Four mandarin cultivars were characterized for seed number per fruit and polyembryony, three of them are used as parents in the Departamento de Horticultura e Silvicultura - Universidade Federal do Rio Grande do Sul citrus breeding program. Mandarin fruits were sampled from the Experimental Station citrus collection, in Eldorado do Sul, RS, and their seeds were extracted and counted. In esterile chamber, the embryos were excised from seeds and cultured in vitro on MT medium (Murashige & Tucker, 1962), at 26±3°C with a 16h photoperiod. The mandarin cultivars Caí, Montenegrina (Citrus deliciosa Tenore), Poncã (C. reticulata Blanco) and King (C. nobilis Loureiro) had an average of 16, 14, 8 and 24 viable seeds per fruit, respectively, and 5.7, 5.7, 7.7 and 3.2 embryos per seed. Monoembryonyc seed production was low, except in King cultivar, which had 20.4% of monoembryonic seeds. Albine embryos were also detected, which were part or total content of some seeds. In general, the species showed significant differences in relation to the studied traits. The similarities between the C. deliciosa cultivars are strong evidences for the hipotesis that Montenegrina is originated from Caí.
Citrus spp.; mandarins; seeds; apomixis; polyembryony; embryo culture
