Step 1: Define QTL mapping.
QTL stands for Quantitative Trait Loci, which are genomic areas linked to quantitative characteristics like height, yield, or disease resistance.
Step 2: Historical context.
Sax's 1923 research was the inaugural demonstration of the connection between a Mendelian marker gene and a quantitative trait, thereby establishing the groundwork for QTL mapping.
Step 3: Evaluation of candidates.
- Stern: Recognized for studies on genetic recombination, not QTL.
- Sax: Accurate; his 1923 work established a link between seed coat color and seed size in beans.
- Mather: Contributed to the understanding of polygenic inheritance.
- Galton: Focused on biometrics and heredity, but not QTL mapping.
Step 4: Final determination.
Consequently, QTL mapping was initially documented by Sax in 1923.