• Selected antioxidant changes in 36 eco-grown tomato cultivars over two years. Lycopene decreased under heat, while ascorbic acid increased. • Some genotypes showed stable or improved antioxidant profiles. • Significant genotype-dependent variation in tomato antioxidant content. The objective of this study was to quantify cultivar-level differences in major antioxidant compounds (vitamin C, lycopene and β-carotene) among 36 tomato cultivars and heirlooms grown under eco-farming conditions across two consecutive years, in order to elucidate genotype-dependent responses to year-to-year environmental variability and to identify cultivars with breeding potential. Cultivar-level differences were quantified based on pooled fruit samples, which provided a representative composite for each cultivar/heirloom. Results of ANOVA test revealed highly significant effects of cultivar, year, and cultivar × year interactions (p < 0.01) for all antioxidant traits, indicating that both genetic background and environmental conditions contributed considerably to phytochemical variation. Lycopene content decreased significantly in 2022 in comparison to 2021, whereas ascorbic acid increased by approximately 40%, while β-carotene remained stable across years. These findings demonstrate that annual climatic variability does not uniformly affect all cultivars but instead leads to genotype-specific antioxidant responses. Identifying cultivars with stable or enhanced antioxidant profiles under contrasting environmental conditions provides valuable insights for future breeding programs aimed at improving nutritional quality and stress tolerance. Preserving tomato diversity and understanding the biochemical properties of heirloom, modern, and wild varieties remain essential for sustainable tomato production, enhanced nutrition, and the conservation of agrobiodiversity.
Dénes et al. (Wed,) studied this question.