Experiments were performed in fruits of the following Citrus species: orange (Citrus sinensis cv. Navelina), Clementine (Citrus clementina cv. Clemenules), and Satsuma mandarin (Citrus unshiu cv. Owari), and red grapefruit (Citrus paradisi cv. Star Ruby). Trees of Navelina orange, Clementine mandarin and Star Ruby grape- fruit were growing in the Spanish Citrus Germplasm Bank (IVIA, Moncada, Valencia, Spain) and those of Satsuma mandarin in a commercial orchard located in Lliria (Valencia, Spain).