Field Crop 2025, Vol.8, No.2, 82-92 http://cropscipublisher.com/index.php/fc 83 the relevant gene regions are identified, it will still take a lot of effort to determine exactly which gene is at work. Important characteristics such as yield and disease resistance (Massa et al., 2015) are often the result of the combined action of multiple genes. The commonly used approach nowadays is to develop molecular markers, so that during breeding, it can be known in advance which seedlings may be more outstanding. Of course, in actual operation, various unexpected situations will still be encountered. After all, living beings are just too complex. But in any case, this technology has indeed saved a lot of time for breeding experts. This research mainly focuses on several key indicators of potatoes-yield, quality, as well as disease and drought resistance. To be honest, these characteristics cannot be determined by just one or two genes. Therefore, we use QTL mapping to understand the genetic patterns behind them. Although the mechanism of action of some sites has not been fully understood yet, some important associated regions have indeed been identified. With these discoveries, we will be able to select materials more precisely when doing breeding in the future. Of course, practical application may still need to be combined with traditional breeding methods. After all, there will always be some unexpected situations in the field performance. Overall, however, these data should be helpful for cultivating more high-yielding and disease-resistant potato varieties, especially in the current situation where climate change is so frequent. Ultimately, the most important thing is to be able to truly apply the laboratory achievements to the fields and enable farmers to grow better potatoes. 2 Materials and Methods 2.1 Study materials: germplasm sources and target trait selection criteria The materials used in this experiment are quite interesting. They were obtained by crossing the processing 12601ab1 and the fresh potato Stirling parents. To be honest, there are certain considerations when choosing these two parents. One is good at processing characteristics, and the other has good edible quality. The purpose is to see if the offspring can inherit both advantages. Finally, 227 different hybrid offspring were obtained, each of which looked quite different-some had particularly high yields, some had very regular tuber shapes, and some had particularly good disease resistance (Hurtado-Lopez et al., 2015). We focused on observing several practical traits: the yield level, whether the tubers were round or not, the dry matter content, and whether they could be harvested early. These indicators are very practical for both growers and processing plants. After all, who wouldn't want potatoes that are both high-yielding and good-looking? However, to be fair, the manifestations of these traits in hybrid offspring are truly diverse, and some combinations are completely unexpected. 2.2 Phenotypic measurement and evaluation methods for key traits To ensure the reliability of the data, we have made a lot of efforts. These potatoes have been grown for a full three years and in different places-after all, the performance of the same variety can vary greatly in different environments. Each harvest is carried out according to a uniform standard. For instance, the yield is calculated by digging out and weighing each potato plant honestly. The shape of the tubers is rather interesting. It has to be examined one by one by hand, mainly to see if they are round and if the eyes of the sprouts are deep. Sometimes, there can be a long argument over a "standard appearance" potato (Yamakawa et al., 2021). The dry matter content is really high. Just slice the potatoes, dry them and weigh them. As for early maturity, we would walk around the fields every day to see when half of the plants had flowered. To be honest, this kind of field work is the most exhausting, but the data quality is indeed much more reliable than that of laboratory data alone. 2.3 Construction of genetic linkage maps and selection of marker types When it comes to constructing the genetic map, we have put all the available marker techniques to use. At the very beginning, I used AFLP markers and spent a long time fiddling with 38 sets of primers. Later, six more SSR tags were added. Although these traditional techniques are time-consuming, the results are quite stable. However, the most powerful part was the SNP markers added later, which involved several thousand genome-wide loci at once (Hu et al., 2020), significantly improving the resolution of the map. The final map pieced together contains 514 valid markers, divided into 12 linkage groups-this number is quite interesting and exactly matches the chromosome number of potatoes. To be honest, the most annoying thing about making a graph is that some markers just won't obediently join the chain group no matter what, and you have to verify them repeatedly.
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