普通豆(PhaseolusvulgarisL.)是非洲第二重要的膳食蛋白质来源和第三重要的卡路里来源,尤其是穷人。在东非,干旱是制约豆类生产的重要因素。因此,东非的育种计划一直在尝试开发普通豆类的抗旱品种。要做到这一点,育种者需要有关季节性干旱胁迫模式的信息,包括它们的发作,强度,和育种计划目标区域的持续时间,这样他们就可以在现场试验中模仿这种模式。使用农业技术转让决策支持(DSSAT)v4.7模型以及历史和未来(耦合模型相互比较项目6,CMIP6)气候数据,这项研究对埃塞俄比亚进行了分类,坦桑尼亚,根据历史和未来的季节性干旱胁迫模式,将乌干达分为不同的目标环境种群(TPE)。我们发现,在历史条件下,无压力条件通常在三个国家占主导地位(频率为50-80%)。预计埃塞俄比亚的这些情况将增加2-10%,但到2050年,坦桑尼亚(减少2-8%)和乌干达(减少17-20%)的频率则相反,这取决于共享社会经济途径(SSP)。因此,到2050年,各种强度的最终干旱胁迫(中度,严重,极端)在乌干达34%的地区普遍存在,大约四分之一的埃塞俄比亚,以及坦桑尼亚40%的豆类种植环境。在每个国家/地区确定的TPE是在国家计划中优先考虑育种活动的基础。然而,优化国际育种计划中的资源使用,以开发能够适应未来预测压力模式的基因型,我们认为,常见的豆育种计划应主要集中在识别具有严重极端干旱耐受性的基因型,与适应中度和极端极端干旱有关的共同利益。到2050年,几乎没有必要强调热应力。
Common bean (Phaseolus vulgaris L.) is the second most important source of dietary protein and the third most important source of calories in Africa, especially for the poor. In East Africa, drought is an important constraint to bean production. Therefore, breeding programs in East Africa have been trying to develop drought resistant varieties of common bean. To do this, breeders need information about seasonal drought stress patterns including their onset, intensity, and duration in the target area of the breeding program, so that they can mimic this pattern during field trials. Using the Decision Support for Agrotechnology Transfer (DSSAT) v4.7 model together with historical and future (Coupled Model Inter-comparison Project 6, CMIP6) climate data, this study categorized Ethiopia, Tanzania, and Uganda into different target population of environments (TPEs) based on historical and future seasonal drought stress patterns. We find that stress-free conditions generally dominate across the three countries under historical conditions (50-80% frequency). These conditions are projected to increase in frequency in Ethiopia by 2-10% but the converse is true for Tanzania (2-8% reduction) and Uganda (17-20% reduction) by 2050 depending on the Shared Socioeconomic Pathway (SSP). Accordingly, by 2050, terminal drought stresses of various intensities (moderate, severe, extreme) are prevalent in 34% of Uganda, around a quarter of Ethiopia, and 40% of the bean growing environments in Tanzania. The TPEs identified in each country serve as a basis for prioritizing breeding activities in national programs. However, to optimize resource use in international breeding programs to develop genotypes that are resilient to future projected stress patterns, we argue that common bean breeding programs should focus primarily on identifying genotypes with tolerance to severe terminal drought, with co-benefits in relation to adaptation to moderate and extreme terminal drought. Little to no emphasis on heat stress is warranted by 2050s.