Looking in the Scaffold 22 Hotspot for Differentially Regulated Genes Genomic Sequence Variation in Romanian Blueberry Cultivars

Abstract

Since its domestication about a century ago in North America, highbush blueberry (Vaccinium corymbosum L.) has gained appreciation by consumers worldwide, and the demand for new blueberry varieties is increasing. Whole-genome resequencing can help plant breeders to decrease the time needed to create novel varieties by identifying novel genes linked to fruit-quality traits. The present study analyzed the genetic variability of eight V. corymbosum genotypes, seven Romanian varieties (‘Prod’, ‘Vital’, ‘Azur’, ‘Simultan’, ‘Delicia’, ‘Compact’, and ‘Safir’), and the American variety, ‘Bluecrop’. The analysis of the first ~10 Mb from scaffold 22, a hotspot of genomic variation, in the above-mentioned varieties revealed multiple differences in 11 upregulated and 50 downregulated genes involved in fruit growth and development. Of these differentially regulated genes, two upregulated and five downregulated genes were fully covered by at least 1× coverage depth by sequencing. The genes’ sequence analysis confirmed the high genetic variability of the region, with most of the genes presenting numerous SNPs and some InDels, and indicated that an attempted 10× medium-coverage depth of sequencing for V. corymbosum varieties yields useful preliminary data for use in breeding programs.