Field Crop 2025, Vol.8, No.2, 82-92 http://cropscipublisher.com/index.php/fc 89 6.3 Enhancing breeding efficiency using QTLs and gene-editing technologies The combination of QTL mapping and CRISPR technology has simply equipped potato breeding with a "GPS navigation system "and a" molecular scalpknife "- first, the target gene region is locked by QTL mapping, and then precise editing is carried out by CRISPR (Kim et al., 2017). For instance, the QTL we discovered that controls starch synthesis requires seven or eight generations of breeding in traditional methods. Now, with CRISPR directly editing the key sites, it only takes two or three generations to see results. However, in actual operation, it was found that the editing efficiency of polyploids is much lower than that of diploids, and repeated attempts are often required. Now our team is even more aggressive. By integrating the Bayesian statistical method and conducting hybrid model analysis, we can reduce the QTL interval to a smaller size, thereby enhancing the targeting of CRISPR. Recently, I have been attempting to simultaneously edit multiple QTL loci for both yield and disease resistance. Although it is highly challenging, if successful, the breeding cycle of the variety can be shortened by more than half. Of course, field verification is still indispensable. After all, the final editing effect depends on the performance in the field. 7 Research Challenges and Directions 7.1 Technical bottlenecks in current potato QTL research Conducting QTL research on potatoes is like playing a high-difficulty jigsaw puzzle-the tetraploid genome makes each genetic locus have four sets of alleles, and the effects produced by their combination are so complex that they are a headache. The most typical example is that the same QTL may exhibit completely different effects in different genetic contexts, and even the direction of action can be reversed (Tiwari et al., 2017). Environmental factors have made things even more complicated. The drought-resistant QTLS detected under drought conditions last year may disappear this year if the rainfall is normal. So we had to set up more than ten test sites across the country and continuously track the data for three years (Yang et al., 2019) in order to distinguish which QTLS were "fixed" and which were "changing". Sometimes, a site that is clearly located in the laboratory becomes "invisible" in the field. This kind of interaction between genes and the environment is the most maddening. However, it is precisely these challenges that make potato genetics research so fascinating-after all, the more complex the problem, the more fulfilling it is to solve it. 7.2 Future prospects of high-throughput omics technologies It's really a great time to conduct research on potato QTL now. GWAS technology is like assembling a scanner for genes (Deng and Chen, 2024). There is no need to pre-set candidate regions. A scan across the entire genome can identify associated loci. However, the most impressive is the multi-omics collaboration-genomic data sets the stage, transcriptome and proteome data perform the show, and recently even metabolome data has been added (Ma et al., 2023). Our laboratory has recently discovered that there is a QTL site that controls flavor. It is not obvious on the genome, but metabolome data show that it significantly affects the accumulation of glycoside alkaloids. This multi-dimensional verification has made QTL localization increasingly precise, and now it can even distinguish similar loci on homologous chromosomes. Of course, when the volume of data is large, it can be a headache. Just processing these omics data requires several servers. But seeing the positioning accuracy shrink from a few megabytes of bases to just a few hundred kb, the targeting of breeding has indeed improved by more than one level. 7.3 The necessity of global collaboration and germplasm resource sharing When it comes to potato research, one cannot go it alone. Germplasm banks around the world are like a "treasure chest" (Manrique-Carpintero et al., 2015), especially those local varieties in the remote Andes mountains, which contain many precious genes for disease and drought resistance. Remember that there was a key gene for resisting late blight, which was initially discovered in a local variety in Peru. Now, the collaborative network led by the International Potato Center is doing quite well. Everyone regularly exchanges materials and data and unifies experimental standards-otherwise, the QTLS measured by you might not match mine at all. Recently, a shared database has also been established, where even data on heat-resistant varieties developed by small-scale farmers in Africa can be accessed. The benefits of this open cooperation are obvious: the early-maturing genes from Northern Europe can help improve varieties in South Asia, and disease-resistant materials from the Americas can
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