The Effect of Rootstocks on the Sugars, Acids, Carotenoids, Chlorophylls and Ethylene of Clementine Mandarin (Citrus clementina)

Investigations have demonstrated that ratio of sugars to organic acids affects the particular taste of citrus fruit and carotenoids are essential for prevent of the disease.  It seems that some rootstocks enhance the ripening of fruits and stimulatethe biosynthesis of sugars and carotenoids. The aim of this study was to evaluate the effect of rootstocks on sugars, organic acids andcarotenoids of fruit. The content of individual sugars and organic acids in fruits were determined by HPLC. Total acidity (TA), total soluble solids (TSS) and pH value of juice was also evaluated. Total carotenoid and chlorophylls content was measured using a spectrophotometer. The content of ethylene in fruits was determined by Gas chromatograph.   HPLC analysis of juice allowed to detection of 3 sugars and 2 acids.  Sucrose was the dominant sugar for all rootstocks. The amount of total sugars ranged from 102.27 (mg/ml) (Flying dragon) to 118.07 (mg/ml) (Orlando tangelo). The amount of total acids changed from 6.62 (mg/ml) (Trifoliate orange) to 8.48 (mg/ml) (Flying dragon). The amount of ascorbic acid varied from 0.44 (mg/ml) (Trifoliate orange) to 0.68(mg/ml) (Orlando tangelo).The pH value ranged from 3.65 (Flying dragon) to 3.95 (Orlando tangelo), TSS content changed from11.2 (%) (Flying dragon) to11.9 (%) (Orlando tangelo), TSS/TA varied from15.13 (Flying dragon) to 20.88(Orlando tangelo). Juice content ranged from 49.29 (%) (Trifoliate orange) to 54.47 (%) (Orlando tangelo). The amount of fruit production changed from 12 (Kg /tree) (Flying dragon) to 83(Kg /tree) (Orlando tangelo). The amount of total carotenoid varied from 0.12 (Murcott) to 0.15(Orlando tangelo, Sour orange, Flying dragon) (mg/gr DW). Among the six rootstocks evaluated, Orlando tangelo demonstrated the maximum rate of sugars, pH, TSS, TSS/TA, juice, ascorbic acid and carotenoids. As an outcome of our investigation, we can express that the rootstocks can affect the amount of sugars, acids andcarotenoids of fruit.

The Effect of Rootstocks on the Sugars, Acids, Carotenoids, Chlorophylls and Ethylene of Clementine Mandarin (Citrus clementina) Keywords:

carotenoids , Citrus rootstocks , Ethylene , organic acids , Sugars