Diversity in nuclear DNA content and ploidy level of <italic>Hedychium</italic> species and hybrids.

Hedychiums are multipurpose plants cultivated as ornamentals because of their multicolor and showy and scented flowers and as medicinal plants because of their essential oils that have been found to possess antimicrobial and insecticidal properties. There is often taxonomic and botanical confusion about <italic>Hedychium</italic> species and cultivars because of the apparent existence of more than one cytotype within several <italic>Hedychium</italic> species, most likely because of the ease with which these species hybridize. Nuclear DNA content (2C-DNA) was determined for the first time in 23 <italic>Hedychium</italic> species and hybrids. The 2C-values ranged from 1.70 pg to 3.98 pg. We also determined the chromosome number of one species, <italic>Hedychium stenopetalum</italic>, which was found to be diploid (2<italic>n</italic> = 2<italic>x</italic> = 34), supporting the widely held view that the basic chromosome number in <italic>Hedychium</italic> is <italic>x</italic> = 17, and the existence of different cytotypes is most probably attributable to natural hybridization. Our results should be helpful not only in clarifying the botanical and taxonomic confusion in <italic>Hedychium</italic> but also in paving the way for a sound breeding program for this increasingly important ornamental ginger. [ABSTRACT FROM AUTHOR]