Maize Genomics and Genetics 2025, Vol.16, No.2, 60-69 http://cropscipublisher.com/index.php/mgg 63 3.4 Development and sharing of global germplasm databases When it comes to germplasm research, there have been great changes in recent years. I remember that in the past, each region managed its own data, but now there is a global database, the situation is much better. Although the system needs to be improved, these databases are indeed very practical, with everything from phenotypic to genotypic data (Andorf et al., 2019). The advancement of sequencing technology is also a key factor, which has greatly improved the quality of data. Of course, there are still some minor problems in the specific operation, but for breeding and conservation work, being able to share these resources has been a great help. After all, making good use of this genetic information is very important for solving food security problems. 4 Progress in Utilizing Fresh Corn Germplasm Resources 4.1 Development and utilization of high-quality traits Fresh corn breeding now focuses on several key points - it must be sweet enough, sticky, and disease-resistant. Although progress in disease resistance is relatively slow, there have indeed been many breakthroughs in improving sweetness and stickiness. For example, studies have found that the sh2 gene has a great influence on sweetness (Ruanjaichon et al., 2021), while the qWx9 locus can effectively distinguish between sticky and non-sticky varieties (Ruanjaichon et al., 2022). GWAS analysis is also very useful, helping us quickly identify key genetic markers (Hou et al., 2024). However, the good results in the laboratory may not be the same when they are actually planted in the field, and they still have to go through a lot of tests and verifications in the middle. 4.2 Utilization of stress-resistant traits Now, stress resistance has become a top priority in corn breeding. The climate is becoming more and more unstable, and problems such as drought and salinity are becoming more and more common (Cai et al., 2024). CIMMYT has done a good job in this regard. They have promoted a number of stress-resistant varieties in Africa and Asia, and the field test results are quite good (Prasanna et al., 2021). However, when it comes to drought resistance research, Badr's experiment is quite interesting - using PEG to simulate drought, the higher the concentration, the worse the corn grows (Figure 2) (Badr et al., 2020). The study clearly shows this change. Interestingly, some particularly drought-resistant materials were found through screening. Although the number is small, it at least provides a direction for subsequent breeding. Of course, whether these varieties can adapt to the actual planting environment depends on their field performance. Figure 2 Photographs illustrating the impact of 10% and 15% PEG treatments on 21 days old seedlings of maize accessions (Adopted from Badr et al., 2020) Image caption: (A) control, (B) 10% PEG, (C) 15% PEG (Adopted from Badr et al., 2020) 4.3 Development of nutritional traits When it comes to nutritional improvement of corn, people actually paid more attention to yield issues in the early years (Jompuk et al., 2020). But now the situation has changed a bit, and researchers have begun to focus on improving trace elements such as zinc and vitamin A-although work on reducing the glycemic index is still ongoing. Interestingly, by combining different mutants, such as putting the shrunken2 (sh2), purple (Pr1) and
RkJQdWJsaXNoZXIy MjQ4ODYzNA==