With the increase in high temperature intensity and occurrence frequency, heat stress has become the main threat to the production of majority of crops, including maize (Zea mays L.). Maize husks play protective and energy-providing roles in ear growth; however, the effects of the husk as well as the response of husk traits to heat stress are not fully understood. To address this gap, a series of experiments were conducted to explore the impacts of heat stress during flowering on husk inside temperature and husk functions and identify the difference in husk response between different tolerant genotypes. Husk inside temperature was lower than the air temperature, and the temperature difference between the outside and inside of the husk (T_outside – T_inside) increased with the increased air temperature and reached a maximum (2.5–3.0 °C) at 40/30 °C. The increased stomatal conductance and transpiration rate of husks could contribute to cooling the inside temperature under heat stress. Additionally, a higher husk inside temperature, larger yield losses, and decreased photosynthesis rate were found after manual removal of partial husks, which contributed to reduced husk protection and energy supply effects, especially exposure to heat stress. Under heat stress, heat-tolerant genotypes (i.e., lower yield losses) correspond to lower husk inside temperature, which could be related to the positive response of husk traits to heat stress, including increased/unchanged husk areas, length, width, weight and numbers. In contrast, heat-sensitive genotypes (i.e., higher yield losses) corresponding to higher husk inside temperature and reduction in the above husk parameters. Thus, husk traits that positively respond to heat stress can alleviate the increase in kernel temperature and further decrease yield damage. Considering appropriate husk traits and understanding the potential heat tolerance mechanism have implications for breeding and screening tolerant genotypes under future warmer climates.

随着高温强度和发生频率的增加，热胁迫已成为包括玉米（ Zea mays L.）在内的大多数农作物生产的主要威胁。玉米壳在穗的生长中起到保护和提供能量的作用；然而，外壳的影响以及外壳特性对热应激的反应尚不完全清楚。为了解决这一差距，进行了一系列实验来探索开花期间热应激对果壳内部温度和果壳功能的影响，并确定不同耐受基因型之间果壳反应的差异。稻壳内部温度低于空气温度，稻壳内外温差(T _outside – T _inside) 随着空气温度的升高而增加，并在 40/30 °C 时达到最大值 (2.5–3.0 °C)。壳的气孔导度和蒸腾速率增加可能有助于在热胁迫下冷却内部温度。此外，在手动去除部分外壳后发现外壳内部温度较高，产量损失较大，光合速率降低，这有助于降低外壳保护和能量供应效果，特别是暴露于热应激。在热胁迫下，耐热基因型（即较低的产量损失）对应于较低的稻壳内部温度，这可能与稻壳性状对热胁迫的积极反应有关，包括增加/不变的稻壳面积、长度、宽度、重量和数字。相反，热敏基因型（即 更高的产量损失）对应于更高的外壳内部温度和上述外壳参数的降低。因此，对热胁迫有积极反应的壳性状可以缓解籽粒温度的升高，进一步降低产量损害。考虑适当的外壳特性和了解潜在的耐热机制对在未来变暖的气候下培育和筛选耐热基因型具有重要意义。