In recent years, the frequency and intensity of exposure to heat stress have increased gradually, seriously hampering the production of maize. This paper presents a study designed to analyze how the development, physiology and dispersal of pollen from the heat‐resistant maize variety Zhengdan958 and the heat‐sensitive maize variety Xianyu335 are affected by exposure to heat stress during the tasselling stage. Our results showed That exposure to heat stress significantly increased the antioxidant enzyme activity in pollen. Upon visual inspection of the pollen, we found that the lower water content had given rise to wrinkles in the pollen surface, sunken germination pores, and morphological deformations. In addition, the anther dehiscence process was hindered, resulting in a reduced amount of pollen being dispersed. We also found elevated levels of abscisic acid (ABA), jasmonic acid (JA) and its derivatives, indole acetic acid (IAA) and gibberellin‐3 (GA3) in heat‐pollens, as well as elevated ratios of IAA to ABA and ABA to GA3. Ultimately impaired pollen fertility. Summarizing, our experiment revealed that reduced pollen quantity and quality are significant contributors to fertility losses in summer maize exposed to heat stress at anthesis, and we hope that our analysis of the physiological mechanisms involved can contribute to the development of crop management measures aimed at countering the increasingly detrimental effects of heat stress on the production of summer maize.

中文翻译：

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热应激引起的夏玉米（Zea mays L.）的生育力丧失：对花粉发育和生理损伤的贡献的定量分析

近年来，热胁迫发生的频率和强度逐渐增加，严重影响了玉米的生产。本文提出了一项研究，旨在分析耐热玉米品种郑单958和热敏玉米品种先玉335花粉的发育、生理和传播如何受到抽雄阶段热应激的影响。我们的结果表明，暴露于热应激显着增加了花粉中的抗氧化酶活性。目视观察花粉，发现含水量较低导致花粉表面出现皱纹、发芽孔凹陷、形态变形。此外，花药开裂过程受到阻碍，导致花粉散布量减少。我们还发现脱落酸 (ABA)、茉莉酸 (JA) 及其衍生物、吲哚乙酸 (IAA) 和赤霉素-3 (GA) 水平升高3）在热花粉中，以及 IAA 与 ABA 和 ABA 与 GA 的比例升高3。最终损害花粉育性。综上所述，我们的实验表明，花粉数量和质量的降低是夏玉米在花期受到热胁迫时肥力损失的重要原因，我们希望我们对所涉及的生理机制的分析能够有助于制定旨在应对的作物管理措施。热应激对夏玉米生产的不利影响日益严重。