Genome Size and Ploidy Level of Commercial Eustoma grandiflorum (Raf.) Shinners

Eustoma grandiflorum is considered as the ‘next rose’ in floriculture, ranking top-ten in cut flowers. In this study, we investigated the ploidy level and genome size of 28 commercial cultivars of E. grandiflorum through flow cytometry. The analysis of each cultivar showed that only one cultivar was tetraploid, whereas the rest were diploids. By comparing with a standard reference genome of Solanum lycopersicum, the genome size (1C) of E. grandiflorum cultivars ranged from 1.26 to 2.64 Gb, which was in line with their ploidy levels and previous data. Although a large number of plant phenotypic diversities were observed in the experimental cultivars, the genome size displayed little difference in diploids, indicating that the monoploid DNA amount of E. grandiflorum is relatively conserved during artificial selection. It is possible to sequence the genome of E. grandiflorum using the latest sequencing techniques, which could provide a solid foundation for molecular biology research and molecular breeding for E. grandiflorum.