Sorghum [Sorghum bicolor (L.) Moench] is highly sensitive to chilling temperatures (<15°C soil temperatures) during germination and early seedling establishment. Hence, the main objectives of this research were to (a) validate the potential level of chilling tolerance in selected sorghum genotypes, (b) determine effective concentrations of selected safeners for improving chilling tolerance and (c) determine if safener combinations further enhance chilling tolerance compared to individual safener treatments. Four experiments were conducted with five sorghum genotypes, four safeners (oxabetrinil, fluxofenim, naphthalic anhydride and benoxacor), nine safener concentrations (0–25 μM) and two temperatures. The chilling-tolerant genotypes recorded higher germination percentage (98% vs. 63%) and root (3.0 vs. 0.8 cm) and shoot lengths (0.7 vs. 0.1 cm) compared to sensitive genotypes under continuous 15℃. Each of the four safeners applied at the highest concentrations tested (20 and 25 μM) significantly enhanced seed germination and seedling growth at 15℃. The combination of four safeners was more effective in reducing chilling stress-induced injury compared to individual, two- or three-way combinations. Enhanced chilling tolerance may be extended to other cereal crops after optimizing the genetic background and effects of agro-climatic conditions on safener chemistry, concentration, and proper combination of seed-applied safeners.

中文翻译：

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安全剂可提高高粱的早期冷胁迫耐受性

高粱 [ Sorghum bicolor(L.) Moench] 对发芽和早期幼苗建立期间的寒冷温度（<15°C 土壤温度）高度敏感。因此，本研究的主要目标是 (a) 验证选定高粱基因型的耐冷性潜在水平，(b) 确定用于提高耐寒性的选定安全剂的有效浓度，以及 (c) 确定安全剂组合是否进一步增强耐寒性与单独的安全剂治疗相比。使用五种高粱基因型、四种安全剂（oxabetrinil、fluxofenim、萘酐和苯诺沙克）、九种安全剂浓度（0-25 μM）和两种温度进行了四项实验。耐寒基因型记录了更高的发芽率（98% 对 63%）和根（3.0 对 0.8 厘米）和枝条长度（0.7 对 0. 1 cm) 与连续 15℃ 下的敏感基因型相比。以最高测试浓度（20 和 25 μM）施用的四种安全剂中的每一种都显着促进了 15℃ 下的种子发芽和幼苗生长。与单独的两种或三种方式的组合相比，四种安全剂的组合在减少寒冷应激引起的损伤方面更有效。在优化遗传背景和农业气候条件对安全剂化学、浓度和种子施用安全剂的适当组合的影响后，增强的耐寒性可能会扩展到其他谷类作物。与单独的两种或三种方式的组合相比，四种安全剂的组合在减少寒冷应激引起的损伤方面更有效。在优化遗传背景和农业气候条件对安全剂化学、浓度和种子施用安全剂的适当组合的影响后，增强的耐寒性可能会扩展到其他谷类作物。与单独的、两种或三种方式的组合相比，四种安全剂的组合在减少寒冷应激引起的损伤方面更有效。在优化遗传背景和农业气候条件对安全剂化学、浓度和种子施用安全剂的适当组合的影响后，增强的耐寒性可能会扩展到其他谷类作物。