Rootstocks ‘Volkamerian’ lemon (Citrus volkameriana Pasq.), ‘Cleopatra’ tangerine (C. reshni Hort. ex Tanaka), and ‘Amplycarpa’ tangerine (C. amblycarpa Oche) are tolerant to Citrus Tristeza Closterovirus and could be utilized to substitute sour orange (C. aurnatium L. Osbeck). We studied fruit characteristics, polyembryony, and the relationship between them in three rootstocks (‘Volkamerian’ lemon, and ‘Cleopatra’ and ‘Amblycarpa’ tangerines) in fruits harvested in the fall-winter periods of 1998-1999 and 1999-2000. ‘Volkamerian’ lemon presented 154.7 g fruits with 8 to 10 carpels, and 37.9 % polyembryony with 2 to 5 embryos per seed. ‘Cleopatra’ tangerine fruits weighed 74.8 g, with 10 to 14 carpels, and 84.8 % polyembryony with 1 to 26 embryos; and ‘Amblycarp’ tangerines weighed 20.1 g, with 7 to 11 carpels, and 82.1 % polyembryony with 2 to 15 embryos per seed. Fruit morphological characteristics and polyembryony varied according to rootstock and harvest year. The latter significantly affected ‘Volkamerian’ lemon and ‘Cleopatra’ tangerine, but not ‘Amblycarpa’. Number of embryos per seed showed high correlation to number of carpels; while embryo length was positively correlated to fruit weight and equatorial diameter, but negatively to number of embryos.

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