Characterization of fruit quality traits for organic acids content and profile in a large peach germplasm collection

Organoleptic properties play a pivotal role in determining peach fruit quality, affecting both consumers' and market acceptance. In spite of a narrow genetic diversity, peach [Prunus persica L. (Batsch.)] has a remarkable range of fruit taste, mainly driven by the relative amount of sugars and acids. Characterization and exploitation of such variability is a major objective of fruit-quality orientated breeding programmes. In this study, a peach collection of 201 accessions was dissected for important fruit quality traits, with a particular focus on acidity and organic acids content. Fruit acidity was titrated and ten organic acids (oxalate, cis-aconitate, citrate, tartrate, galacturonate, malate, quinate, succinate, shikimate and fumarate) were detected through HPLC and UHPLC-MS. Malate and citrate are the most abundant accounting for the 62 % and the 22.6 % of total organic acids, respectively, and suggesting their largest contribution to the overall peaches acidity. Results reveal also a genotype-dependent contribution of specific organic acids and a low seasonality-effect on peach acidity and organic acid patterns. Collectively, this work provides an overview of the phenotypic variation associated with organic-acid related traits useful for supporting the ongoing breeding works.

Automated summary

Organoleptic properties are crucial for determining peach fruit quality, with sugar and acid levels driving the range of fruit taste in spite of a narrow genetic diversity. This study identified malate and citrate as the most abundant organic acids in peaches, contributing significantly to overall acidity. Results also showed genotype-dependent contributions of specific organic acids and minimal seasonality effects on peach acidity and organic acid patterns, providing valuable insights for ongoing breeding programs.