G. J. Makatini, F. Halleen, C. Mutawila, P. Moyo, L. Mostert
Grapevine trunk disease fungi infect vines through openings, primarily pruning wounds. The main objective of this study was to understand the role of sucker wounds and wounds made by the removal of green shoots from the stems of potted grapevines as potential points of infection for grapevine trunk disease pathogens. Six wine and four table grape vineyards of different ages were sampled in different production areas in the Western Cape grape region of South Africa. Isolations were made from 161 sucker wounds, and fungal pathogens were identified using morphology and DNA sequence analysis of the internal transcribed spacers (ITS1 and ITS2) and the 5.8S ribosomal RNA gene, the translation elongation factor 1alpha or the partial β-tubulin gene. The results show that 62% of the sucker wounds were infected by trunk disease pathogens, including Diaporthe ampelina, Diplodia seriata, Phaeomoniella chlamydospora, Phaeoacremonium minimum, Eutypella microtheca, Cryptovalsa ampelina and Neofusicoccum australe. Diaporthe ampelina was the most common, followed by D. seriata and P. chlamydospora, in both the wine and table grape sucker wounds. Under glasshouse conditions, wounds made by the removal of young green shoots on one-year-old potted grapevine plants were inoculated with spore suspensions of D. ampelina, E. lata, N. parvum, P. minimum and P. chlamydospora. After four months, all the inoculated pathogens could be re-isolated. This study shows that grapevine sucker and green shoot wounds are susceptible to different grapevine trunk disease pathogens and may therefore play a role in the epidemiology of trunk diseases.
{"title":"Susceptibility of Grapevine Sucker and Green Shoot Wounds to Trunk Disease Pathogens","authors":"G. J. Makatini, F. Halleen, C. Mutawila, P. Moyo, L. Mostert","doi":"10.21548/44-1-5877","DOIUrl":"https://doi.org/10.21548/44-1-5877","url":null,"abstract":"Grapevine trunk disease fungi infect vines through openings, primarily pruning wounds. The main objective of this study was to understand the role of sucker wounds and wounds made by the removal of green shoots from the stems of potted grapevines as potential points of infection for grapevine trunk disease pathogens. Six wine and four table grape vineyards of different ages were sampled in different production areas in the Western Cape grape region of South Africa. Isolations were made from 161 sucker wounds, and fungal pathogens were identified using morphology and DNA sequence analysis of the internal transcribed spacers (ITS1 and ITS2) and the 5.8S ribosomal RNA gene, the translation elongation factor 1alpha or the partial β-tubulin gene. The results show that 62% of the sucker wounds were infected by trunk disease pathogens, including Diaporthe ampelina, Diplodia seriata, Phaeomoniella chlamydospora, Phaeoacremonium minimum, Eutypella microtheca, Cryptovalsa ampelina and Neofusicoccum australe. Diaporthe ampelina was the most common, followed by D. seriata and P. chlamydospora, in both the wine and table grape sucker wounds. Under glasshouse conditions, wounds made by the removal of young green shoots on one-year-old potted grapevine plants were inoculated with spore suspensions of D. ampelina, E. lata, N. parvum, P. minimum and P. chlamydospora. After four months, all the inoculated pathogens could be re-isolated. This study shows that grapevine sucker and green shoot wounds are susceptible to different grapevine trunk disease pathogens and may therefore play a role in the epidemiology of trunk diseases.","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41870801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wine is known as a source of bioactive compounds and is one of the alcoholic beverages with the highest phenolic content. There has been growing interest in the composition of wine due to its beneficial properties for human health. This work focuses on biologically active and sensory attributes of white wine and presents research on wine chemical profiles in relation to their geographical origin, varieties and storage. The aim of this study was to investigate the phenolic compound evolution of 35 selected white wine varieties from the Moravian region in the Czech Republic. To separate and identify individual phenolic compounds in the wines, the high-performance liquid chromatographic method was used. A spectrophotometric method was applied for the determination of total polyphenol and total flavonoid content. This research presents results for the total benzoic and cinnamic acid derivatives, flavonols, flavanols and stilbene content of Moravian white grape varieties. Differences were found in the content of these compounds, and the results show that the phenolic concentrations depend on grape variety and storage time.
