**3. QTLs in strawberry**

A QTL is defined as the point or part of coding or non-coding chromosomal regions representing a trait quantitatively. QTL mapping is based on biparental or natural populations and aims at the detection of correlation between phenotypic traits and genomic regions. To carry out the QTL mapping, variant detection in genomic data is completed and phenotypic values are evaluated for each individual in the population. Detection of the chromosomal position related to important genes is one of the major aims of QTL studies. In this section, we will review the previous QTL studies about agronomically important traits that have large effects on strawberry breeding.

In the cultivated octoploid strawberry, the detected QTLs were located at homoeologous loci, meaning each locus can be represented up to four times in the genome as homoeologous loci, each presenting two homologous alleles. These QTLs at homoeologous locations can be considered as homoeo-QTLs [32, 51].
