155 research outputs found

    Protection of Grapevine Pruning Wounds against Eutypa lata by Biological and Chemical Methods

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    Eutypa dieback, caused by the fungus Eutypa lata, is a serious disease of grapevines that infects mainly through pruningwounds. The aim of this study was to evaluate the in vitro efficacy of fungicides from various chemical groups againstE. lata, as well as the in vivo efficacy of the most effective fungicides and selected bacterial and fungal antagonists ofE. lata, in grapevine pruning wound protection trials. In vitro studies revealed that flusilazole, tebuconazole, benomyl,fenarimol and myclobutanil were the most effective fungicides to inhibit mycelial growth of E. lata. Two field trialswere conducted, one subjected to artificial inoculation and the second to natural infection only. In the first, benomyl,flusilazole and commercially available Trichoderma harzianum-containing products and an experimental Bacillussubtilis strain were applied to fresh pruning wounds. Two Cabernet Sauvignon vineyards were pruned in August2001 and 2002 and immediately treated and inoculated with a spore suspension of E. lata one day later. Isolationswere made from the treated pruning wounds after 12 months to assess the effectiveness of the treatments. Thefungicides benomyl and flusilazole were the most effective treatments, although the Trichoderma treatments T77 andTrichoseal spray caused a significant reduction in E. lata infection. In a second trial, pruning wounds of CabernetSauvignon, Sauvignon blanc, Red Globe and Bonheur were treated with the Trichoderma products Vinevax (=Trichoseal spray) and Eco77 (= T77) in August 2005 and 2006, subjected to natural infection only and evaluatedafter seven months. Vinevax and Eco77 not only reduced E. lata, but they also reduced the incidence of othergrapevine trunk disease pathogens

    Susceptibility of Grapevine Sucker and Green Shoot Wounds to Trunk Disease Pathogens

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    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 differentproduction 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

    An integrated strategy for the proactive management of grapevine trunk disease pathogen infections in grapevine nurseries

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    CITATION: Halleen, F. & Fourie, P. H. 2016. An integrated strategy for the proactive management of grapevine trunk disease pathogen infections in grapevine nurseries. South African Journal of Enology & Viticulture, 37(2):104-114, doi:10.21548/37-2-825.The original publication is available at http://www.journals.ac.za/index.php/sajevThe aim of this study was to compare 11 treatment regimes (TR) in grapevine nurseries in order to eradicate trunk pathogens. Grapevine propagation material was subjected to treatments before cold storage, before and after grafting, before planting and after uprooting. Isolations were made from roots, rootstocks and graft unions of uprooted vines. None of the treatments consistently affected the number of certifiable vines produced. TR 1 (benomyl), TR 3 (Sporekill) and TR 4 (Trichoflow) increased root mass. Phaeomoniella chlamydospora was the most frequently isolated pathogen from all plant parts. In general, TR 2, 7, 9 and 11 caused the lowest occurrence of Phaeomoniella. TR 9 consistently reduced the incidence of Phaeoacremonium. Pleurostomophora richardsiae occurred most frequently in graft unions, but treatments were too inconsistent to draw meaningful conclusions. TR 7 (hot water treatment (HWT) of uprooted grapevines) consistently reduced incidences of black foot disease (BFD) pathogens. The highest incidence of Botryosphaeriaceae occurred in graft unions, but all treatments significantly reduced infections. The colonisation of rootstocks and graft unions by Trichoderma was significantly better with TR 4 (Trichoflow). The other Trichoderma treatments (TR 9, 10 and 11) differed from the control treatment only in the graft unions. This is a first report of an integrated strategy covering all the phases of the propagation process, from the moment the nursery receives the propagation material until the dormant vines are removed. TR 9 is recommended for use in nurseries, although HWT of dormant vines is recommended to eradicate BFD pathogens. Benomyl can be replaced by carbendazim when benomyl is no longer available.http://www.journals.ac.za/index.php/sajev/article/view/825Publisher's versio

    Evidências morfológicas da ocorrência de Phaeomoniella chlamydospora em videiras no Estado do Rio Grande do Sul.

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    Em virtude de até o momento não ter sido relatada a ocorrência do fungo P. chlamydospora no Estado do Rio Grande do Sul, o objetivo do trabalho foi o de verificar a ocorrência do mesmo em videiras do Estado do Rio Grande do Sul, o que possibilita a geração de informações para futuras estratégias e ações de controle.bitstream/item/84833/1/Comunicado-Tecnico-134.pd

    Advances in propagation of grapevine in the world.

