, grape phylloxera populations still develop on the roots of most grafting combinations. Questions remain as to whether or not the impact of environmental factors on grape phylloxera population dynamics is related to Vitis rootstock cultivars. In the presented field study, we investigated the influence of two closely related mature Vitis berlandieri x Vitis riparia rootstock varieties on the relations between the dynamics of root feeding grape phylloxera populations, root morphology and abiotic factors. The investigation took place on a commercial vineyard in Geisenheim/Germany on Teleki 5C/V. vinifera 'Weisser Riesling' and Kober 125AA/V. vinifera '...
Australian Journal of Grape and Wine Research, 2016
Background and Aims Daktulosphaira vitifoliae Fitch (grape phylloxera, Phylloxeridae) is one of t... more Background and Aims Daktulosphaira vitifoliae Fitch (grape phylloxera, Phylloxeridae) is one of the most devastating pests in viticulture, mainly because of their root feeding activity. Up to today fundamental relations between belowground habitat and population dynamics remain unclear. In this 2-year study, we investigated the relations between grape phylloxera population and phenotypic traits of roots and feedings sites. Methods and Results We extracted root and soil samples frequently of two closely related mature rootstocks [Vitis berlandieri × V. riparia (cvs 5C and 125AA)]. We quantified and characterised larval population and crowding and assessed root gall pigmentation, root morphology and soil parameters. We identified and described three stages of seasonal population dynamics: reproduction, overwintering and declining. Further, we demonstrated a significant impact of root gall pigmentation and crowding on population dynamics. Conclusions In temperate climates, grape phylloxera is able to overwinter at high density on roots of American rootstocks. Population dynamics are highly dependent on root gall development and the ability to crowd. Significance of the Study The results of our study are considered to have a significant impact on the development of management strategies for grape phylloxera.
Journal of the American Society for Horticultural Science
Multiple loci in a continuously asexually reproducing genome such as vegetatively propagated grap... more Multiple loci in a continuously asexually reproducing genome such as vegetatively propagated grapevine (Vitis vinifera) can be heterozygote. The methodology to analyze heterozygous loci is manifold ranging from traditional breeding and studying segregating offspring, codominant marker analyses to whole sequence analysis. Results of heterozygosity studies on challenging loci need to be carefully confirmed to ensure accuracy and avoid misinterpretation. One of these methods is high-resolution melt (HRM) analysis in combination with sequencing and segregation analysis. We present first the adoption of HRM analyses for grapevine and its potential to confirm heterozygotic markers with low or no sequence size differences.
Fungal infections are detrimental for viticulture since they may reduce harvest yield and wine qu... more Fungal infections are detrimental for viticulture since they may reduce harvest yield and wine quality. This study aimed to characterize the effects of bunch rot and powdery mildew on wine aroma by quantification of representative aroma compounds using Stable Isotope Dilution Analysis (SIDA). For this purpose, samples affected to a high degree by each fungus were compared with a healthy sample in each case; to this aim, the respective samples were collected and processed applying identical conditions. Thereby, the effects of bunch rot were studied in three different grape varieties: White Riesling, Red Riesling and Gewürztraminer whereas the influence of powdery mildew was studied on the hybrid Gm 8622-3. Analyses revealed that both fungal diseases caused significant changes in the concentration of most target compounds. Thereby, the greatest effects were increases in the concentration of phenylacetic acid, acetic acid and γ-decalactone for both fungi and all grape varieties. Regarding other compounds, however, inconsistent effects of bunch rot were observed for the three varieties studied.
This study aimed to characterize the effects of bunch rot and powdery mildew on the primary quali... more This study aimed to characterize the effects of bunch rot and powdery mildew on the primary quality parameter of wine, the aroma. The influence of these fungal diseases was studied by comparative Aroma Extract Dilution Analyses (AEDA) and sensory tests. The effect of bunch rot was investigated on three grape varieties, namely White Riesling, Red Riesling and Gewürztraminer and that of powdery mildew on the hybrid Gm 8622-3; thereby, samples were selected that showed pronounced cases of infection to elaborate potential currently unknown effects. Both infections revealed aromatic differences induced by these fungi. The sensory changes were not associated with one specific compound only, but were due to quantitative variations of diverse substances. Bunch rot predominantly induced an increase in the intensities of peach-like/fruity, floral and liquor-like/toasty aroma notes. These effects were found to be related to variations in aroma substance composition as monitored via AEDA, mainly an increase in the FD factors of lactones and a general moderate increase of esters and alcohols. On the other hand, powdery mildew decreased the vanilla-like character of the wine while the remaining sensory attributes were rather unaffected. Correspondingly, FD factors of the main aroma constituents were either the same or only slightly modified by this disease. Moreover, bunch rot influenced the aroma profiles of the three varieties studied to a different degree. In hedonic evaluation, bunch rot-affected samples were rated as being more pleasant in comparison to their healthy controls in all three varieties while the powdery mildew-affected sample was rated as being less pleasant than its healthy control.
Botrytis cinerea and Erysiphe necator are among the most relevant fungi in viticulture. In order ... more Botrytis cinerea and Erysiphe necator are among the most relevant fungi in viticulture. In order to deepen our knowledge about their potential impact on wine quality, their effects on the aroma character of the initial stage of wine production, i.e. the must were studied. The main aroma compounds were determined by gas chromatography-olfactometry (GC-O) and ranked according to their relative intensities by means of aroma extract dilution analysis (AEDA). Clear differences between healthy and infected samples were observed. Botrytis cinerea had a positive impact on fruity and floral notes while several earthy smelling compounds were developed as result of the infection. Unlike in previous studies, however, we did not observe any clear differences in the quantities of earthy-mushroom-like smelling substances as result of the infection process with Erysiphe necator.
Cited By (since 1996): 14, Export Date: 2 March 2013, Source: Scopus, References: Bellin, D., Vel... more Cited By (since 1996): 14, Export Date: 2 March 2013, Source: Scopus, References: Bellin, D., Velasco, R., Grando, M.S., Intravarietal DNA polymorphisms in grapevine (Vitis vinifera L.) (2001) Acta Hortic, 546, pp. 343-349;
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