Microstructure and tuber properties of potato varieties with different genetic profiles

- Twenty-one potato varieties were studied for microstructural and thermal properties.
- Starch granular size and chemical properties were variety-dependent.
- Particle size and shape of starch granules were evaluated through SEM.
- Genetic profiles were generated for all samples with SSR molecular markers.
- A total of 157 alleles were detected through the analysis of 23 loci.

The objectives of this research were to study tuber starch characteristics and chemical - thermal properties of 21 potato varieties, and to determine their genetic diversity through SSR markers. Starch granular size varied among samples, with a wide diameter distribution (5-85 μm), while granule shapes were similar. Differential Scanning Calorimeter analysis showed that the transition temperatures (69 °C-74 °C) and enthalpies of gelatinization (0.9 J/g-3.8 J/g) of tubers were also variety dependent. SSR analysis allowed the detection of 157 alleles across all varieties, with an average value of 6.8 alleles per locus. Variety-specific alleles were also identified. SSR-based cluster analysis revealed that varieties with interesting quality attributes were distributed among all clusters and sub-clusters, suggesting that the genetic basis of traits analyzed may differ among our varieties. The information obtained in this study may be useful to identify and develop varieties with slowly digestible starch.