International Journal of Molecular Sciences Article Changes in the Content of Organic Acids and Expression Analysis of Citric Acid Accumulation-Related Genes during Fruit Development of Yellow (Passiflora edulis f. flavicarpa) and Purple (Passiflora edulis f. edulis) Passion Fruits Xiaoxue Zhang 1,†, Xiaoxia Wei 2,†, Muhammad Moaaz Ali 1 , Hafiz Muhammad Rizwan 1, Binqi Li 1, Han Li 1, Kaijie Jia 1, Xuelian Yang 1, Songfeng Ma 1, Shaojia Li 3,* and Faxing Chen 1,* 1 College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
[email protected] (X.Z.);
[email protected] (M.M.A.);
[email protected] (H.M.R.);
[email protected] (B.L.);
[email protected] (H.L.);
[email protected] (K.J.);
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[email protected] (S.M.) 2 Fruit Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350002, China;
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[email protected] (F.C.) † Equally contributed authors. Abstract: Organic acids are key components that determine the taste and flavor of fruits and play a Citation: Zhang, X.; Wei, X.; vital role in maintaining fruit quality and nutritive value. In this study, the fruits of two cultivars Ali, M.M.; Rizwan, H.M.; Li, B.; Li, H.; of passion fruit Yellow (Passiflora edulis f. flavicarpa) and purple (Passiflora edulis f. edulis) were Jia, K.; Yang, X.; Ma, S.; Li, S.; et al. harvested at five different developmental stages (i.e., fruitlet, green, veraison, near-mature and Changes in the Content of Organic mature stage) from an orchard located in subtropical region of Fujian Province, China.