Bud dormancy and cold hardiness are critical adaptations for surviving winter cold stress for temperate perennial plant species. In grapevine, acquisition of cold hardiness requires dormancy induction in the early winter and careful maintenance of dormancy state throughout winter. With sufficient exposure to low, non-freezing temperatures (chilling requirement), grapevine buds transition between early (endodormant) and late winter (ecodormant) states. The objective of this study was to uncover the relationship between fulfilment of the chilling requirement and the effects of various temperatures on loss of cold hardiness (deacclimation). The relationship between chilling requirement and temperature as it affects the rate of deacclimation (k deacc) was examined for dormant cuttings of Vitis vinifera, V. aestivalis, V. amurensis and V. riparia. The effect of temperature on k deacc was exponential at low and logarithmic at high temperatures. Deacclimation rates also increased in magnitude as chilling accumulated demonstrating a change in deacclimation potential (Ψdeacc), following a logarithmic response. The combination of Ψdeacc and k deacc indicates genotype-specific thermal efficiency for deacclimation and growth in Vitis that may be overlooked by simple growing degree-day computations. The Ψdeacc and k deacc parameters are genotype-specific and will greatly increase the refinement of models predicting effects of climate change on phenology. Deacclimation rates represent a quantitative determinant of dormancy transition and budbreak in grapevine and will assist researchers in selecting germplasm for differences in chilling requirement and thermal efficiency.

中文翻译：

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脱驯动力学作为定量表型，用于描述葡萄树种的休眠转变和芽的热效率。

芽休眠和抗寒性是温带多年生植物在冬季寒冷胁迫下生存的关键适应条件。在葡萄中，获得抗寒性需要在初冬诱导休眠，并在整个冬季仔细保持休眠状态。充分暴露于较低的非冻结温度（需要冷藏）后，葡萄芽会在早期（内香）状态和冬季后期（ecodormant）状态之间过渡。这项研究的目的是揭示满足冷藏要求与各种温度对抗寒性（去驯化）的影响之间的关系。研究了低温需求与温度之间的关系，因为它影响去适应率（k deacc），用于葡萄，葡萄，葡萄，葡萄和河岸豆的休眠插条。温度对k deacc的影响在低温时呈指数变化，而在高温时呈对数变化。随着对数响应，冷积累的增加表明了去驯化潜能的变化（Ψdeacc），去驯化的幅度也有所增加。Ψdeacc和k deacc的组合表示葡萄的去适应和生长的基因型特异性热效率，可以通过简单的生长度日计算来忽略。Ψdeacc和k deacc参数是特定于基因型的，将大大提高预测气候变化对物候的影响的模型的准确性。驯化速率代表葡萄休眠休眠和芽芽的定量决定因素，将帮助研究人员选择种质，以适应冷藏需求和热效率的差异。