Stability of Potato Clones Under Different Climatic Conditions

The influence of the environment on genotype × environment (G×E) interaction plays a key role in yield variation. Among the most impactful factors are temperature increase and changes in rainfall patterns, which directly affect tuber development. Studies indicate that climate change could reduce global potato (Solanum tuberosum L.) production by 18-32% in the absence of adaptation strategies, and by 9-18% with mitigation measures. In this context, the Vegetable Breeding Laboratory (LMH) at ESALQ/USP has developed research aimed at obtaining cultivars with high performance and yield stability, targeting industrial processing and climate resilience. Therefore, this study aimed to identify potato clones with stable performance across different growing seasons, even under contrasting climatic conditions. A total of 72 potato clones from the LMH breeding program were evaluated. The experiments were conducted at the ESALQ/USP Experimental Farm of Genetics during the 2024/25 growing season, across three distinct growing periods: (I) before the ideal season, under high temperatures (ENV1); (II) during the ideal season (ENV2); and (III) after the ideal season (ENV3). The randomized block design with two replications was used, and commercial yield was evaluated. Stability analysis was based on the WAASB index (Weighted Average of Absolute Scores from the singular value decomposition of the BLUP matrix of GEI effects) (Olivoto et al., 2019), performed in R software (version 4.4.1) using the metan package. The WAASB biplot combines estimates of mean productivity and stability, classifying genotypes into four groups: (I) low performance and unstable; (II) high performance and unstable; (III) low performance and stable; and (IV) high performance and stable. Of the 72 clones evaluated, 17 were classified in group I, 16 in group II, 16 in group III, and 23 in group IV, the latter being of greatest agronomic interest. The biplot revealed that environments ENV2 and ENV3 showed greater discriminative ability among genotypes, while ENV1 exhibited a lower G×E interaction effect. The smaller angle between ENV2 and ENV3 indicated a positive correlation between these environments, suggesting that both provided similar conditions for clone development. These results demonstrate the feasibility of identifying clones with broad phenotypic stability and adaptation to climate variability, contributing to the development of cultivars that are more stable, and productive.