Genomics approach to develop molecular markers for targeted breeding of radish

다국어 초록 (Multilingual Abstract)

Radish is one of the most widely consumed vegetable crops in Korea. Root is the major part of radish supplied to the market, thus the size, shape, and quality of radish roots are main targets of breeding programs. Despite of the importance of this crop, the molecular breeding of radish is still in the rudimentary stage.
In Golden Seed Project, we aim to establish the molecular breeding program of radish using genome-wide approaches. To this end, we selected inbred lines that have distinctive root traits such as yield, shape, disease resistance, and texture. Single nucleotide variation (SNV) among these lines will be identified based on the low coverage genome sequencing data. These SNVs can be used for finding genomic regions associated with root traits from segregating mapping populations which are also in the middle of development.
Korean radish roots are harvested after being grown for only nine weeks. During that period, root biomass reaches to more than two kilograms. While investigating the root growth of radish inbred lines, we found that cytokinin contributes as a key growth regulator that promotes radial growth of radish roots. A difference in growth rates of two distinctive inbred lines was explained by the difference in response to cytokinin. Genes responsive to cytokinin are highly enriched in the cambium, the meristematic cell population that drives radial growth. For comprehensive understanding of genes that affect yields of radish roots, we turned to developing a tissue specific transcriptome data using laser capture microdissection. We expect that the compendium of genomics-based data will help establishing molecular breeding of radish at a fast track.