Orchid is a major floral crop around the world
and Dendrobium hybrids are considered to be one of the
most popular orchids. In vitro germination of hybrid seeds
is a common practice among orchid growers, however, in
many cross pollinations the embryos may not develop to
maturity, leading to poor seed germination. The effect of
seed maturity and sucrose concentration were investigated
via asymbiotic germination of nobile Dendrobium hybrids.
Capsules were harvested from two hybrids (Den. Lucky
Girl 9 Den. Second Love ‘Kirameki’ and Den. Lucky
Girl 9 Den. Hamana Lake ‘Kumi’) and one selfing of Den.
Second Love ‘Kirameki’ at 2, 3, 4, and 5 months after
pollination and immature seeds were taken. Immature
seeds from 3- to 5-month old capsules could be successfully
germinated on Hyponex based medium. Immature
seeds from 4-month old capsules showed greatest germination
rate of tested treatments, whereas 3-month old
immature seeds showed the least germination. After
6 weeks of in vitro culture, protocorms derived from
embryos developed on every concentration of sucrose, but
germination was greater at lower concentrations. Greater
concentration of sucrose decreased normal-developed
protocorms.