PDF(Pubmed)
Abstract：
Plants exhibit an array of drought responses and adaptations, where the trade-off between water loss and CO2 uptake for growth is mediated by regulation of stomatal aperture in response to soil water content (SWC), among other factors. For crop yield stability, the question is how drought timing and response patterns relate to post-drought growth resilience and vigor. We earlier identified, in a few reference varieties of barley that differed by the SWC at which transpiration was curtailed, two divergent water use strategies: water-saving (\"isohydric\") and water-spending (\"anisohydric\"). We proposed that an isohydric strategy may reduce risk from spring droughts in climates where the probability of precipitation increases during the growing season, whereas the anisohydric is consistent with environments having terminal droughts, or with those where dry periods are short and not seasonally progressive. Here, we have examined drought response physiology in an 81-line barley (Hordeum vulgare L.) diversity set that spans 20th century European breeding and identified several lines with a third, dynamic strategy. We found a strong positive correlation between vigor and transpiration, the dynamic group being highest for both. However, these lines curtailed daily transpiration at a higher SWC than the isohydric group. While the dynamic lines, particularly cv Hydrogen and Baronesse, were not the most resilient in terms of restoring initial growth rates, their strong initial vigor and high return to initial transpiration rates meant that their growth nevertheless surpassed more resilient lines during recovery from drought. The results will be of use for defining barley physiological ideotypes suited to future climate scenarios.
摘要：
植物表现出一系列的干旱反应和适应，其中水分损失和CO2吸收之间的权衡是通过调节气孔孔径来调节土壤含水量（SWC），在其他因素中。为了作物产量的稳定性，问题是干旱时间和响应模式如何与干旱后的增长韧性和活力相关。我们之前确定，在一些大麦参考品种中，由于蒸腾作用减少的SWC而有所不同，两种不同的用水策略:节水(“等量”)和用水(“等量”)。我们提出，在生长季节降水概率增加的气候中，等相策略可以降低春季干旱的风险。而阴离子与有最终干旱的环境是一致的，或者那些干旱期短而不是季节性的人。这里,我们已经检查了81品系大麦（HordeumvulgareL.）多样性集的干旱响应生理学，该多样性集跨越20世纪的欧洲育种，并确定了几个品系，动态战略。我们发现活力和蒸腾作用之间有很强的正相关关系，两者的动态组都是最高的。然而,这些品系在比等氢基团更高的SWC下减少了每日蒸腾作用。虽然动态线条，特别是cv氢和Baronesse，在恢复初始增长率方面并不是最有弹性的，它们强大的初始活力和对初始蒸腾速率的高回报意味着它们的生长在干旱恢复期间仍然超过了更有弹性的线。结果将用于定义适合未来气候情景的大麦生理理想型。
