Thermal stress at the reproductive stage poses a substantial constraint on cereal production worldwide. This study was conducted to assess tolerance to terminal high-temperature stress in 45 wild (Hordeum vulgare ssp. spontaneum) genotypes, 4 cultivars (H. vulgare ssp. vulgare), 98 F3 and 79 BC1F2 families derived from hybridization of the most tolerant wild genotype and a susceptible cultivar Mona. Results of analysis of variance showed the significant genotypic and high-temperature stress effects on all the traits studied. In contrast to the cultivated genotypes, the wild ones were found less affected by high-temperature stress. The multivariate analysis highlighted the additional high-temperature tolerance components in the tolerant families and wild genotypes. Grain yield strongly correlated (p less than 0.01) with stress tolerance, yield stability, and heat tolerance indices. The reduction in the reproduction period caused by high-temperature was much higher in cultivated genotypes than in wild ones. In conclusion, the ingenuous-focused strategies like escape/avoidance are being used primarily to cope with heat stress by cultivars, while adaptive-focused coping strategies such as tolerance are being implemented by wild barley.

中文翻译：

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用于鉴定栽培和野生大麦基因型耐热性的新耐性指数

生殖阶段的热应激对全世界谷物的生产构成了重大制约。这项研究的目的是评估对45种野生（Hordeum vulgare ssp。vulgare）基因型，4个品种（H. vulgare ssp。vulgare），98个F3和79个BC1F2家族的耐受终末高温胁迫的耐受性基因型和易感品种Mona。方差分析结果表明，基因型和高温胁迫对所有研究性状均具有显着影响。与栽培基因型相反，发现野生基因型受高温胁迫的影响较小。多元分析强调了耐性家族和野生基因型中额外的耐高温成分。籽粒产量与胁迫耐受性密切相关（p小于0.01），产量稳定性和耐热性指数。栽培基因型由于高温导致的繁殖期减少远高于野生基因型。总而言之，像逃避/避免这样的以独创为重点的策略主要用于应对品种的热胁迫，而野生大麦则采用了以适应性为重点的应对策略，例如耐受性。