Phylogenetic relationships among citrus and its relatives as revealed by SSR markers.

ABSTRACT

Phylogenetic relationships among 29 accessions belonging to Citrus, Poncirus, Fortunella, Microcitrus, Eremocitrus, Atlantia and Severinia were investigated using SSR markers. Seven SSR primers generated 114 polymorphic alleles, with an average of 16.3 alleles per primer. Cluster analysis via neighbour-joining method showed that Microcitrus was close to Citrus; Poncirus was distant from Citrus, which suggested that Poncirus could not be derived from Citrus. High frequency of the homozygous SSR locus supported the species status of Fumin trifoliate orange. Separation of neither Papeda and Citrus nor Archicitrus and Metacitrus was well resolved. The present work confirmed citron, pummelo and mandarin as basic species of cultivated citrus since they could be placed into three distinct clusters.