{"title":"Evolution of the Polyphenolic Content of Moravian White Grape Variety Wines of Different Vintages During Storage","authors":"R. Vašková, L. Snopek, J. Mlček","doi":"10.21548/44-1-5428","DOIUrl":"https://doi.org/10.21548/44-1-5428","url":null,"abstract":"Wine is known as a source of bioactive compounds and is one of the alcoholic beverages with the highest phenolic content. There has been growing interest in the composition of wine due to its beneficial properties for human health. This work focuses on biologically active and sensory attributes of white wine and presents research on wine chemical profiles in relation to their geographical origin, varieties and storage. The aim of this study was to investigate the phenolic compound evolution of 35 selected white wine varieties from the Moravian region in the Czech Republic. To separate and identify individual phenolic compounds in the wines, the high-performance liquid chromatographic method was used. A spectrophotometric method was applied for the determination of total polyphenol and total flavonoid content. This research presents results for the total benzoic and cinnamic acid derivatives, flavonols, flavanols and stilbene content of Moravian white grape varieties. Differences were found in the content of these compounds, and the results show that the phenolic concentrations depend on grape variety and storage time.","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43958947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. J. Cornelissen, J. Aleixandré-Tudo, H. Nieuwoudt
Producer wineries are responsible for the processing of 75% of South Africa’s annual wine grape production. Characteristic to producer wineries is the processing of large volumes of wine grapes, thus incorporating enormous variability in grape quality, which include the presence of grapevine bunch rots. Grapevine bunch rots are detrimental to grape and wine quality. This review begins with the authors bringing background on the industrial situation at producer wineries. A section follows where the economic effect of rot infection on wine production is written about. Two principal reasons why rot infections are inevitably part of grape production are discussed. Challenges for producer wineries in terms of accurate rot assessment is set out. The last part of the review focusses on the quest for sustainable assessment of grapevine bunch rot infections under industrial conditions. Infrared spectroscopy (IR) could provide a sustainable option for objective assessment of rot infection on-site at producer wineries. However, even with the availability of plenty of spectroscopic methods, as well as demonstrated potential of IR spectroscopy for rapid assessment of grapevine bunch rot infections, these methods are yet to be applied routinely under industrial conditions.
{"title":"Winery on-site assessment of grapevine bunch rot: In pursuit of sustainable practices: Winery On-site Assessment of Grapevine Bunch Rot","authors":"R. J. Cornelissen, J. Aleixandré-Tudo, H. Nieuwoudt","doi":"10.21548/44-1-5701","DOIUrl":"https://doi.org/10.21548/44-1-5701","url":null,"abstract":"Producer wineries are responsible for the processing of 75% of South Africa’s annual wine grape production. Characteristic to producer wineries is the processing of large volumes of wine grapes, thus incorporating enormous variability in grape quality, which include the presence of grapevine bunch rots. Grapevine bunch rots are detrimental to grape and wine quality. This review begins with the authors bringing background on the industrial situation at producer wineries. A section follows where the economic effect of rot infection on wine production is written about. Two principal reasons why rot infections are inevitably part of grape production are discussed. Challenges for producer wineries in terms of accurate rot assessment is set out. The last part of the review focusses on the quest for sustainable assessment of grapevine bunch rot infections under industrial conditions. Infrared spectroscopy (IR) could provide a sustainable option for objective assessment of rot infection on-site at producer wineries. However, even with the availability of plenty of spectroscopic methods, as well as demonstrated potential of IR spectroscopy for rapid assessment of grapevine bunch rot infections, these methods are yet to be applied routinely under industrial conditions.","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47859211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Water is becoming an increasingly scarce resource, so agriculture competes with urban and industrial needs for water. The production of table grapes with high export potential is the objective of South African producers. Growth, production, ripening aspects and quality parameters of table grapes can potentially be manipulated by means of irrigation. Consequently, it is an important management practice to help ensure economically viable table grape production. The objective for optimum irrigation scheduling should be to combine soil and plant water status measurements to calibrate grapevine water potential against reliable soil water monitoring instruments. Considering previously reported literature, poorer vegetative growth was related to lower levels of leaf water potential (YL). Given that berry size is a crucial aspect for yield as well as quality, it was evident that low levels of water potential can restrict berry development, thereby reducing berry size. Bunch mass was lower where there were lower levels of YL, pre-dawn leaf water potential (YPD) and total diurnal water potential (YTot). Poorer yield was generally related to lower levels of YL experienced throughout the season. However, lower levels of YL in the post-veraison period did not affect grapevine yield. The juice TSS did not respond to levels of YL but juice total titratable acidity (TTA) was related to lower levels of YL. Grape colour was affected where wet soil conditions induced higher levels of YL as well as where dry soil conditions induced lower levels of YL.
