Plant Gene and Trait 2024, Vol.15, No.1, 33-43 http://genbreedpublisher.com/index.php/pgt 35 Figure 1 The basic procedure of marker-assisted selection (Adopted from Hasan et al., 2021) Once the correlation between markers and traits has been established, marker-assisted selection can be implemented. In practical breeding, by rapidly screening populations through genotyping and selecting individuals with the desired genetic markers for next generation crossing or breeding, breeders can effectively accumulate favorable genes and accelerate the development of new varieties, especially for traits where phenotypic evaluation is time-consuming or costly. 2.3 Principles of quantitative trait locus (QTL) mapping and its application in MAS Quantitative trait loci (QTL) mapping is a technique used to identify gene regions that control complex genetic traits such as yield, disease resistance or quality for quantitative traits. The rationale relies on statistical analysis methods that can correlate the distribution of genetic markers with variation in phenotypic traits (Diaz et al., 2011). By constructing a genetic linkage map, which includes genetic marker data from individuals in a population, the researchers are able to identify which markers are significantly correlated with the expression of a target trait, indicating that the target trait is likely to be controlled by a specific chromosomal region, which in turn revealed the genes influencing the trait. The application of QTL mapping is very important in marker-assisted selection (MAS). By precisely locating QTLS that control key agricultural traits, breeders can use this information to select individuals with superior genetic backgrounds (Diaz et al., 2011). For example, if a QTL is strongly associated with high yield, then plants containing this QTL can be selected as fathers for future crossbreeding programs to improve the overall yield performance of the offspring population. This method of selection based on genetic information is more efficient than traditional phenotypic selection because it allows breeders to assess the genetic potential of plants at the seedling stage. The application of QTL mapping in MAS is not limited to improving the economic traits of crops, but also extends to a wider range of applications such as disease resistance and adaptability. In rice, for example, multiple gene regions associated with drought resistance were identified through QTL mapping, and this information was then used to develop new varieties with better drought adaptability. In addition, QTL mapping improves the understanding of crop genetic diversity and deepens our understanding of genetic mechanisms, leading to more precise breeding strategies.
RkJQdWJsaXNoZXIy MjQ4ODYzMg==