Water stress is the most significant environmental stress in agriculture worldwide.
Potato (Solanum tuberosum L.) is a drought-susceptible crop. Water stress tolerance
is a complex trait of increasing importance in potato. The objective of this work
was to evaluate the differential response strategies associated with water stress
tolerance in a highly diverse potato panel. Multienvironment trials were assessed,
both in field and in glasshouse with contrasting water regimes. The yield, dry matter,
and frying ability were measured in the field assays, whereas proline concentration
(PrC), relative water content (RWC), and water consumption (WC) were measured in the
glasshouse assays. A mixed linear model and ANOVA were performed. The best linear
unbiased predictors (BLUPs) of every genotype for each measured variable were estimated.
Pearson correlation coefficient (r) and principal component analysis (PCA) assessed
the association among traits. The genotypes were ranked by their BLUPs values. The
high diversity potato panel showed variability both in the response to water stress
and within each water regime. In general, Solanum tuberosum spp. andigena genotypes
were associated with the lowest PrC and higher yield, WC, and RWC. By using BLUPs,
a panel of genotypes with good performance under water deficit was defined. This paper
provides knowledge useful to design breeding strategies to water stress tolerance
and new physiological research lines. The utilization of the elite genotypes identified
in this study as progenitors constitute a starting point for breeding programs oriented
to develop water-stress-tolerant varieties.