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    Grapevine production by classical grafting methods and in commercial scale emerged over 130 years. This system remained handmade until the mid-1950s, when emerged the first international certification programs aimed at obtaining mother lants with high viral sanity. The necessity to increase the scale of production on industrial model and plant material production based on minimum morphological standards appeared at the end of the 1960s. Along the 1970s, research unlocked knowledge on emi-automated grafting, process hygiene, use of plant growth regulators and understanding of physiological events of rootstock-scion compatibility, callus formation and rooting. So, until the mid-2000s, certification schemes and propagation processes advanced little in technical standard. However, grapevine growing areas were expanded and demands for plant material increased, and new diseases emerged from contaminated nurseries. These new diseases (new viral complexes, phytoplasmas, bacteria and grapevine trunk diseases) were discovered by high-sensitivity diagnostic methods. Today, there is a new discussion on the nursery segment worldwide. The propagation techniques have been reviewed from the perspective of reducing the incidence of new diseases and minimum physiological damage of nursery plants during the production stages. Therefore, technological innovations regarding equipment, practices and production inputs have been incorporated in new certification schemes. However, despite these dvantages, these schemes have become more complex and multidisciplinary than previous ones, bringing difficulties in adaptation of nurserymen. Index-terms: Vitis grafting, nursery, certification, grapevine cuttings. Propagação de videiras a partir dos métodos clássicos de enxertia e em escala comercial teve origem há mais de 130 anos. Este sistema permaneceu artesanal até meados da década de 1950, quando se iniciaram os primeiros programas internacionais de certificação com foco na obtenção de plantas básicas com elevada sanidade para vírus. No fim da década de 1960, surgiu a necessidade de aumentar a escala para produção em um modelo industrial em que a muda apresentasse um padrão morfológico mínimo. Ao longo da década de 1970, aprofundaram-se as pesquisas relacionadas à automatização da prática de enxertia, à higienização do processo, ao uso de reguladores de crescimento e ao entendimento dos eventos fisiológicos da compatibilidade entre enxerto e porta-enxerto, formação de calos e enraizamentos. Assim, até meados dos anos 2000, os esquemas de certificação e o processo de propagação pouco evoluíram em termos técnicos. Porém, a medida que a área vitícola foi expandindo e a demanda por mudas aumentando, verificou-se que novas doenças se alastravam em escala global a partir de viveiros contaminados. Estas novas doenças (complexos virais, fitoplasmas, bactérias e fungos causadores de podridões vasculares) foram sendo descobertas à medida que os métodos de diagnose avançaram em sensibilidade de detecção. Hoje, surge nova discussão no segmento viveirista mundial fundamentada no fato de que o processo de propagação está sendo revisto sob o foco da redução de incidência das novas pragas e mínimo dano à muda ao longo das etapas da produção. Surgem, assim, inovações tecnológicas, tanto em equipamentos quanto em práticas e insumos, sendo incorporadas aos novos modelos de certificação. Mas, se por um lado, estes esquemas tornam-se cada vez mais multidisciplinares, por outro, a complexidade gerada pode trazer dificuldades para a adesão pelos viveiristas. Termos para indexação: Vitis enxertia, viveiro, certificação, mudas de videira

    Cross pathogenicity of Neofusicoccum australe and Neofusicoccum stellenboschiana on grapevine and selected fruit and ornamental trees

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    [EN] Neofusicoccum australe is one of the most important Botryosphaeriaceae pathogens occurring on fruit and vine crops. This fungus was recently taxonomically reassessed, identifying N. stellenboschiana as a separate species. Previous pathogenicity studies used N. stellenboschiana and N. australe isolates as N. australe, so assessment of the pathogenicity of these two species on grapevine and other hosts was required. A pathogenicity trial was conducted on detached shoots of grapevine, plum, apple, olive and Peruvian pepper tree. Shoots were individually inoculated with 11 N. australe and eight N. stellenboschiana isolates originally isolated from grapevine, plum, apple, olive, Peruvian pepper and fig. Both species formed lesions on all five hosts and were reisolated 5 weeks post-inoculation. In general, the largest lesions were formed on plum and smallest on Peruvian pepper. Isolate host origin did not influence ability to cause lesions on other hosts. Isolates of N. australe and N. stellenboschiana differed in virulence on the various hosts, ranging from those that caused the largest lesions, a group causing intermediate lesions, and another causing lesions similar to uninoculated controls. The study demonstrates that N. australe and N. stellenboschiana isolates originating from various fruit hosts can infect alternative hosts including grapevine and other major fruit crops.This research developed from a mobility sojourn funded by the Erasmus Mundus Joint Master Degrees Programme of the European Commission under the PLANT HEALTH Project. The authors also acknowledge financial support from ARC Infruitec-Nietvoorbij and the National Research Foundation of South Africa (NRF UID88771). Technical Assistance was provided by Carine Vermeulen, Danie Marais, Julia Marais, Muriel Knipe, Lydia Maart, Christopher Paulse, Bongiwe Sokwaliwa, Nadeen van Kervel, and Levocia Williams (Plant Protection Division, ARC Infruitec-Nietvoorbij).Mojeremane, K.; Lebenya, P.; Du Plessis, IL.; Van Der Rijst, M.; Mostert, L.; Armengol Fortí, J.; Halleen, F. (2020). Cross pathogenicity of Neofusicoccum australe and Neofusicoccum stellenboschiana on grapevine and selected fruit and ornamental trees. PHYTOPATHOLOGIA MEDITERRANEA. 59(3):581-593. https://doi.org/10.14601/Phyto-11609S58159359

