Sequence tagged microsatellites polymorphism : an alternative tool for cultivar identification and evaluation of genetic relationship in #Citrus#

Genetic relationships among 92 individuals of 8 more economically representative species of Citrus (C. reticulata, C. sinensis, C. aurantium, C. paradisi, C. maxima, C. lemon, C. aurantifolia and C. medica) and 17 other species are estimated by the amplification of 10 loci of SSR named STMS (Sequence Tagged Microsatellites). The potential of STMS for cultivar identification in each species has been evaluated and we have performed a neighbour joining analysis in the basis of a dissimilarity matrix among the different genotypes. Polymorphism of 8 STMS was sufficient to obtain genetic aggregations where three main groups were clearly identified: the orange-mandarin group, the pummelo-grapefruit group and the lime-citron-lemon group. The Citrusspecies relationships were in broad agreementwith those established by previous analyses based on molecular markers and morphological traits, suggesting that SSR data will be useful for exploring intra-generic Citrus genetic taxonomy. The studied microsatellites have not allowed distinguishing varietieswithin some of the species known to have evolved by somatic mutations like sweet oranges and sour oranges. However, polymorphism is detected among lemon varieties. (Resume d'auteur)