{"title":"Using Grapevine Water Status Measurements for Irrigation Scheduling of Table Grapes - A Review","authors":"C. Howell, P. Myburgh","doi":"10.21548/44-1-5653","DOIUrl":"https://doi.org/10.21548/44-1-5653","url":null,"abstract":"Water is becoming an increasingly scarce resource, so agriculture competes with urban and industrial needs for water. The production of table grapes with high export potential is the objective of South African producers. Growth, production, ripening aspects and quality parameters of table grapes can potentially be manipulated by means of irrigation. Consequently, it is an important management practice to help ensure economically viable table grape production. The objective for optimum irrigation scheduling should be to combine soil and plant water status measurements to calibrate grapevine water potential against reliable soil water monitoring instruments. Considering previously reported literature, poorer vegetative growth was related to lower levels of leaf water potential (YL). Given that berry size is a crucial aspect for yield as well as quality, it was evident that low levels of water potential can restrict berry development, thereby reducing berry size. Bunch mass was lower where there were lower levels of YL, pre-dawn leaf water potential (YPD) and total diurnal water potential (YTot). Poorer yield was generally related to lower levels of YL experienced throughout the season. However, lower levels of YL in the post-veraison period did not affect grapevine yield. The juice TSS did not respond to levels of YL but juice total titratable acidity (TTA) was related to lower levels of YL. Grape colour was affected where wet soil conditions induced higher levels of YL as well as where dry soil conditions induced lower levels of YL.","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48701695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Rahmani, V. Rasoli, V. Abdossi, M. Ghanbari Jahromi
Drought stress is the most important environmental factor limiting the growth, development and yield of crop plants and horticulture. In this study, the induction of drought resistance in commercial cultivars (as scion) by the Ch1 rootstock was evaluated based on physiological and biochemical responses. Factorial experiment was performed in a completely randomised design (CRD) with three replications in the greenhouse. Plant materials consisted of five commercial grapevine cultivars (own-rooted plants of Black seedless, Flame seedless, Turkman seedless, Sultana and Shahani, and the scion of these cultivars grafted onto Ch1 rootstock). Drought stress treatment comprised stopping irrigation for 30 days from July to August, and not stopping irrigation was the control. Drought stress significantly reduced the membrane stability index (MSI) and the relative water content (RWC), and increased electrolyte leakage (EL), catalase, hydrogen peroxide, proline, ascorbic acid, guaiacol peroxidase, protein, sodium and potassium levels (P < 0.05). The EL and MSI in the Ch1 rootstock under drought stress decreased by 18.38% and 14.86% respectively. The Ch1 rootstock significantly increased the amount of proline, total protein and enzyme activity of guaiacol peroxidase and catalase in cultivars in a drought stress environment. The amount of hydrogen peroxide decreased in all cultivars grafted on Ch1 in both drought stress and non-drought stress environments, by 14.3% and 18.9% respectively. Sultana cultivar grafted on Ch1 rootstock showed the highest drought resistance. Therefore, it can be concluded that the Ch1 rootstock is recommended as a rootstock for inducing drought resistance in grapevine cultivar scions.
