Cotton fibre yield and quality are markedly influenced by drought and high-temperature stress. We examined the traits of the leaf stomata in 39 cotton genotypes subjected to exogenous phytohormone abscisic acid (ABA) signalling, electrolyte leakage under 40°C thermal stress, and relative GhHsfA, GhbZIP and GhHSP70 expression levels under two treatments. Stomatal density and area ranged from 66 to 182/mm2 and 663 to 1305 μm2, respectively. Under exogenous ABA signalling, the changes in stomatal aperture (ΔSAp) were in the range of 2.5–31.2%; ΔSAp and relative GhHsfA, GhbZIP and GhHSP70 expression levels were significantly correlated, respectively. Electrolyte leakage increased unequally among cotton genotypes after heat stress. The changes in electrolyte leakage (ΔEL) and relative GhHsfA, GhbZIP and GhHSP70 expression levels were very strongly correlated, respectively. Their relative expression levels could be used as references for the rapid identification of stress-tolerant cotton strains. Cluster analysis of the 39 cotton genotypes indicated that Xinluzao36, Shiyang1, shinong98-7 and Zhongmiansuo293 are heat- and drought-resistant. We integrated both analysis of physiological parameters and molecular methods to identify cotton varieties with the drought and heat tolerance, in order to provide a reference for the selection of materials and methods for the research and production of cotton.

中文翻译：

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不同基因型棉花外源ABA和热胁迫耐受性的鉴定

棉花纤维产量和质量受干旱和高温胁迫的影响显着。我们检查了 39 种棉花基因型的叶片气孔特征，这些基因型受到外源植物激素脱落酸 (ABA) 信号、40°C 热应力下的电解质泄漏和相对生长激素,压缩包和GhHSP70两种处理下的表达水平。气孔密度和面积范围为 66 至 182/mm2和 663 至 1305 μm2， 分别。在外源ABA信号下，气孔孔径（ΔSAp）的变化范围为2.5-31.2%；ΔSAp 和相对生长激素,压缩包和GhHSP70表达水平分别显着相关。热应激后不同基因型棉花的电解质渗漏增加不均。电解液泄漏量（ΔEL）和相对变化生长激素,压缩包和GhHSP70表达水平分别非常强烈相关。它们的相对表达水平可作为快速鉴定抗逆棉花品系的参考。对39个棉花基因型的聚类分析表明，新陆早36、石羊1、石农98-7和中棉所293具有抗热抗旱能力。结合生理参数分析和分子方法，鉴定出具有抗旱耐热性的棉花品种，为棉花研究和生产的材料和方法选择提供参考。