Controlling pollination of the female inbred is critical to achieve maximum kernel set and high levels of genetic purity in maize (Zea mays L.) hybrid seed production. Although kernel set associated with inbred flowering dynamics is fairly predictable, it has not been possible to predict the level of outcrossing resulting from adventitious pollen entering the seed field. Our objective was to combine our kernel set model with a new Lagrangian pollen dispersal model to determine whether outcrossing could be simulated from flowering dynamics and estimates of pollen drift. This study was conducted in a commercial seed production field in which male and female planting dates were varied to provide a range of flowering synchronies and risk for outcrossing. Kernel production varied from 13.4 x 106 to 24.5 x 106 kernels ha-1. Outcrossing at field locations 100 to 170 m from an adventitious pollen source varied from 1.4 to 18% as determined by allelic variation at 13 loci. The kernel set model accurately simulated variation in kernel production (R2 = 0.83; RMSE = 0.3 x 106) when silk receptivity was limited to 4 d. Percentage outcrossing due to adventitious pollen also was accurately simulated (R2 = 0.78; RMSE = 0.8) for wind conditions and plant development patterns typically encountered in maize hybrid seed production. The combined kernel set and pollen dispersal models provide a novel and robust approach for defining management strategies to optimize kernel production and genetic purity.
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机译：控制雌性自交系的传粉对于在玉米（Zea mays L.）杂交种子生产中获得最大的籽粒集和高水平的遗传纯度至关重要。尽管与近交开花动态相关的籽粒集是相当可预测的，但尚无法预测由于不定花粉进入种子田而引起的异交水平。我们的目标是将我们的核集模型与新的拉格朗日花粉扩散模型结合起来，以确定是否可以根据开花动态和花粉漂移的估计来模拟异型杂交。这项研究是在商业种子生产领域中进行的，在该领域中，雄性和雌性的播种日期均发生了变化，以提供一系列的开花同步性和异交风险。内核产量从13.4 x 106到24.5 x 106内核ha-1不等。由13个位点的等位基因变异确定，从不定花粉来源到野外位置100-170 m的异交率为1.4％至18％。当丝接受度限制为4 d时，籽粒集模型可以精确模拟籽粒产量的变化（R2 = 0.83; RMSE = 0.3 x 106）。还针对风条件和玉米杂交种子生产中通常遇到的植物发育模式，精确模拟了由于不定花粉引起的异交百分比（R2 = 0.78; RMSE = 0.8）。组合的核仁集和花粉传播模型为定义管理策略以优化核仁产量和遗传纯度提供了一种新颖而强大的方法。
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