{"title":"Ch1 (Vitis vinifera L.) Rootstock Control of Scion Response to Water Stress in Some Commercial Grapevine Cultivars","authors":"H. Rahmani, V. Rasoli, V. Abdossi, M. Ghanbari Jahromi","doi":"10.21548/44-1-5325","DOIUrl":"https://doi.org/10.21548/44-1-5325","url":null,"abstract":"Drought stress is the most important environmental factor limiting the growth, development and yield of crop plants and horticulture. In this study, the induction of drought resistance in commercial cultivars (as scion) by the Ch1 rootstock was evaluated based on physiological and biochemical responses. Factorial experiment was performed in a completely randomised design (CRD) with three replications in the greenhouse. Plant materials consisted of five commercial grapevine cultivars (own-rooted plants of Black seedless, Flame seedless, Turkman seedless, Sultana and Shahani, and the scion of these cultivars grafted onto Ch1 rootstock). Drought stress treatment comprised stopping irrigation for 30 days from July to August, and not stopping irrigation was the control. Drought stress significantly reduced the membrane stability index (MSI) and the relative water content (RWC), and increased electrolyte leakage (EL), catalase, hydrogen peroxide, proline, ascorbic acid, guaiacol peroxidase, protein, sodium and potassium levels (P < 0.05). The EL and MSI in the Ch1 rootstock under drought stress decreased by 18.38% and 14.86% respectively. The Ch1 rootstock significantly increased the amount of proline, total protein and enzyme activity of guaiacol peroxidase and catalase in cultivars in a drought stress environment. The amount of hydrogen peroxide decreased in all cultivars grafted on Ch1 in both drought stress and non-drought stress environments, by 14.3% and 18.9% respectively. Sultana cultivar grafted on Ch1 rootstock showed the highest drought resistance. Therefore, it can be concluded that the Ch1 rootstock is recommended as a rootstock for inducing drought resistance in grapevine cultivar scions.","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48510396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Gutiérrez-Gamboa, X. Pinedo, W. Villena, M. Araya-Almán, P. Pszczółkowski
Bolivian viticulture is mostly found in the Central Valley of Tarija, which is characterised by a subtropical climate with high thermal oscillation in winter that results in low accumulation of chilling units. Such climatic conditions accentuate acrotony in vines, which affect budburst uniformity and, consequently, yield and bunch quality at harvest. The aim of this study was to evaluate the effect of different spur pruning strategies on the percentage of budburst and fertility of buds located in different nodal positions in both wine and table grape varieties growing in the Central Valley of Tarija. The results show that allocating spurs with fewer buds improved the budding of most of the distal buds studied. This was noted in both the wine and table grape cultivars, but mostly in the latter. Spur pruning leaving one bud improved the percentage of budburst and the fertility of the distal buds in Cabernet Sauvignon, Cardinal and Ribier, thereby preventing bud acrotony, compared to spur pruning leaving two buds. Spur pruning leaving two buds improved the budburst of latent buds in Cabernet Sauvignon. Therefore, to avoid acrotony patterns, viticulturists should perform pruning leaving one bud.
