In India, post-rainy season sorghum, a cereal crop is very crucial for food and fodder security in the drought prone areas. The aim of this study was to provide an improved or better index to identify drought-tolerant genotypes. Stress susceptible index (SSI) is currently the most commonly used index by plant breeders globally to select drought-tolerant genotypes. However, SSI has certain limitations which can be addressed by new index, i.e., weighted geometric mean index (WGMI). In the present study, 42 and 25 genotypes were evaluated under three environments during the post-rainy seasons of 2015–2016 and 2016–2017, respectively, using split plot design. Genotypes were categorized as tolerant, moderately tolerant and susceptible using model WGMI. Significant and negative correlations were observed between WGMI and SSI for grain and stover yield in most of the cases. The best index to identify drought-tolerant genotypes must be highly significantly correlated with traits under stress and non-stress environments. In this context, our proposed index demonstrated higher correlation with grain and stover yield in comparison with SSI and higher coefficient of determination to identify drought-tolerant genotypes. WGMI was found to be more appropriate and reliable indicator, as it gives information regarding higher yield along with drought tolerance. In addition, it was shown to provide information on wide adaptability of genotypes under several environments. The correlation studies suggested that the traits associated with drought tolerance were early flowering, longer peduncle length and higher panicle emergence (percent).

中文翻译：

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加权几何平均指数：评估雨季后高粱（Sorghum bicolor (L.) Moench）耐旱性的模型

在印度，雨季后高粱是一种谷物作物，对于干旱易发地区的粮食和饲料安全至关重要。本研究的目的是提供一种改进的或更好的指标来识别耐旱基因型。胁迫敏感指数（SSI）是目前全球植物育种者最常用的选择耐旱基因型的指标。然而，SSI 有一定的局限性，可以通过新的指数来解决，即加权几何平均指数（WGMI）。在本研究中，分别使用裂区设计在 2015-2016 和 2016-2017 雨季后的三种环境下评估了 42 和 25 种基因型。使用模型 WGMI 将基因型分类为耐受、中度耐受和易感。在大多数情况下，在谷物和秸秆产量的 WGMI 和 SSI 之间观察到显着和负相关。鉴定耐旱基因型的最佳指标必须与胁迫和非胁迫环境下的性状高度显着相关。在这种情况下，与 SSI 相比，我们提出的指数与谷物和秸秆产量的相关性更高，并且确定耐旱基因型的决定系数更高。WGMI 被认为是更合适和可靠的指标，因为它提供了关于更高产量和耐旱性的信息。此外，它被证明可以提供有关基因型在多种环境下的广泛适应性的信息。相关性研究表明，与耐旱性相关的性状是早花、