There is a growing niche market for coloured-skin potatoes with breeders looking to develop new cultivars with coloured skin, as well as improved agronomic and nutritional traits.
While skin colour can be determined visually, it’s not possible to visually determine whether white-skinned varieties have the potential to bear coloured progeny or to estimate the dosage of gene variants associated with tuber skin colour.
Using genetic molecular markers provides a time- and money-saving tool that can increase the efficiency of conventional plant breeding programmes through marker-assisted selection (MAS) of both parents and elite seedlings in breeding populations.
The study Development and application of high-resolution melting DNA markers for the polygenic control of tuber skin colour in autotetraploid potato
used next-generation sequencing and high-resolution DNA melting (HRM) to develop single nucleotide polymorphism (SNP)-based markers from candidate genes associated with skin colour in cultivated potatoes. DNA melting markers discriminate between different variants of a single gene that associate with the tuber skin colour, which is important since cultivated tetraploid potatoes have four sets of chromosomes.
The study developed markers at three loci (physical locations of the genes) that contribute to potato skin colour. These markers can be used together to determine gene variant dosage which allows breeders to select varieties with the right gene combinations that when crossed will produce progeny with skin colour. Marker-assisted selection can also be used to test progeny and predict skin colour before they produce tubers, thus saving time and space on the farm.