{"title":"Spur Pruning Leaving One Bud is an Interesting Viticultural Strategy to Control Bud Acrotony in Bolivian Vineyards","authors":"G. Gutiérrez-Gamboa, X. Pinedo, W. Villena, M. Araya-Almán, P. Pszczółkowski","doi":"10.21548/44-1-5710","DOIUrl":"https://doi.org/10.21548/44-1-5710","url":null,"abstract":"Bolivian viticulture is mostly found in the Central Valley of Tarija, which is characterised by a subtropical climate with high thermal oscillation in winter that results in low accumulation of chilling units. Such climatic conditions accentuate acrotony in vines, which affect budburst uniformity and, consequently, yield and bunch quality at harvest. The aim of this study was to evaluate the effect of different spur pruning strategies on the percentage of budburst and fertility of buds located in different nodal positions in both wine and table grape varieties growing in the Central Valley of Tarija. The results show that allocating spurs with fewer buds improved the budding of most of the distal buds studied. This was noted in both the wine and table grape cultivars, but mostly in the latter. Spur pruning leaving one bud improved the percentage of budburst and the fertility of the distal buds in Cabernet Sauvignon, Cardinal and Ribier, thereby preventing bud acrotony, compared to spur pruning leaving two buds. Spur pruning leaving two buds improved the budburst of latent buds in Cabernet Sauvignon. Therefore, to avoid acrotony patterns, viticulturists should perform pruning leaving one bud.","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47806838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Steyn, M. Karsten, A. Malan, H.-L. Wang, P. Addison
In South Africa, the family Heliozelidae in the order Lepidoptera is restricted to four known species. The grapevine leaf miner, Holocacista capensis, feeds between the epidermal layers of a grapevine leaf, predominantly along the leaf margin. A final instar larva will descend from the blotch mine/gallery to attach its cocoon casing (constructed from the epidermal layers of the mined gallery) to any object below the infested leaf. Five monophyletic clades and a polyphyletic group have been identified within the Heliozelidae, using a mitochondrially encoded gene cytochrome c oxidase I (COI) and a nuclear gene, histone 3 (H3). An exploratory study of the genetic diversity within H. capensis populations was conducted using these genes. The phylogenetic analyses of COI indicate that H. capensis that are currently being collected from South Africa fall within three clades/haplotypes, of which one is well supported and contains only one species from Gauteng, and one has three specimens from two different areas in the Western Cape province, while 80% belong to haplotype 1 (H1). The current study can be used as a starting point for future DNA-based studies aimed at gaining insight into possible patterns of diversity in H. capensis to confirm switching from native to commercial grapevine hosts. However, more samples need to be collected from different areas in South Africa.
{"title":"Phylogeny of Holocacista capensis (Lepidoptera: Heliozelidae) from Vineyards and Natural Forests in South Africa Inferred from Mitochondrial and Nuclear Genes","authors":"L. Steyn, M. Karsten, A. Malan, H.-L. Wang, P. Addison","doi":"10.21548/44-1-5945","DOIUrl":"https://doi.org/10.21548/44-1-5945","url":null,"abstract":"In South Africa, the family Heliozelidae in the order Lepidoptera is restricted to four known species. The grapevine leaf miner, Holocacista capensis, feeds between the epidermal layers of a grapevine leaf, predominantly along the leaf margin. A final instar larva will descend from the blotch mine/gallery to attach its cocoon casing (constructed from the epidermal layers of the mined gallery) to any object below the infested leaf. Five monophyletic clades and a polyphyletic group have been identified within the Heliozelidae, using a mitochondrially encoded gene cytochrome c oxidase I (COI) and a nuclear gene, histone 3 (H3). An exploratory study of the genetic diversity within H. capensis populations was conducted using these genes. The phylogenetic analyses of COI indicate that H. capensis that are currently being collected from South Africa fall within three clades/haplotypes, of which one is well supported and contains only one species from Gauteng, and one has three specimens from two different areas in the Western Cape province, while 80% belong to haplotype 1 (H1). The current study can be used as a starting point for future DNA-based studies aimed at gaining insight into possible patterns of diversity in H. capensis to confirm switching from native to commercial grapevine hosts. However, more samples need to be collected from different areas in South Africa.","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44408298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Hoogendijk, P. Myburgh, C. Howell, Arc Infruitec-Nietvoorbij
be managed to a minimum. Most of the information regarding treated municipal wastewater has been generated through laboratory studies using simulated wastewater, or in some cases actual wastewater. No studies have yet investigated the impact of irrigation with treated municipal wastewater under the conditions that prevail in South African grape growing regions
