Molecular Plant Breeding 2025, Vol.16, No.2, 146-155 http://genbreedpublisher.com/index.php/mpb 151 hybrids, thereby significantly speeding up the breeding process compared to conventional methods (Dwivedi et al., 2015; Chaikam et al., 2019; Meng et al., 2021). This rapid generation of homozygous lines allows for quicker selection and deployment of disease-resistant varieties, which is essential in combating the various biotic stresses that maize faces, such as Fusarium and Gibberella ear rots (Miedaner et al., 2020; Akohoue and Miedaner, 2022). Moreover, the integration of genomics-assisted breeding with DH technology enhances the precision of selecting high-quality resistant varieties. Genomics-assisted breeding allows for the identification of stable quantitative trait loci (QTL) associated with disease resistance, which can be effectively incorporated into breeding programs to improve selection efficiency (Miedaner et al., 2020; Akohoue and Miedaner, 2022). This combined approach ensures that the improved maize varieties are not only resistant to diseases but also possess other desirable agronomic traits, thus providing a comprehensive solution to the challenges faced by maize breeders (Wang et al., 2019; Prasanna et al., 2021). 6.2 Limitations in technology and resources Despite the numerous advantages, the integrated strategy also faces several limitations, particularly in terms of technology and resources. One of the primary challenges is the high cost associated with DH breeding. The process of inducing haploids and subsequently doubling their chromosomes often involves expensive and toxic chemicals, which can be a significant barrier for small-scale breeding programs, especially in developing countries (Kleiber et al., 2012; Chaikam et al., 2019). Additionally, the need for specialized equipment and expertise further adds to the cost and complexity of DH technology (Dwivedi et al., 2015). Access to diverse germplasm resources is another critical limitation. The success of germplasm innovation relies heavily on the availability of a wide range of genetic material. However, obtaining and maintaining such a diverse germplasm pool can be challenging due to regulatory, logistical, and financial constraints (Kleiber et al., 2012). Furthermore, the integration of new germplasm into existing breeding programs requires extensive testing and adaptation, which can be time-consuming and resource-intensive (Miedaner et al., 2020; Prasanna et al., 2021). 6.3 Solutions and technology optimization To overcome these limitations, several solutions and technological optimizations can be implemented. One promising approach is the development of haploid inducers with higher induction rates and better adaptation to different environments. This can reduce the reliance on artificial chromosome doubling and lower the overall cost of DH line production (Kleiber et al., 2012; Chaikam et al., 2019). Additionally, advancements in marker systems for haploid identification, such as the red root marker and high oil marker, can improve the efficiency and accuracy of haploid selection, making the technology more accessible and cost-effective (Chaikam et al., 2019). Another solution is the integration of genomics-assisted breeding with DH technology. By leveraging high-throughput phenotyping and precise genotyping, breeders can more effectively identify and select for disease-resistant traits, thus reducing the time and resources required for developing new varieties (Figure 3) (Miedaner et al., 2020; Akohoue and Miedaner, 2022). Public-private partnerships and multi-institutional collaborations can also play a crucial role in addressing resource constraints. These collaborations can facilitate the sharing of germplasm resources, expertise, and funding, thereby enhancing the overall efficiency and effectiveness of breeding programs (Wang et al., 2019; Prasanna et al., 2021). 7 Future Research Directions and Application Prospects 7.1 Development of efficient haploid induction technology The development of efficient haploid induction technology holds significant promise for enhancing disease-resistant breeding in maize. Doubled haploid (DH) technology has already revolutionized maize breeding by enabling the rapid production of pure lines, which are crucial for heterosis utilization and hybrid development (Chaikam et al., 2019; Meng et al., 2021). Recent advancements in haploid induction, such as the development of haploid inducers with high haploid induction rates (HIR) and the integration of new marker systems for haploid identification, have further improved the efficiency and accessibility of DH technology (Chaikam et al., 2018; Chaikam et al., 2019). These advancements can significantly accelerate the breeding process, allowing for quicker
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