New Estimation of Genome Size in the Highly Diverse Genus Begonia

Begonia is one of the most diverse plant genera, native to tropical and subtropical regions worldwide. Throughout its long cultivation history, Begonia has become widely spread across the Americas, Asia, and Africa. In addition to morphological, ecological, and geographic origin differences, Begonia species also vary significantly in genome size. In this study, flow cytometry was employed to estimate the genome sizes for 93 Begonia accessions, including plants from 68 identified species, eight unassigned species and hybrids, representing 26 sections of the genus. A total of 68 accessions are newly reported, including 47 identified species, eight unassigned species and hybrids. The results showed a wide range of 2C DNA values, from 0.47 pg in Begonia convolvulacea to 2.39 pg in Begonia polygonoides . Sections Knesebeckia , Parvibegonia , and Tetraphila had the largest mean genome sizes, whereas Wagenaria had the smallest. Significant variation in genome size was observed among individual accessions within the Central and South American sections of Ephemera , Gireoudia , and Pritzelia . These data expand the genomic foundation for Begonia , providing a valuable resource for future genomic and genetic research, advancing breeding efforts in this genus.