Abstract

Male meiosis in temperate fruit trees occurs in the anthers once a year, synchronized with the seasons. The alternation of dormant and growth cycles determines the optimum moment for the male gametophyte formation, a process sensitive to both cold and warm temperatures. This ensures pollen viability and subsequent reproduction success that guarantee fruit production. In this work, we explore how male meiosis is framed by seasonality in sweet cherry. For this purpose, the dormant phases, male meiosis and blooming dates were established in four cultivars with different flowering dates and chilling requirements over 7 years. The chilling and heat requirements for each cultivar were empirically estimated, and chilling and heat temperatures were quantified according to the Dynamic and Growing Degree Hours (GDH) models, respectively. Endodormancy was overcome approximately a fortnight earlier during the colder winters than during the milder winters. Against our initial hypothesis, these differences were not clearly reflected in the time of male meiosis. The period between chilling fulfillment and meiosis lasted several weeks, during which a high amount of GDH accumulated. Results showed that male meiosis is conditioned by endodormancy but especially by warm temperatures, during the forcing period. This differs from what has been described in other related species and creates a framework for further studies to understand the strategies of synchronizing dormancy with seasons.

中文翻译：

---

甜樱桃中的雄性减数分裂受休眠的冷却和强迫阶段的限制

摘要

温带果树中的雄性减数分裂每年在花药中发生一次，与季节同步。休眠和生长周期的交替决定了雄配子体形成的最佳时刻，该过程对寒冷和温暖的温度都敏感。这确保了花粉的生存能力和随后的繁殖成功，从而确保了水果的产量。在这项工作中，我们探索了甜樱桃的季节性如何构成雄性减数分裂。为此，在四个具有不同开花日期和冷藏要求的品种中，在7年中确定了休眠期，雄性减数分裂和开花期。根据经验估算每个品种的冷却和热量需求，分别根据动态和生长小时数（GDH）模型对冷却和加热温度进行量化。与较温和的冬季相比，较冷的冬季大约早了两个星期克服了异味。根据我们最初的假设，这些差异并未在男性减数分裂时清晰反映出来。低温满足和减数分裂之间的时间持续数周，在此期间大量的GDH积累。结果表明，雄性减数分裂受强迫时期内异味的影响，尤其是温暖的温度。这与其他相关物种中描述的不同，并为进一步研究以了解使休眠与季节同步的策略提供了框架。低温满足和减数分裂之间的时间持续数周，在此期间大量的GDH积累。结果表明，雄性减数分裂受强迫时期内异味的影响，尤其是温暖的温度。这与其他相关物种中描述的不同，并为进一步研究以了解使休眠与季节同步的策略提供了框架。低温满足和减数分裂之间的时间持续数周，在此期间大量的GDH积累。结果表明，雄性减数分裂受强迫时期内异味的影响，尤其是温暖的温度。这与其他相关物种中描述的不同，并为进一步研究以了解使休眠与季节同步的策略提供了框架。