    DNA phylogeny, morphology and pathogenicity of Botryosphaeria species on grapevines

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    Several species of Botr yosphaeria are known to occur on grapevines, causing a wide range of disorders including bud mortality, dieback, brown wood streaking and bunch rot. In this study the 11 Botryosphaeria spp. associated with grapevines growing in various parts of the world, but primarily in South Africa, are distinguished based on morphology, DNA sequences (ITS-1, 5.8S, ITS-2 and EF1-) and pathological data. Botryosphaeria australis, B. lutea, B. obtusa, B. parva, B. rhodina and a Diplodia sp. are confirmed from grapevines in South Africa, while Diplodia porosum, Fusicoccum viticlavatum and F. vitifusiforme are described as new. Although isolates of B. dothidea and B. stevensii are confirmed from grapevines in Portugal, neither of these species occurred in South Africa, nor were any isolates of B. ribis confirmed from grapevines. All grapevine isolates from Portugal, formerly presumed to be B. ribis, are identified as B. parva based on their EF1- equence data. From artificial inoculations on grapevine shoots, we conclude that B. australis, B. parva, B. ribis and B. stevensii are more virulent than the other species studied. The Diplodia sp. collected from grapevine canes is morphologically similar but phylogenetically distinct from D. sarmentorum. Diplodia sarmentorum is confirmed as anamorph of Otthia spiraeae, the type species of the genus Otthia (Botryosphaeriaceae). A culture identified as O. spiraeae clustered within Botryosphaeria and thus is regarded as probable synonym. These findings confirm earlier suggestions that the generic concept of Botryosphaeria should be expanded to include genera with septate ascospores and Diplodia anamorphs

    Increased tartrate-resistant acid phosphatase (TRAP) expression in malignant breast, ovarian and melanoma tissue: an investigational study

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    BACKGROUND: Tartrate-resistant acid phosphatase (TRAP) is a metalloprotein enzyme that belongs to the acid phosphatases and is known to be expressed by osteoclasts. It has already been investigated as a marker of bone metastases in cancer patients. In this study, which examined the value of serum TRAP concentrations as a marker of bone disease in breast cancer patients, we observed high concentrations of TRAP even in patients without bone metastases. To elucidate this phenomenon, we examined the expression of TRAP in breast cancer cells and the cells of several other malignancies. METHODS: TRAP concentrations in the serum of tumor patients were determined by ELISA. The expression of TRAP in breast, ovarian, and cervical cancer and malignant melanoma was analyzed by immunohistochemistry. RT-PCR and immunocytology were used to evaluate TRAP expression in cultured tumor cells. RESULTS: A marked increase in serum TRAP concentrations was observed in patients with breast and ovarian cancer, regardless of the presence or absence of bone disease. TRAP expression was found in breast and ovarian cancers and malignant melanoma, while cervical cancer showed only minimal expression of TRAP. Expression of TRAP was absent in benign tissue or was much less marked than in the corresponding malignant tissue. TRAP expression was also demonstrated in cultured primary cancer cells and in commercially available cell lines. CONCLUSION: Overexpression of TRAP was detected in the cells of various different tumors. TRAP might be useful as a marker of progression of malignant disease. It could also be a potential target for future cancer therapies

    Genera of Phytopathogenic Fungi: GOPHY 4

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    This paper is the fourth contribution in the Genera of Phytopathogenic Fungi (GOPHY) series. The series provides morphological descriptions and information about the pathology, distribution, hosts and disease symptoms, as well as DNA barcodes for the taxa covered. Moreover, 12 whole-genome sequences for the type or new species in the treated genera are provided. The fourth paper in the GOPHY series covers 19 genera of phytopathogenic fungi and their relatives, including Ascochyta, Cadophora, Celoporthe, Cercospora, Coleophoma, Cytospora, Dendrostoma, Didymella, Endothia, Heterophaeomoniella, Leptosphaerulina, Melampsora, Nigrospora, Pezicula, Phaeomoniella, Pseudocercospora, Pteridopassalora, Zymoseptoria, and one genus of oomycetes, Phytophthora. This study includes two new genera, 30 new species, five new combinations, and 43 typifications of older names.The study of Ascochyta, Didymella and Leptosphaerulina were supported by the National Natural Science Foundation of China (31750001) and the National Science and Technology Fundamental Resources Investigation Program of China (MOST: 2021FY100900). The study of the genus Phytophthora was supported by the Project Phytophthora Research Centre Reg. No. CZ.02.1.01/0.0/0.0/15_003/000 0453 cofinanced by the European Regional Development Fund. ShuaiFei Chen acknowledges the National Key R&D Program of China (ChinaSouth Africa Forestry Joint Research Centre Project; 2018YFE0120900) for financial support. Mounes Bakhshi and Rasoul Zare gratefully acknowledge the Iran National Science Foundation (INSF), and Research Deputy of the Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), for financial support. The study of the genera Pseudocercospora and Pteridopassalora were partially supported by JSPS KAKENHI Grant Numbers JP20K06146 to Chiharu Nakashima
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