Field Crop 2025, Vol.8, No.4, 166-175 http://cropscipublisher.com/index.php/fc 170 6 Implications for Breeding and Conservation 6.1 Utilizing genetic structure information to broaden the breeding base When choosing corn germplasm, if one only focuses on the ready-made materials, many potential resources will be overlooked. Genetic structure analysis can help people see further, identify and apply those diverse local and traditional varieties, so that the foundation of breeding will not be too single. The European Maize Evaluation Network once conducted a large-scale classification, dividing 626 local varieties into several different groups, and found that the differences were much greater than expected (Balconi et al., 2024). These differences are not insignificant decorations; on the contrary, they can be used to breed new varieties that are drought-resistant, disease-resistant and suitable for local conditions. Climate change is becoming increasingly evident. If this diversity is not incorporated into breeding programs, it will be even more difficult to ensure the sustainability of agriculture. 6.2 Identifying underrepresented germplasm for targeted introgression Some gene banks are rarely dealt with passively in breeding, but this does not mean they are of no value. Through genetic and phenotypic assessment, those underrepresented or unique resources can be identified, which may precisely contain the key traits that are missing in the existing breeding lines. For instance, local varieties from Latin America or the highlands often have genes that can adapt to the local environment. Introducing them selectively into breeding not only enhances stress resistance and nutritional quality but also enables corn to adapt to some regions where the original growth conditions were not ideal (Prasanna et al., 2021). This approach is of great help in meeting the needs of small-scale farmers and different agricultural ecological zones. 6.3 Conservation strategies for maintaining genetic diversity in situ and ex situ The methods for protecting germplasm are not singular. In-situ conservation involves preserving local and traditional varieties in farmlands, often associated with small-scale farming, traditional food production, and farming in remote areas. This enables genetic diversity and local adaptability to persist (Guzzon et al., 2021). Rather than in-situ conservation, such as collecting germplasm into gene banks and establishing core sets, it is more suitable for long-term preservation and future breeding research. In addition, if more market opportunities can be provided for local varieties or farmers can be encouraged to participate in breeding, it will also increase their willingness to continue growing and utilizing these diverse varieties. 7 Case Study 7.1 Historical introduction and adaptation In the 16th century, corn was introduced to Africa from the Americas and quickly adapted to different agricultural ecological zones in Africa. In sub-Saharan Africa, breeding projects have been developing early-maturing and ultra-early-maturing varieties suitable for local conditions since then, which has accelerated the promotion of corn and enhanced its role in food security (Nelimor et al., 2020). In Latin America, corn is a native crop and has a deep historical connection with the local area. For thousands of years, local farmers have continuously selected and improved local varieties to enable them to grow in various environments such as lowlands and highlands (Guzzon et al., 2021). Latin America remains the core region of global corn diversity to this day, and the local varieties here are of great significance to food security and cultural heritage. 7.2 Comparative analysis of genetic diversity patterns In Africa, the germplasm resources of corn are very complex, and the varieties vary greatly from place to place. Especially for local varieties and superior strains, their genetic diversity is very high and their population structure is not simple either. These differences are sometimes related to the history of breeding, and sometimes linked to the origin of ancestors and adaptability to the local environment. Studies in West Africa and South Sudan have shown that the differences within populations are quite obvious, and the degree of gene pool differentiation among regions ranges from medium to high. The local varieties of Burkina Faso are a typical example, not only with prominent differentiation but also with very limited gene flow between them and improved strains (Mathiang et al., 2022). The situation in Latin America is a different pattern. Analysis of local populations reveals that there are three main groups that can reflect historical migrations and exchanges: the Mexican/Southern Andes population,
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