{"title":"Irrigation of Agricultural Crops with Municipal Wastewater - A Review","authors":"K. Hoogendijk, P. Myburgh, C. Howell, Arc Infruitec-Nietvoorbij","doi":"10.21548/44-1-5718","DOIUrl":"https://doi.org/10.21548/44-1-5718","url":null,"abstract":"be managed to a minimum. Most of the information regarding treated municipal wastewater has been generated through laboratory studies using simulated wastewater, or in some cases actual wastewater. No studies have yet investigated the impact of irrigation with treated municipal wastewater under the conditions that prevail in South African grape growing regions","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43609780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The exposure of grapevines to unfavourable conditions such as drought, high or low temperature and pathogenic attack increases the production of reactive oxygen species, thus inducing oxidative stress. One of the most important non-enzymatic antioxidants is ascorbic acid, which is used by plants to protect themselves against these toxic oxygen intermediates. DHA, DKG and threonate are ascorbic acid metabolites that are found during ascorbic acid catabolism. This study was done in two regions, the one in Wellington, classified as a warmer climate, and the other in Elgin, classified as a cooler climate. In each region, two Sauvignon blanc vineyard blocks were selected, with north to south and east to west row directions. Vines were monitored during the growing season to investigate the trends in the development of ascorbic acid metabolites in both regions. Canopy management practices were done at different ripening stages. Grape berries were sampled at different phenological stages according to the Eichhorn Lorenz scale: E-L 32, E-L 34, E-L 35, E-L 37 and E-L 38. Ascorbic acid derivative concentrations in the two regions varied significantly in that Elgin showed higher concentrations than Wellington at E-L 32 and E-L 38. Both the cool and warm regions had high concentrations of threonate, with no significant difference among stages of ripeness. The DHA, DKG and threonate levels were the highest at the E-L 32 phenological stage for both regions, with no significant differences among the other phenological stages, especially for DHA derivative concentrations. No significant effect on the DHA, DKG and threonate levels of the grapes was observed between row directions in each region.
{"title":"Ascorbic Acid Derivatives in the Sauvignon Blanc Cultivar (Vitis vinifera L.) During Berry Development in the Wellington and Elgin Regions","authors":"M. Dalicuba, A. Nel, F.P. van Jaarsvled","doi":"10.21548/42-2-4394","DOIUrl":"https://doi.org/10.21548/42-2-4394","url":null,"abstract":"The exposure of grapevines to unfavourable conditions such as drought, high or low temperature and pathogenic attack increases the production of reactive oxygen species, thus inducing oxidative stress. One of the most important non-enzymatic antioxidants is ascorbic acid, which is used by plants to protect themselves against these toxic oxygen intermediates. DHA, DKG and threonate are ascorbic acid metabolites that are found during ascorbic acid catabolism. This study was done in two regions, the one in Wellington, classified as a warmer climate, and the other in Elgin, classified as a cooler climate. In each region, two Sauvignon blanc vineyard blocks were selected, with north to south and east to west row directions. Vines were monitored during the growing season to investigate the trends in the development of ascorbic acid metabolites in both regions. Canopy management practices were done at different ripening stages. Grape berries were sampled at different phenological stages according to the Eichhorn Lorenz scale: E-L 32, E-L 34, E-L 35, E-L 37 and E-L 38. Ascorbic acid derivative concentrations in the two regions varied significantly in that Elgin showed higher concentrations than Wellington at E-L 32 and E-L 38. Both the cool and warm regions had high concentrations of threonate, with no significant difference among stages of ripeness. The DHA, DKG and threonate levels were the highest at the E-L 32 phenological stage for both regions, with no significant differences among the other phenological stages, especially for DHA derivative concentrations. No significant effect on the DHA, DKG and threonate levels of the grapes was observed between row directions in each region.","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41683741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sensory Evaluation of Pinked Sauvignon Blanc Wines","authors":"A. Nel, W. D. Du Toit, F.P. van Jaarsvled","doi":"10.21548/42-2-4316","DOIUrl":"https://doi.org/10.21548/42-2-4316","url":null,"abstract":"","PeriodicalId":21894,"journal":{"name":"South African Journal of Enology and Viticulture","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43744656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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