The effect of rootstocks on sugars, acids, carotenoids, chlorophylls, and ethylene of Satsuma mandarin (Citrus unshiu)

This study aimed to evaluate the effect of rootstocks on fruit sugars, organic acids, and carotenoids. The contents of sugars and organic acids in fruits were determined by HPLC. Total acidity (TA), total soluble solids (TSS), and pH value of the juice were also evaluated. Total carotenoids and chlorophylls contents were measured using a spectrophotometer. The content of ethylene in fruits was determined by gas chromatography.  HPLC analysis of the juice allowed the detection of 3 sugars and 2 acids. Sucrose was the dominant sugar for all rootstocks. Total sugars ranged from 93.54 (mg/mL) (Flying dragon) to 111.54 (mg/mL) (Swingle citrumelo). Total acids changed from 9.50 (mg/mL) (Trifoliate orange) to 11.45(mg/mL) (Flying dragon). The ascorbic acid content varied from 0.20 (mg/mL) (Flying Dragon) to 0.32 (mg/mL) (Sour orange). The pH value ranged from 3.14 (Flying dragon) to 3.50 (Trifoliate orange), TSS content changed from 10.70 (%) (Flying dragon) to 11.10 (%) (Swingle citrumelo), TSS/TA varied from 11.75 (Flying dragon) to 13.45 (Trifoliate orange). The juice content ranged from 52.18 (%) (Flying Dragon) to 55.63 (%) (Sour orange). The amount of fruit production changed from 15 (Kg /tree) (Flying dragon) to 115 (Kg /tree) (Swingle citrumelo). Total carotenoids varied from 0.09 (Swingle citrumelo) to 0.15 (Sour orange and Flying dragon) (mg/gr DW). Among the four rootstocks evaluated, Swingle citrumelo demonstrated the maximum level of sugars and TSS. The study concluded that the rootstocks can affect sugars, acids, and, carotenoids contents of the fruits.