Molecular Plant Breeding 2024, Vol.15, No.3, 100-111 http://genbreedpublisher.com/index.php/mpb 101 2 Development of MAGIC Populations 2.1 Historical development of MAGIC populations in plant breeding The concept of MAGIC populations represents a significant evolution in plant breeding methodologies. Historically, plant breeding has relied on bi-parental crosses to combine desirable traits. However, the advent of MAGIC populations has expanded the genetic horizons by incorporating alleles from multiple founder parents into a single population. This approach has been increasingly adopted across various crops, including cereals, legumes, and vegetables, to enhance genetic diversity and improve complex traits (Cavanagh et al., 2008; Bandillo et al., 2013; Meng et al., 2016; Ongom and Ejeta, 2017; Huynh et al., 2018; Campanelli et al., 2019; Arrones et al., 2020; Mangino et al., 2021; Samineni et al., 2021; Singh and Shrivastav, 2023). 2.2 Genetic principles and breeding strategies involved in creating MAGIC populations MAGIC populations are constructed by intercrossing a number of diverse founder lines, followed by several generations of mating, which can include both structured and random matings. The resulting RILs are a genetic mosaic of the founder genomes, providing a rich resource for genetic analysis and breeding. The development of these populations can follow "funnel" or "diallel" cross-designs, ensuring a balanced representation of each parent's genome (Huynh et al., 2018; Arrones et al., 2020). The use of advanced genotyping technologies, such as genotyping-by-sequencing (GBS), has facilitated the characterization of these complex populations (Bandillo et al., 2013; Ongom and Ejeta, 2017). The genetic makeup of MAGIC populations allows for the fine mapping of QTLs and the identification of novel alleles for trait improvement (Cavanagh et al., 2008; Samineni et al., 2021). 2.3 Comparison with traditional and other contemporary breeding methodologies Compared to traditional bi-parental crosses, MAGIC populations offer a higher level of recombination and allelic diversity, which is advantageous for dissecting complex traits (Bandillo et al., 2013; Arrones et al., 2020). Unlike other contemporary breeding methods, such as genome-wide association studies (GWAS) that rely on natural populations, MAGIC populations are specifically designed with breeding goals in mind, combining desirable traits from elite breeding lines (Cavanagh et al., 2008). This targeted approach, along with the lack of genetic structure and high phenotypic diversity, makes MAGIC populations a more powerful tool for both gene discovery and the direct enhancement of breeding populations (Meng et al., 2016; Huynh et al., 2018; Campanelli et al., 2019; Mangino et al., 2021; Singh and Shrivastav, 2023). The development of MAGIC populations, despite being resource-intensive, has led to the identification of strong associations and candidate genes for important agronomic traits, thereby contributing to the development of advanced varieties (Mangino et al., 2021; Samineni et al., 2021; Singh and Shrivastav, 2023). In conclusion, the development of MAGIC populations marks a significant milestone in the history of plant breeding, offering a sophisticated tool for expanding genetic diversity and improving crop traits. The strategic intercrossing of multiple parents and the application of advanced genetic analysis have positioned MAGIC populations as a cornerstone for future breeding efforts aimed at meeting global agricultural demands. 3 Advantages of Using MAGIC Populations 3.1 Enhanced genetic diversity and its impact on breeding MAGIC populations are a revolutionary step in plant breeding, offering a genetic mosaic derived from multiple founder parents. This results in high genetic and phenotypic diversity, which is essential for the exploitation of plant genetic resources (Arrones et al., 2020). The development of MAGIC populations in crops like cowpea has incorporated a wide array of traits from genetically diverse founders, including resistance to abiotic and biotic stresses, seed quality, and agronomic traits (Huynh et al., 2018). This diversity is a cornerstone for breeding programs aiming to improve crop varieties by combining desirable traits from different lines. 3.2 Improved resolution of QTLs mapping MAGIC populations have proven to be powerful tools for the dissection of complex traits. The sorghum MAGIC population, for example, has shown that a significant proportion of founder alleles segregate within the population, allowing for high-resolution mapping of QTLs (Ongom and Ejeta, 2017). Similarly, in eggplant, the development of a MAGIC population has enabled the identification of strong associations and candidate genes for anthocyanin
RkJQdWJsaXNoZXIy MjQ4ODYzMg==