Haploids are naturally produced in maize (Zea mays L.) at different rates and can also be induced through different methods. Haploids are used to develop doubled haploids (DHs), which have many potential uses. The development of DH lines in maize involves haploid induction, haploid identification, chromosome doubling, and field sowing for self‐pollination of D₀ plants. Different potential methods are used for haploid induction, in‐vivo maternal haploid induction being the most prevalent. Haploid induction is highly reliant on the unambiguous identification of haploids among a mixture of different ploidies. Haploid identification is facilitated by visual morphological markers, chromosome counting, flow cytometry, molecular markers, and many other approaches. Chromosome doubling may be achieved by spontaneous doubling or by induction with different antimicrotubular treatments. Among the potential uses of DH lines are the development of inbred lines, genomic selection (GS), quantitative trait loci (QTL) mapping, and unlocking new genetic variations. Although DH technology can potentially accelerate maize breeding, it still faces challenges at each step of DH line development. This article aims to highlight the importance, procedural steps, potential opportunities, and key challenges in DH line development in maize.

中文翻译：

---

玉米单倍体倍增：开发，部署和挑战

单倍体天然地以不同的速率在玉米（Zea mays L.）中产生，也可以通过不同的方法诱导。单倍体用于开发双倍单倍体（DHs），其具有许多潜在用途。玉米DH系的发育涉及单倍体诱导，单倍体鉴定，染色体加倍和田间播种，以实现D _0的自花授粉植物。单倍体诱导使用了不同的潜在方法，体内母体单倍体诱导最为普遍。单倍体诱导高度依赖于不同倍体混合物中单倍体的明确鉴定。视觉形态标记，染色体计数，流式细胞仪，分子标记和许多其他方法可促进单倍体鉴定。染色体加倍可以通过自发加倍或通过不同抗微管治疗的诱导来实现。DH系的潜在用途包括近交系的开发，基因组选择（GS），数量性状基因座（QTL）定位和解锁新的遗传变异。尽管DH技术可以潜在地促进玉米育种，但在DH系开发的每个步骤中仍然面临挑战。