Sorghum [Sorghum bicolor (L.) Moench], a crucial staple crop in South Asia and sub-Saharan Africa, faces challenges amid increasing climate variability. Post-rainy sorghum serves as a dominant food and fodder crop in India. Aligned with International Crops Research Institute for the Semi-Arid Tropics's post-rainy sorghum product profile, this research extensively characterizes sorghum lines, emphasizing the traits vital for post-rainy drought adaptation in hybrid parents. We examined genotypic differences and trait correlations in 25 sorghum hybrid parents and varieties (B line for seed parent, R line for restorer, and check for varieties) through atmospheric and soil drought experiments. Results from atmospheric drought experiments revealed significant variation in transpiration rate (TR) under high vapor pressure deficit (VPD), with certain lines showing limited TR (BTX623 and ICSR 21002), while others exhibited high TR. In soil drought experiments, transpiration decline occurred at fractions of transpirable soil water ranging between 0.38 (ICSR 174) and 0.65 (40162 and ICSR 21005). R lines consistently displayed superior plant growth, water use, and biomass compared to B lines. Transpiration efficiency (TE) and total biomass showed positive correlations (r² = 0.69) in well-watered and (r² = 0.45) in water-stressed conditions. Most R lines displayed higher biomass and TE. Genotypes exhibiting enhanced vigor and limited TR in high VPD conditions and high TE hold potential for enhancing drought adaptation in post-rainy sorghum. Notably, genotypes with higher biomass, lower TR, and increased TE within both R and B line groups represent valuable genetic resources for enhancing sorghum crops, post-rainy sorghum adaptation to water deficit.

中文翻译：

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探索高粱育种系的基因型多样性以提高节水性状，以增强雨季后的干旱适应能力


高粱 [Sorghum bicolor (L.) Moench] 是南亚和撒哈拉以南非洲地区的重要主粮作物，在气候变化加剧的情况下面临着挑战。雨后高粱是印度的主要粮食和饲料作物。这项研究与国际半干旱热带作物研究所的雨后高粱产品概况相一致，广泛描述了高粱品系的特征，强调了杂交亲本对雨后干旱适应至关重要的性状。我们通过大气和土壤干旱实验研究了 25 个高粱杂交亲本和品种（B 系为种子亲本，R 系为恢复系，并检查品种）的基因型差异和性状相关性。大气干旱实验的结果显示，在高蒸气压赤字 (VPD) 下，蒸腾速率 (TR) 存在显着变化，某些品系显示出有限的 TR（BTX623 和 ICSR 21002），而其他品系则表现出较高的 TR。在土壤干旱实验中，蒸腾作用下降发生在可蒸腾土壤水分数范围在 0.38 (ICSR 174) 和 0.65 (40162 和 ICSR 21005) 之间。与 B 系相比，R 系始终表现出优异的植物生长、水分利用和生物量。蒸腾效率（TE）和总生物量在水分充足的条件下呈正相关（r ² = 0.69），在缺水的条件下呈正相关（r ² = 0.45）。大多数 R 系表现出较高的生物量和 TE。在高 VPD 条件和高 TE 条件下表现出增强活力和有限 TR 的基因型具有增强雨后高粱干旱适应的潜力。值得注意的是，R 和 B 品系组中具有较高生物量、较低 TR 和增加 TE 的基因型代表了增强高粱作物、雨后高粱适应缺水的宝贵遗传资源。