Phenotypic and genetic characterization of three different types of dangyooza (Citrus grandis), Korean landrace citrus

Abstract

Dangyooza (DY), a Korean landrace citrus similar to pomelo (Citrus grandis L. Osbeck), has been consumed as a fruit and used in folk remedies to treat colds for centuries, and it is still used as a garden tree. DY has two natural variants, the buk-daengyooza (BDY) and the seol-daengyooza (SDY) based on distinguishable phenotypic fruit characteristics. However, there is little scientific analysis available not only on the morphological and chemical properties but also on the genetic basis of these natural variants. To gain a better understanding of DY, several morphological, phytochemical, chromosomal, and genetic traits were analyzed in DY and its natural variants, BDY and SDY. Morphological characteristics such as leaf and fruit shape, fruit hardness, and peel thickness were used to discriminate SDY from DY and BDY. Notably, SDY produced smaller fruit with thinner peels than those of DY and BDY. The major flavanones occurring in citrus were also markedly higher in SDY than those of DY and BDY. However, chromosomal configuration and genetic diversity analysis using random amplified polymorphic DNA, simple sequence repeat, and plastid trnL/F barcoding markers were unable to clearly discriminate the phylogenetic relationships among the DY types. This suggests that SDY might have arisen from somatic mutation, perhaps as a nucellar seedling.