Rapid cycle genomic selection (RC‐GS) helps to shorten the breeding cycle and reduce the costs of phenotyping, thereby increasing genetic gains in terms of both cost and time. We implemented RC‐GS on two multi‐parent yellow synthetic (MYS) populations constituted by intermating ten elite lines involved in each population, including four each of drought and waterlogging tolerant donors and two commercial lines, with proven commercial value. Cycle 1 (C₁) was constituted based on phenotypic selection and intermating of the top 5% of 500 S₂ families derived from each MYS population, test‐crossed and evaluated across moisture regimes. C₁ was advanced to the next two cycles (C₂ and C₃) by intermating the top 5% selected individuals with high genomic estimated breeding values (GEBVs) for grain yield under drought and waterlogging stress. To estimate genetic gains, population bulks from each cycle were test‐crossed and evaluated across locations under different moisture regimes. Results indicated that the realised genetic gain under drought stress was 0.110 t ha⁻¹ yr⁻¹ and 0.135 t ha⁻¹ yr⁻¹, respectively, for MYS‐1 and MYS‐2. The gain was less under waterlogging stress, where MYS‐1 showed 0.038 t ha⁻¹ yr⁻¹ and MYS‐2 reached 0.113 t ha⁻¹ yr⁻¹. Genomic selection for drought and waterlogging tolerance resulted in no yield penalty under optimal moisture conditions. The genetic diversity of the two populations did not change significantly after two cycles of GS, suggesting that RC‐GS can be an effective breeding strategy to achieve high genetic gains without losing genetic diversity.

中文翻译：

---

通过快速周期基因组选择获得的遗传增益，可综合应对热带玉米的干旱和涝灾（Zea mays L.）

快速循环基因组选择（RC‐GS）有助于缩短育种周期并降低表型鉴定的成本，从而在成本和时间上增加遗传增益。我们在两个多父本黄色合成（MYS）种群上实施了RC-GS，这是通过确定每个种群涉及的十个精英系，其中包括四个耐旱耐涝的捐助者以及两个具有证明的商业价值的商业系。周期1（C ₁）是根据表型选择和确定来自每个MYS群体的500个S ₂家族的前5％进行确定的，经过交叉测试并在不同的水分状况下进行了评估。C ₁前进到接下来的两个循环（C ₂和C ₃），以确定在干旱和涝灾胁迫下谷物产量高的基因组估计育种值（GEBV）高的前5％选定个体。为了估算遗传增益，对每个周期的种群数量进行了测试，并在不同湿度条件下的各个位置进行了评估。结果表明，MYS-1和MYS-2在干旱胁迫下实现的遗传增益分别为0.110 t ha ^-1 yr ^-1和0.135 t ha ^-1 yr ^-1。在淹水胁迫下，增益较小，其中MYS-1显示为0.038 t ha ^-1 yr ^-1，而MYS-2显示为0.113 t ha ^-1 yr ^-1。抗旱和抗涝的基因组选择在最佳水分条件下不会导致产量损失。经过两个周期的GS，两个种群的遗传多样性没有显着变化，这表明RC-GS可以成为实现高遗传增益而不丧失遗传多样性的有效育种策略。