From Single Nucleotide Polymorphisms to Phenotypes: Comparative Analysis between Genome Wide Association (GWAS) and Quantitative Trait Loci (QTL) Mapping: A Review Article

Abstract

This review provided a broad overview of the basic theory, methodology and applications of Genome-Wide Association Studies (GWAS) and Quantitative Trait Loci (QTL) mapping, two cornerstone technologies in plant genetics. This will be combined with an introduction of GWAS and QTL mapping, emphasizing the function of these methods to identify genetic variations underlying plant complex traits. Additionally, we explored the statistical models behind both methods, understanding the science behind regression models, including linear and logistic regression, but also addressing Type I and Type II errors and methods to minimize them, highlighting the keys such as multiple testing correction, replication and functional validation. the review also showed the practical applications of GWAS and QTL mapping in agriculture, crop improvement, livestock breeding and sustainable farming. Examples like flood resistant rice and drought tolerant maize showed the power of these technologies. Finally, the review discussed the challenges and future directions in the agriculture field including the integration of new technologies like CRISPR and high throughput phenotyping.