ABSTRACT Plasmopara viticola (Berk. & M. A. Curtis) Berl & de Toni is a biotrophic oomycete responsible for downy mildew on grapevine. This study aimed to compare the development of P. viticola between a resistant interspecific hybrid of Vitis labrusca (‘Ives’, synonym ‘Bordô’), and a susceptible V. vinifera (‘Cabernet Sauvignon’) cultivars at different times after inoculation with the pathogen. The host leaf tissues were analysed at 0, 6, 12, 24, 48, 72, 96 and 120-h post-inoculation (hpi), by means of light optical microscopy and scanning electronic microscope (SEM). Light optical microscopy was used to analyse the pathogen development in the mesophyll intercellular spaces, as well as the histochemical changes occurring at host level during the infection. Structural differences were observed in stomata, and in the shape of mesophyll cells in the resistant cultivar after infection. SEM analysis showed differences in the pathogen development between both cultivars. All the stages of pathogen development were observed on the leaf surface of cv. ‘Cabernet Sauvignon’, but not in the cv. ‘Ives’. The results showed that cv. ‘Ives’ and ‘Cabernet Sauvignon’ display structural and histochemical differences to the downy mildew infection. Implications of these differences to the plant–pathogen interactions are discussed.

中文翻译：

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葡萄藤抗性（Vitis labrusca L.）和易感性（Vitis vinifera L.）葡萄品种对霜霉病感染的组织病理学研究

摘要 Plasmopara viticola (Berk. & MA Curtis) Berl & de Toni 是一种生物营养卵菌，负责葡萄藤上的霜霉病。本研究旨在比较 Vitis labrusca（'Ives'，同义词'Bordô'）和易感 V. vinifera（'Cabernet Sauvignon'）品种在接种病原。通过光学显微镜和扫描电子显微镜 (SEM) 在接种后 0、6、12、24、48、72、96 和 120 小时 (hpi) 分析寄主叶组织。光学显微镜用于分析叶肉细胞间隙中病原体的发育，以及感染过程中宿主水平发生的组织化学变化。在气孔中观察到结构差异，抗病品种侵染后呈叶肉细胞形态。SEM 分析显示两个品种之间的病原体发育存在差异。在 cv. 的叶表面观察到病原体发育的所有阶段。“赤霞珠”，但不在简历中。'艾夫斯'。结果表明，cv。'Ives' 和 'Cabernet Sauvignon' 显示出与霜霉病感染的结构和组织化学差异。讨论了这些差异对植物-病原体相互作用的影响。'Ives' 和 'Cabernet Sauvignon' 显示出与霜霉病感染的结构和组织化学差异。讨论了这些差异对植物-病原体相互作用的影响。'Ives' 和 'Cabernet Sauvignon' 显示出与霜霉病感染的结构和组织化学差异。讨论了这些差异对植物-病原体相互作用的影响。