Genus Begonia is prominent ornamental bedding and potted flower crop, encompassing types such as Rieger Begonia (Begonia × hiemalis), Tuberous Begonia (Begonia tuberhybrida), and B. semperflorens, which are extensively cultivated. Building upon the breeding methodology of Rieger Begonia, this study endeavors to utilize Tuberous Begonia as the maternal parent and integrate the attributes of B. semperflorens to develop innovative interspecific hybrid varieties. Interspecific hybridization was accomplished by using Tuberous Begonia 'Fortunate' as the female parent and B. semperflorens as pollen donor through embryo rescue techniques, resulting in successful interspecific offsprings. Flow cytometry analysis revealed the expected DNA content combination in the hybrids. Furthermore, Random Amplified Polymorphic DNA (RAPD) analysis confirmed the authenticity of the interspecific hybrids by exhibiting specific bands of both parents. The plant type, basal branching habit, and leaf shape of the hybrids resembled those of the male parent, B. semperflorens, while the double flower characteristic inherited from the female parent. Additionally, the hybrids exhibited year-round flowering without requiring photoperiod treatment and showed no apparent dormancy, rendering them suitable for continuous production. These hybrids are also exhibiting robust branching habits and possess distinctive plant traits compared to commercially available Rieger Begonias. They are particularly suited for cultivation in hot and humid regions. Evaluation of production and growth advantages indicated their capability for year-round supply and commercial production. Applications for Plant Variety Rights have been submitted for these hybrids in Taiwan.
