Guo J J, Xu X X, Zhang R D, Chen X F, Xing Y F, Li B, Liu C, Zhou Y F
College of Agronomy, Shenyang Agricultural University, Shenyang, Liaoning, China.
Tongliao Agricultural Technology Extension Station, Tongliao, Inner Mongolia, China.
Photosynthetica. 2022 Feb 8;60(2):200-211. doi: 10.32615/ps.2021.067. eCollection 2022.
Alkaline stress is important abiotic stress that restricts the growth and physiological activity of sorghum ( L. Moench). We aimed to investigate the effects of alkaline stress on alkali-tolerant SX44B and alkali-sensitive 262B sorghum inbred lines. The results showed that alkaline stress decreased the content of chlorophyll, activity of photosystem II, net photosynthetic rate, and destroyed chloroplast morphology. These changes were less pronounced in SX44B, possibly owing to its higher antioxidant enzyme activity and nonphotochemical quenching. Alkaline stress decreased water content, transpiration rate, and stomatal conductance while increasing the leaf temperature, with the effect being more pronounced in 262B. A significant correlation was observed between leaf-air temperature difference (ΔT) and relative water content and gas-exchange parameters, especially in 262B. Therefore, ΔT is an effective indicator for monitoring changes in sorghum leaves under alkaline stress and evaluating the alkali tolerance of different sorghum germplasm.
碱性胁迫是限制高粱（L. Moench）生长和生理活性的重要非生物胁迫。我们旨在研究碱性胁迫对耐碱自交系SX44B和碱敏感自交系262B高粱的影响。结果表明，碱性胁迫降低了叶绿素含量、光系统II活性、净光合速率，并破坏了叶绿体形态。这些变化在SX44B中不太明显，可能是由于其较高的抗氧化酶活性和非光化学猝灭。碱性胁迫降低了含水量、蒸腾速率和气孔导度，同时提高了叶片温度，这种影响在262B中更为明显。叶气温差（ΔT）与相对含水量和气体交换参数之间存在显著相关性，尤其是在262B中。因此，ΔT是监测碱性胁迫下高粱叶片变化和评估不同高粱种质耐碱性的有效指标。
