Genome Sizes, Ploidy Levels, and Base Compositions of Styrax Species and Cultivars

Styrax L. is a genus of ≈130 species, many with horticultural traits interest, though sparsely represented in cultivation. Previous studies reporting chromosome counts have established base number x = 8 and provided evidence diploid, tetraploid, pentaploid, hexaploid levels within the genus, including more commonly cultivated japonicus Siebold & Zucc. being reported as pentaploid. Little has been relative to genome size Styracaceae. We conducted flow cytometry using fluorochromes propidium iodide (PI) 4′,6-diamidino-2-phenylindole (DAPI) estimate 2C ploidy 47 accessions representing 15 species composition subset 9 6 species. Cytologic analysis chromosomes was completed on confusus Hemsl. for calibration size. Diploids, tetraploids, pentaploids, hexaploids, octoploids were identified. Relative ranged from 1.38 6.61 pg. This survey confirms published americanus Lam., obassia Zucc., redivivus (Torr.) L.C.Wheeler (diploid), S. (pentaploid); suggests alternate and/or series grandifolius Aiton (diploid) hookeri C.B.Clarke (octoploid); establishes glabrescens Benth., odoratissimus Champ. ex officinalis L., platanifolius Engelm. Torr., ramirezii Greenm., wilsonii Rehder confusus, hemsleyanus Diels (tetraploid), fortunei Hance (diploid hexaploid).