Transferability, polymorphism and effectiveness for genetic mapping of the Pummelo (Citrus grandis Osbeck) EST-SSR markers

Pummelo (Citrus grandis Osbeck) is one of the ancestors of sweet orange and economically important cultivated species of the family Rutaceae. The availability of the EST SSR markers for Pummelo represents a promising source to increase the number of markers available for the citrus species. In this study, we evaluated 212 Pummelo EST derived SSR markers (CgEMS) for their transferability across the genera, polymorphism, mapping ability and utility for genetic diversity analysis. Among these markers, 136 were amplified bands, 99 were transferable across the genera. Transferability of CgEMS to C. sinensis, C. reticulata, C. lemon, Fortunella sp and Poncirus sp was 76%, 76%, 75%, 74% and 73%, respectively. In contrast 52 (53%) markers were found to be polymorphic and segregating in a mapping population. Segregating markers can be categorized into four groups: full informative (8%), male informative (15%), female informative (19%) and partly informative (59%). The phylogenetic relationship between the citrus and its relatives obtained with CgEMS was in a good agreement with the established citrus taxonomy and phylogeny. CgEMS could potentially serve as perfect markers for determining variation in phenotype, fingerprinting, mapping and genetic diversity study in C. grandis. Their high level of cross genera transferability of the CgEMS markers has allowed phylogenetic inference within the Rutaceae.

► A total of 212 Pummelo EST derived SSR markers (CgEMS) were developed.
► We evaluated their transferability, polymorphism and mapping ability.
► 52 Markers have the ability of segregating in mapping population.
► These CgEMS markers can be useful for marker assisted selection.