Dynamic patterns and diversity of organic acids accumulation in strawberry fruits of different germplasms

Ke Duan, Xiaohua Zou, Jing Yang, Qing-Hua Gao
To study the variations and dynamic accumulation of organic acids in strawberry germplasms, the contents of citric acid and malic acid in fruits were measured with HPLC technique in a total of 138 breeding lines and 24 cultivars widely used in Shanghai. The results showed that the content of citric acid in ripe fruits could account for over 59%, as high as 99.3% of total organic acids. The variations in both total organic acids and citric acid similarly displayed a normal distribution in current collection of strawberry germplasms. The values for ripe fruits of individual cultivars ranged from 6.7 to 62.6 mg g‑1 FW for the citric acid concentration, and 0.2-10.3 mg g‑1 FW for malic acid, with smaller ranges for commercial cultivars than breeding lines. The breeding line L277# (progeny of the cross ‘Akihime’ and ‘Sweet Charlie’) and the cultivar ‘Mariguette’ stand out as the fruits with the highest content of citric acid among all germplasms and among cultivars, respectively. Concerning the malic acid, the breeding line PE8 (progeny of a distant hybridization between cultivar ‘Sweet Charlie’ and the wild strawberry Fragaria nilgerrensis) and cultivar ‘Shenyang’ harbor the highest content, respectively. The changes in organic acid content fit into distinct ranges in different genotypes, suggesting that the influence of cultivation and environment on organic acid accumulation varies with genotype. In fruits from green to ripe stages, a general decline tendency was observed in contents of citric acid and total acids, but that tendency could be integrated with different dynamic patterns, such as a continuously stable decrease, an early decline followed by a recovery since turning stage, and an early increase followed by a decline since white stage. The patterns in dynamic accumulation of malic acid were even more diversified during the development of strawberry fruits, and a higher content of malic acid in ripe fruits than in green fruits was observed in more than half breeding lines tested. This research provides valuable information for the innovative utilization of strawberry resources to develop novel germplasm with diversified flavors. It also serves as a useful reference for improving fruit quality in strawberry cultivation.
Duan, Ke, Zou, Xiaohua, Yang, Jing and Gao, Qing-Hua (2023). Dynamic patterns and diversity of organic acids accumulation in strawberry fruits of different germplasms. Acta Hortic. 1381, 251-258
DOI: 10.17660/ActaHortic.2023.1381.33
strawberry germplasm, organic acids in fruits, citric acid, malic acid, HPLC technique

Acta Horticulturae