Plant Science Division, College of Life Science, University of Dundee at JHI, Invergowrie, Dundee, Scotland, UK.
Plant Biol (Stuttg). 2013 Jan;15 Suppl 1:18-27. doi: 10.1111/j.1438-8677.2012.00590.x. Epub 2012 Apr 18.
Winter chilling is critical for flowering and fruiting of many temperate fruits, with evidence that blackcurrant (Ribes nigrum L.) cropping has been adversely affected by warm winters. Accurate models of chill accumulation in blackcurrant are required so that breeding strategies can be formulated for the generation of new cultivars with resilience to future climates. Existing models for chill accumulation have largely been derived from statistical correlation; here we report the derivation of improved models for blackcurrant using controlled environment treatments. Hardwood cuttings from a diverse set of cultivars were exposed to constant or varying chilling temperatures and the effects on bud break after transfer to a warm, permissive environment evaluated. The impact of different combinations of temperature and chilling periods were described in terms of their overall 'Effectiveness' (E). Clear genotypic differences were found, with excessive chilling often inhibiting bud break. There was a significant interaction between observed chilling response and the period of low temperature exposure. A number of chilling models to explain observed interactions between chilling temperature and time of exposure on bud break were compared; the most effective involved an optimal response to increasing chill accumulation. The effects of varying temperatures during chilling on bud break were complex, with warm temperature breaks substantially inhibiting bud development and cooler temperature breaks tending to enhance bud burst. The relevance of these models to generic studies of endodormancy is discussed, together with their potential application to the development of phenotyping screens for future breeding using diverse blackcurrant germplasm.
冬季低温是许多温带水果开花结果的关键因素，有证据表明，温暖的冬季会对黑穗醋栗（Ribes nigrum L.）的结果产生不利影响。需要准确的黑穗醋栗低温积累模型，以便制定新的育种策略，培育出对未来气候具有适应能力的品种。现有的低温积累模型主要是通过统计相关性得出的；在这里，我们报告了使用受控环境处理方法得出的改进的黑穗醋栗模型。从各种品种中采集的硬木插条暴露在恒定或变化的低温环境中，然后评估将其转移到温暖、允许的环境中后芽的萌发情况。不同温度和低温期组合的影响是用它们的整体“有效性”（E）来描述的。发现了明显的基因型差异，过多的低温往往会抑制芽的萌发。观察到的低温反应与低温暴露时间之间存在显著的相互作用。比较了几种解释低温对芽休眠期的影响的低温模型；最有效的模型涉及到对增加的低温积累的最佳反应。低温期内温度变化对芽休眠的影响很复杂，温暖的温度会严重抑制芽的发育，而较冷的温度则会促进芽的爆发。讨论了这些模型对终末休眠的一般性研究的相关性，以及它们在利用不同的黑穗醋栗种质资源进行未来育种的表型筛选开发中的潜在应用。
