INRA Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux. Place Viala, F-34060 Montpellier Cedex 1, France.
J Exp Bot. 2012 Jan;63(1):25-31. doi: 10.1093/jxb/err269. Epub 2011 Sep 30.
Most traits associated with drought tolerance have a dual effect, positive in very severe scenarios and negative in milder scenarios, or the opposite trend. Their effects also depend on other climatic conditions such as evaporative demand or light, and on management practices. This is the case for processes associated with cell protection and with avoidance, but also for the maintenance of growth or photosynthesis, high water use efficiency, large root systems or reduced abortion rate under water deficit. Therefore, spectacular results obtained in one drought scenario may have a limited interest for improving food security in other geographical areas with water scarcity. The most relevant questions on drought tolerance are probably, 'Does a given allele confer a positive effect on yield in an appreciable proportion of years/scenarios in a given area or target population of environment (TPE)?'; 'In a given site or TPE, what is the trade-off between risk avoidance and maintained performance?'; and 'Will a given allele or trait have an increasingly positive effect with climate change?' Considerable progress has already occurred in drought tolerance. Nevertheless, explicitly associating traits for tolerance to drought scenarios may have profound consequences on the genetic strategies, with a necessary involvement of modelling.
大多数与耐旱性相关的特征具有双重作用，在非常严重的情况下是积极的，在较温和的情况下则是消极的，或者相反。它们的影响还取决于其他气候条件，如蒸发需求或光照，以及管理实践。与细胞保护和避免相关的过程就是如此，但也包括维持生长或光合作用、高水分利用效率、较大的根系或在水分亏缺下减少流产率。因此，在一种干旱情景下获得的显著结果可能对改善其他水资源短缺地区的粮食安全没有什么实际意义。关于耐旱性，最相关的问题可能是，“给定的等位基因在给定地区或目标环境群体（TPE）的相当一部分年份/情景中对产量有积极影响吗？”“在给定的地点或 TPE 中，风险回避和保持性能之间的权衡是什么？”“给定的等位基因或特征是否会随着气候变化而产生越来越积极的影响？”耐旱性方面已经取得了相当大的进展。然而，将耐旱性特征明确地与干旱情景联系起来，可能会对遗传策略产生深远的影响，这需要模型的参与。
