positional candidate gene 1 topic · 1 source Science› Biotechnology and GeneticsFood BiotechnologyA gene known to be located in the same region as a DNA marker that has been shown to be linked to a single-locus trait or to a QTL, and whose deduced function suggests that it could be the source of genetic variation in the trait in question.UN Food and Agriculture Organization — Glossary of Biotechnology for Food and Agriculture Cite