2019 ASHS Annual Conference

Southern highbush blueberry (SHB) was developed by crosses between northern highbush [NHB (V. corymbosum L. 2n=4x=48)] and Florida’s indigenous blueberry species (V. darrowii Camp. 2n=2x=24) to expand the geographic limits of highbush blueberry production. Due to the multiple times use of interspecific hybridization in breeding process, all SHB cultivars are assumed to contain genomic segments introduced from one or more of the Vaccinium species, resulted in germplasm showing phenotypic variation for different traits. Because of the complex genome and lack of molecular tools, the genetic diversity and population structure of SHB germplasm have never been fully assessed. In this study, a double digest restriction-site associated DNA sequencing (ddRAD-seq) method was used to analyze the population structure and asses the genetic diversity within a panel of 168 SHB accessions, 30 NHB accessions, 15 rabbiteye blueberry [RE (V. virgatum Aiton 2n=6x=72)] and 10 diploid species including V. darrowii, V. corymbosum, V. elliottii, V. tenellum, and V. pallidum. Structure analysis indicated that SHB contains genomic segments introduced from other Vaccinium species. Principal component analysis revealed that RE cultivars could be clearly distinguished from highbush cultivars. Although NHB and SHB were grouped together, we were able to find principal components that partially discriminate between them.