Determination of nuclear DNA content and ploidy in accessions of Vaccinium floribundum Kunth from the Cajamarca region using flow cytometry

Currently, Peru is the leading exporter of blueberries, making this fruit the most important in the country’s export portfolio. Therefore, developing new varieties with improved phenotypic traits and higher nutritional value is of great interest. In this context, Peru is home to native blueberry species such as Vaccinium floribundum Kunth (pushgay), a berry with high nutraceutical potential capable of competing with commercial species. However, achieving this requires its characterization and domestication in order to endow it with competitive traits through genetic improvement programs. This study aimed to determine the nuclear DNA content and ploidy level in 15 germplasm accessions of V. floribundum from the Cajamarca region using Flow cytometry. First, the accessions were micropropagated to obtain plant material with uniform growth and development time. In parallel, preliminary calibration tests of the flow cytometer were carried out. A two-step buffer was used for nuclear extraction, and propidium iodide was employed as the fluorochrome. It was determined that all samples had a diploid (2X) ploidy level, and the average DNA content was 1.244 pg and and approximate value of 608 Mb/1C was estimated.. No clear significant differences were observed among the accessions in terms of genome size. The results show that flow cytometry is a reliable and faster technique for evaluating entire populations compared to other methods, providing a clearer view of the genetic characteristics of V. floribundum . This will allow for future studies on genetic improvement and crossability with commercial blueberry species, aiming to develop varieties with more attractive and competitive commercial traits.