Abstract Flowering time is the most critical developmental stage in wheat, as it determines environmental conditions during grain filling. Thirty‐five spring durum genotypes carrying all known allele variants at Ppd‐1 loci were evaluated in fully irrigated field experiments for three years at latitudes of 41°N (Spain), 27°N (northern Mexico) and 19°N (southern Mexico). Relationships between weight of central grains of main spikes (W) and thermal time from flowering to maturity were described by a logistic equation. Differences in flowering time between the allele combination causing the earliest (GS100/Ppd‐B1a) and the latest (Ppd‐A1b/Ppd‐B1a) flowering were 7, 20 and 18 days in Spain, northern Mexico and southern Mexico, respectively. Flowering delay drastically reduced the mean grain filling rate (R) and W at all sites. At autumn‐sowing sites, an increase of 1°C in mean temperature during the first half of the grain filling period decreased W by 5.2 mg per grain. At these sites, W was strongly dependent on R. At the spring‐sowing site (southern Mexico), W depended on both R and grain filling duration. Our results suggest that incorporating the allele combinations GS100/Ppd‐B1a and GS105/Ppd‐B1a (alleles conferring photoperiod insensitivity) in newly released varieties can reduce the negative effects of climate change on grain filling at the studied latitudes.

中文翻译：

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Ppd-1位点等位基因组合对不同纬度硬粒小麦灌浆的影响

摘要 开花期是小麦最关键的发育阶段，它决定了籽粒灌浆过程中的环境条件。在北纬 41°（西班牙）、北纬 27°（北墨西哥）和北纬 19°（南墨西哥）的完全灌溉田间试验中，对 35 种春季硬粒小麦基因型进行了评估）。主穗中心粒重 (W) 与开花到成熟的热时间之间的关系通过逻辑方程描述。在西班牙、墨西哥北部和墨西哥南部，导致最早（GS100/Ppd-B1a）和最晚（Ppd-A1b/Ppd-B1a）开花的等位基因组合的开花时间差异分别为 7、20 和 18 天。开花延迟大大降低了所有地点的平均灌浆率 (R) 和 W。在秋播现场，在灌浆期的前半段，平均温度每增加 1°C，每粒 W 减少 5.2 mg。在这些地点，W 强烈依赖于 R。在春播地点（墨西哥南部），W 取决于 R 和灌浆持续时间。我们的结果表明，在新发布的品种中加入 GS100/Ppd-B1a 和 GS105/Ppd-B1a（赋予光周期不敏感性的等位基因）组合可以减少气候变化对研究纬度的籽粒灌浆的负面影响。