Growth temperature and genotype can influence seedling vigor in cotton (Gossypium hirsutum L.), and identifying genotypes that can perform well under different temperature extremes may broaden the range of temperatures over which optimum growth could be obtained. To this end, a controlled environment study was conducted to evaluate the response of advanced breeding lines to growth temperature and to evaluate the utility of rapid, fluorescence-based measurements (the OJIP test) as indicators of plant growth response to day/night temperature regimes (20/15, 30/20, 35/25, and 40/30 °C). At two weeks after planting, growth analysis, chlorophyll fluorescence measurements, and pigment concentrations were obtained. Significant genotype, temperature, and interaction effects were observed for seedling growth parameters, and some of the key components of the thylakoid reactions. Specifically, the 35/25 °C treatment had the highest values for all growth parameters, with genotypic differences in growth primarily being observed at this regime. Energy trapping by photosystem II (PSII) (φ_PO), intersystem electron transport (φ_EO), and photosystem I end electron acceptor reduction (φ_RO) were significantly affected by temperature, but each component differed in heat sensitivity. All growth parameters were significantly correlated with a number of OJIP parameters including quantum efficiencies and performance indices. However, the strongest positive associations were observed between quantum efficiencies and growth metrics, with φ_EO exhibiting the strongest correlations with growth. Our observations indicate that rapid OJIP assessments can potentially be used as indicators of early season growth responses to temperature.

生长温度和基因型对棉花幼苗活力的影响（Gossypium hirsutumL.)，鉴定在不同极端温度下表现良好的基因型可能会拓宽获得最​​佳生长的温度范围。为此，进行了一项受控环境研究，以评估先进育种品系对生长温度的响应，并评估基于荧光的快速测量（OJIP 测试）作为植物生长对昼/夜温度状态响应指标的效用（20/15、30/20、35/25 和 40/30 °C）。种植两周后，获得生长分析、叶绿素荧光测量值和色素浓度。对于幼苗生长参数和类囊体反应的一些关键成分，观察到显着的基因型、温度和相互作用效应。具体来说，35/25 °C 处理的所有生长参数值都最高，主要在这种情况下观察到生长的基因型差异。光系统 II (PSII) (φ_PO )、系统间电子传输 (φ _EO ) 和光系统 I 末端电子受体还原 (φ _RO ) 受温度影响显着，但每种组分的热敏感性不同。所有生长参数都与许多 OJIP 参数显着相关，包括量子效率和性能指标。然而，在量子效率和增长指标之间观察到最强的正相关，φ _EO与增长的相关性最强。我们的观察表明，快速的 OJIP 评估可能被用作早期生长对温度的反应的指标。