Breeding for drought tolerance using novel genetic resources possessing relevant agronomic and adaptive traits is a key to enhance productivity and food security in wheat growing areas. Herein, the main objectives were (i) to use a combination scoring index (multiple scoring index, (MSI)) for selection of durum wheat genotypes under different drought stress intensities (SIs) (ii) to examine repeatability of the scoring index through bootstrap re-sample method, and (iii) to study the relationship of MSI with some drought-adaptive traits. Sixteen durum wheat genotypes were grown under rainfed and irrigated conditions during three cropping seasons (2012–2015), resulting in different drought SIs, that is, mild (SI < 0.3), moderate (0.3 < SI < 0.6), and severe (SI > 0.6). The average grain yields among test environments varied between 708 and 3631 kg ha−1. The validation of the methodology of scoring index was confirmed by the correlation coefficients between score indices and their original values across different drought SIs. According to MSI, the genotypes G16, G1, and G3 had the best combination of high productivity and high resilience to mild, moderate, and severe drought stress conditions, respectively. These results indicated that the ranking of genotypes varied among different drought SIs, which support the high potential of durum wheat for adaptation to different drought stress conditions. Based on the bootstrap samples, non-repeatable correlations were observed between the estimates of MSI from different levels of stress. The significant correlation between MSI with grain yield and 1000-kernel weight (TKW) under severe drought condition provides evidence that MSI ultimately be considered as a tool for effective selection of drought-tolerant genotypes. The MSI selected genotypes based on high productivity and resilience, to each level of drought SI, and favorable adaptive traits useful for breeding.

中文翻译：

---

使用组合评分指数提高干旱胁迫下硬粒小麦的生产力

利用具有相关农艺和适应性特征的新型遗传资源培育耐旱性是提高小麦种植区生产力和粮食安全的关键。在此，主要目标是（i）使用组合评分指数（多重评分指数，（MSI））选择不同干旱胁迫强度（SI）下的硬粒小麦基因型（ii）通过引导程序检查评分指数的可重复性重采样方法，以及（iii）研究MSI与一些干旱适应性状的关系。在三个种植季节（2012-2015）期间，在雨养和灌溉条件下种植了 16 个硬粒小麦基因型，导致不同的干旱 SI，即轻度（SI < 0.3）、中度（0.3 < SI < 0.6）和重度（SI > 0.6)。-1. 评分指数方法的有效性通过评分指数与其原始值在不同干旱 SI 之间的相关系数得到证实。根据 MSI，基因型 G16、G1 和 G3 分别具有对轻度、中度和重度干旱胁迫条件的高生产力和高复原力的最佳组合。这些结果表明，不同干旱 SI 的基因型排序不同，这支持了硬粒小麦适应不同干旱胁迫条件的高潜力。基于 bootstrap 样本，在不同压力水平的 MSI 估计值之间观察到不可重复的相关性。在严重干旱条件下，MSI与谷物产量和千粒重（TKW）之间的显着相关性提供了证据，表明MSI最终被认为是有效选择耐旱基因型的工具。MSI 选择的基因型基于高生产力和复原力、每个干旱 SI 水平以及对育种有用的有利适应性特征。