The maize doubled haploid (DH) technology plays an important role in accelerating breeding genetic gain. One major challenge in fully leveraging the potential of DH technology to accelerate genetic gain is obtaining a consistent seed return from haploid (DH0) plants after chromosome doubling. Here we demonstrated that DH0 seed production can be increased by increasing the number of mature axillary female inflorescences (ears) at anthesis. To determine the maximum capacity of a maize plant to develop ears, we first characterized the developmental progression of every axillary meristem. We found that all axillary meristems developed to a similar developmental stage before the reproductive transition of the shoot apical meristem (SAM). Upon reproductive transition of the SAM, all axillary meristems are released for reproductive development into ears in a developmental gradient reflective on their positions along the main stem. However, under most circumstances only the top one or two ears can generate silks at anthesis. We found that applying the GA inhibitor paclobutrazol (PAC) during the early reproductive transition of axillary meristems increased the number of silking ears at anthesis, leading to increased success of self‐pollination and seed production. These results provide a blueprint to improve DH efficiency and demonstrate the potential of breeding innovation through understanding crops’ developmental processes.

中文翻译：

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我无所不能：通过促进腋窝分支伸长，使玉米单倍体成功率最大化。

玉米双倍单倍体（DH）技术在加速育种遗传增益中起着重要作用。充分利用DH技术的潜力来加速遗传增益的一个主要挑战是染色体倍增后从单倍体（DH0）植物获得一致的种子返回。在这里，我们证明了通过增加花期成熟腋生雌花序（穗）的数量可以增加DH0种子的产量。为了确定玉米植物发育穗的最大能力，我们首先表征了每种腋生分生组织的发育进程。我们发现，在腋生分生组织（SAM）的生殖过渡之前，所有腋生分生组织均发育至相似的发育阶段。SAM生殖过渡后，所有腋生分生组织均以发育梯度释放到耳朵，以反映它们在主茎上的位置。但是，在大多数情况下，只有一到两个大耳朵才能在花期产生丝。我们发现，在腋生分生组织的早期生殖过渡过程中使用GA抑制剂多效唑（PAC）可以增加花期的穗丝数量，从而提高自花授粉和种子生产的成功率。这些结果提供了改善DH效率的蓝图，并通过了解农作物的生长过程证明了育种创新的潜力。我们发现，在腋生分生组织的早期生殖过渡过程中使用GA抑制剂多效唑（PAC）可以增加花期的穗丝数量，从而提高自花授粉和种子生产的成功率。这些结果提供了改善DH效率的蓝图，并通过了解农作物的生长过程证明了育种创新的潜力。我们发现，在腋生分生组织的早期生殖过渡过程中使用GA抑制剂多效唑（PAC）可以增加花期的穗丝数量，从而提高自花授粉和种子生产的成功率。这些结果提供了改善DH效率的蓝图，并通过了解农作物的生长过程证明了育种创新的潜力。